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SERVICE TRAINING Foreword
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430 EXCAVATOR SERVICE TRAINING
Table of Contents
1. HYDRAULICS LOAD SENSING........................................................................... 1-1
2. HYDRAULICS HYDROSTATIC ............................................................................ 2-1
3. ELECTRICS............................................................................................................. 3-1
4. MAINTENANCE....................................................................................................... 4-1
5. SAFETY................................................................................................................... 5-1
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SERVICE TRAINING Foreword
01-2005 ii
FOREWORD
This manual is primarily intended for the training of mechanics with some knowledge of hydrauliccomponents, not total beginners.
Its principal objective is to give the reader the knowledge required for a better understanding of theequipment and for effective maintenance and repair of the different hydraulic components.
We would like to draw your attention to the fact that this manual is not intended to replace training given incollege; it is a supplement to it.
The goal is to give the basic explanation of the BobcatExcavator without theory, with the maximum of detail
given to the components.
The hydraulic drawings in this manual are made up in several stages for a better understanding of thecomplete system.
The original Bobcat430 Service Manual remains the principal tool to use in case of repair.
JCL Dubelloy
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HYDRAULICS
LOAD SENSING
430 S/N 562911001 & above
430 S/N 563011001 & above
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Table of Contents
1. Specifications .................. ................... .................... .................... ................... ..........1-5
2. Hydraulic symbols....................................................................................................1-6
3. Hydraulic schematic...............................................................................................1-13
4. Components layout ................. ................... ................... ................... ................... ...1-15
5. External gear pump, fixed displacement ................... .................. ................... ........1-16
6. Variable displacement piston pump .................. .................... ................... ..............1-17
7. Spool valve layout..................................................................................................1-18
8. Load sensing spool valve function .................. .................... ................... ................1-19
9. Load sensing relief valve ................. ................... ................... ................... .............1-22
10.Spool valve section................................................................................................1-23
11.Port relief valve......................................................................................................1-25
12.Swing motor...........................................................................................................1-26
13.
Drive motor ................. .................... ................... .................... ................... .............1-28
14.Center post ................. .................... ................... .................... ................... .............1-31
15.Hydraulic cooling motor .................. .................... ................... ................... .............1-32
16.Pilot oil feeding block.............................................................................................1-34
17.Solenoid valve ................... .................... ................... .................... ................... ......1-35
18.Pressure reducing valve ................... ................... ................... ................... ............1-36
19.
Joystick..................................................................................................................1-37
20.Direct to tank valve ................... ................... ................... ................... ................... .1-38
21.Cylinder .................. .................... .................... ................... .................... ................1-38
22.Pressure and flow test .................. ................... .................... ................... ...............1-39
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1. SPECIFICATIONS
Hydraulics
2 x 38 L/minHydraulic pump
1 x 29 L/minCircuit pressure 240 bar
Boom port relief valve 270 bar
Dipper port relief valve 270 bar
Bucket port relief valve 270 bar
Auxiliary port relief valve 180 bar
Blade port relief valve 270 bar
Hydraulic reservoir 37 L
Breather cap 0,34 bar
Fan motor relief valve 69 bar
Auxiliary flow 62 L/min
Swing motor pressure 141 bar
Pilot pressure 30 bar
Cycle times
Bucket curl 2,6 s.
Bucket dump 1,8 s.
Dipper retract 3,3 s.
Dipper extend 2,7 s.
Boom raise 4,6 s.
Boom lower 5,4 s.
Offset left 6,9 s.
Offset right 5,7 s.
Blade raise 2,4 s.
Blade lower 3,1 s.
Swing 8,8 RPM
Travel high speed 4,7 Km
Travel low speed 2,4 Km
Engine speed 2600 RPM
Date Model Prefix/SN Fast Track Load Sensing
Apr 04 430 G 562711001 Yes No
Dec 04 430 AG 562911001 No Yes
Feb 05 430 HAG 563011001 Yes Yes
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2. HYDRAULIC SYMBOLS
Fixed displacement pump
used to operate all hydraulic functions
Variable displacement pump
used to operate all hydraulic functions
Variable displacement pump
operates the travel system
One way motorused to cool the hydraulic oil
Fixed displacement motor
operates the swing motor
Two speed drive motor
operates the travel system
Double variable piston pump
operates the hydraulic system
Center post
allows the upper frame to turn 360 degreeswithout damaging the hoses
Diesel engine
Direct operating relief valve
Protects the hydraulic circuit from peak pressures
Piloted/adjustable relief valve
to adjust the circuit pressure at a certain value
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Relief valve with anti-cavitation valve
to protect the hydraulic circuit from over pressure andto avoid cavitation
Pressure reducing valve
it uses flow from the hydraulic circuit andreduces the pressure to feed the joysticks
One way restrictor
to limit the flow in one directionbut not in the opposite direction
Bouble piloted check valveto keep the offset cylinder in the chosen position
Quick coupler
Pressurized filler cap
to maintain a low pressure inside the reservoirto avoid cavitation in the hydraulic circuit
Hydraulic reservoir
Hydraulic filter with by-pass
to filter the hydraulic oil
Hydraulic cooler
to cool the hydraulic oil
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Drain line filter
to catch solid particles of different components
Piloted operated spool
this spool is controlled by a joystick
Electric operated spool
this spool is controlled by the control panel
Electro/hydraulic operated spoolthis spool is controlled by the control panel
Spool operated by solid linkages
operated by foot or hand
Centering spring
to keep the spool in the center position
Detent mechanism
to block the spool in a given position
Progressive spool
used in the load sensing circuit
Double acting cylinder
Double acting cylinder with cushions
Holding valve
used on lifting devices, it controls the lowering speed andis a safety in case of a hose burst
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Mechanically applied brake
used on the drive system
6/3 spool parallel design
used for hydraulic function
6/3 spool series design
used for hydraulic function
Load sensing spool and compensator
Hydrostatic pump, servos operated
3/2 solenoid
used to operate the front auxiliaries
3/2 solenoid
used to operate the pilot oil
3/2 spool
operates different hydraulic components
3/2 spool
routes the return flow from the auxiliaries to the spool valveor directly to the tank
Selector valve
used to select a signal and send it to a hydraulic component
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Back pressure valve
Accumulator
Double stage relief valve
electrically operated
Replenishing/relief valve
used in close loop transmission
Double stage relief valve
hydraulically operated
Flushing and back pressure valve
used in close loop transmission
Feeding lines
Drain lines
Pilot lines
Components assembly
Connected lines
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Non connected lines
Circuit pressure(red)
Main return lines (blue)
Charge pressure or pilot oil(yellow)
Drain and pump inlet (green)
Static oil (brown)
Bleed valve
to cancel the LS signal in the neutral position
Joystick
to operate all the hydraulic functions
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Variable piston pump
with power spool, flow spool and torque limiter
Variable piston pump
with the torque limiter
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3. HYDRAULIC SCHEMATIC
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Legend
1 Secondary auxiliary (optional) 13 Drive joystick
2 Offset cylinder 14 Hydraulic cooler
3 Boom cylinder 15 Main hydraulic filter
4 Dipper cylinder 16 Hydraulic reservoir5 Bucket cylinder 17 Pilot Block
6 Front auxiliary 18 Hydraulic pump
7 Swing motor 19 Cooling motor
8 Double piloted check valve 20 Drain filters
9 Spool valve 21 Right drive motor
10 ISO/STD converter 22 Left drive motor
11 Right joystick 23 Centre post
12 Left joystick 24 Dozer blade cylinders
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4. COMPONENTS LAYOUT
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5. EXTERNAL GEAR PUMP, FIXED DISPLACEMENT
External gear pumps have two gears in mesh, closely fitted inside a housing.
The drive shaft drives one gear. Shaft bushing and machined surfaces or wear plates are used to seal theworking gears.
Operation is quite simple:
As the gears rotate and come out of mesh, they trap inlet oilbetween the gear teeth and the housing.
The trapped oil is carried around to the outlet chamber.
As the gears mesh again they form a seal which prevents oil fromgoing back to the inlet.
The oil is forced out at the outlet port and sent through the system.This oil is pushed out by a continuous flow of trapped oil cominginto the outlet chamber with each rotation of the gears.
At the inlet side, gravity feeds in more oil from the reservoir toreplace that drawn out by the running gears.
Gear pumps have two pressurized plates (see figure A and B)working against the gears to increase pump efficiency.
A small amount of pressure oil is fed under the backing platespressing them against the gears and forming a tighter seal againstleakage.
View of seals around compensation plates.
The oil sent out the outlet of the pump is also routed through an
internal channel to pressurize three quarters of the total surface ofthe compensation plate, the inlet side is not pressurized because itis at the atmospheric pressure.
The gear pump used in the excavator operates the cooling system.
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6. VARIABLE DISPLACEMENT PISTON PUMP
Legend
1 Pump shaft 5 Gear pump
2 Swash plate 6 Torque adjusting screw
3 Barrel unit 7 Set of springs
4 Destroke pistons (x3) 8 Wear plate
When the drive shaft (1) of the piston pump is rotated by the engine, the piston block (3) which is splined tothe drive shaft also turns.
The piston block contains 10 piston assemblies which have a free swiveling shoe swaged on the ball end ofthe piston assembly. Five pistons deliver flow to P1 and the other five to P2, note the position of the grooves.
The shoe end of the piston rides against a smooth surface of the swash plate (2). The piston shoe folows theinclined surface of the swash plate (2) and begins moving in the piston block (3) bores. Half of the pistonassemblies are being pulled out of the piston block (3) while the remaining half of the pistons are beingpushed back into the piston block. This action causes the piston pump to pump oil.
The pistons being pulled out from the piston block (3) suck oilinto the piston block bores through the suction port and inletslot.
As the pistons cross top dead centre, the pistons push the oilout of the piston block bores and into the pressure slot (P1 andP2) and out the pressure port.
Each piston assembly completes this cycle, each revolution ofthe pump shaft causes a continuous even flow of oil from thepump.
The maximum swash angle of this pump is around 18.INLET
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7. SPOOL VALVE LAYOUT
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8. LOAD SENSING SPOOL VALVE FUNCTION
Spool valve in neutral
When the engine is running, the hydraulic pump delivers flow to the spool valve and the flow is blockedthere. At that time the flushing valve (3) opens to route its flow back to the tank.
(This is called an open centre load sensing cicuit)
The cylinder is kept in a chosen position due to the close port of the spool valve.
The stand-by pressure is adjusted with the spring force located behind the flushing valve (3).
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Spool shifted
The spool (1) is shifted to the left, the flow from the pump is routed through the spool and pushes thecompensator (2) to the left, that flow is divided in two directions.
The first direction becomes the load sensing signal and is routed to the bleed valve (4), to the one way orifice(5) and the LS signal which closes the flushing valve (3) by means of the jumper hose (7).
The flow from the second direction from the compensator is routed back to the spool (1) then opens the loadcheck valve and finally to the base end of the cylinder. The rod end routes its flow back to the spool section
and to the main return line.
The flushing valve (3) is adjusting the needed flow to each cylinder (s) or motor (s) depending the position ofthe spool (1).
When the maximum working pressure is reached, the LSRV (6) opens to release the LS signal then theflushing valve opens to route the flow back to the tank.
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The spool valve inlet section has different in and outlet, a tank port (T), a feeding port (P), a load sensingport (LS) and a jumper port (J).
The pump flow is routed to the inlet (P) and the flushing valve (3) which is in the close or working position.The main return (T) is routed to the cooler and filter and finally to the reservoir. The load sensing channel is
connected to all compensators and is routed back to the flushing valve (3).
The load sensing relief valve (LSRV) (2) opens when the maximum working pressure is reached.
The flushing valve (3) is metering the flow to the outlet depending the position of the joystick(s).
The bleed valve (2) releases some flow back to the main return, it is an fixed orifice. It will dump the loadsensing signal back to the reservoir when no functions are operated.
A diagnostic coupler is located onto the inlet section to check the working pressure and the stand-bypressure.
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9. LOAD SENSING RELIEF VALVE
The main relief valve located in the inlet section of the spool valveis a direct operating relief valve.
It is assisted by its opening due to the special washer (2).
The pressure setting is adjusted by the screw (4) and themechanical force of the spring (3) will keep the valve (1) closeduntil the maximum pressure setting is reached.
The maximum circuit pressure is reached, the valve (1) opens dueto the hydraulic oil force with the assistance of the concavewasher.
This valve is called LSRV (Load Sensing Relief Valve)
Look at the action of the oil against the concave washer when thevalve opens.
1
2
3
4
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10. SPOOL VALVE SECTION
Neutral position
This type of spool valve is a new concept, it is mounted by means of tie bolts (three) and with ten sections tooperate all the functions. This is a compact load sensing spool valve and is operated with a compensator (1)in each sections, the spool which has the load chek valve (2) located inside the spool (5). The outlet port can
have different valve such as a port relief valve (4), a plug (3) or an anti-cavitation valve.
In the neutral position, the ports (A and B) are closed, the (P) chanel is kept under the stand-by pressureadjusted by the spring of the flushing valve located inside the inlet section.
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Spool shifted
The spool is shifted to the left, the stand-by pressure (P) routes its oil to the compensator (1) which opens,the flow enters inside the spool (5) opens the load check valve and then routes its flow to the outlet port (B).
The flow from the outlet (B) is routed to one of the equipment and back to the spool section and finally to thetank chanel (T).
The load sensing signal (LS) is routed to the flushing valve which is metering the flow between the feedingchanel and the outlet depending the demand of flow of the digging equipment.
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11. PORT RELIEF VALVE
The port relief valve is in the close position, the outletport (red) is connected to one of the diggingequippment.
The internal channel (blue) is routed to the mainreturn.
As soon as a peak pressure appears, the internal
needle moves to the right and opens to release someflow to the main return line.
In case of cavitation, the relief valve will move to theleft and opens. The tank channel feeds the neededflow to the corresponding cylinder.
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12. SWING MOTOR
The swing motor is a geroller type and is assembled byfour bolts onto the motor carrier (see below).
The relief valves (1) are part of the motor cover, the reliefvalves have a lower setting than the circuit pressure. (168bar).
Futher rmore in the head, we find two check valves (4) toprevent cavitation, the feeding port (3) is connected to themain return and feeds the anti-cavitation valves.
The ports (2 and 5) are used to rotate the swing motor.
The hydraulic circuit main return is also connected to the
ports (6 and 8), this is also a feeding for the anti-cavitationvalves and the dog bone area (9).
The back pressure of the circuit is high enough to lubricatethe splines (9) and the motor shaft (10).
The port (7) is a free drain line to tank.
Swing motor carrier
The carrier consits of a housing with two tapered bearings(which are maintained preloaded) and the shaft (see
below).
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Geroller motor, cutaway
The geroller swing motor is a fixed, positive displacement motor that provides the output necessary to swingthe upper frame of Bocat
mini excavator.
The main elements of the geroller swing motors are are the outer ring, rotor star (3) and a disk valve (2).
The disk valve (2) and the back of the rotor star (3) function together to direct the incoming high pressure to
the proper oil chambers and direct the return oil back to the end cap (1).
The high pressure (red) oil flows in sequence from the disk valve (2) to the rotor star back to the disk valve(3) and finally to one of the oil chambers. In actual operation four of the oil chambers are filled with highpressure oil (red) at one time. A similar situation also occures in the return oil path. The disk valve (2) androtor star (3) direct the path of the four oil chambers with low pressure oil to the end cap (1).
Notice that one oil chamber is always in transition from low pressure to high pressure oil. Each time the rotorstar turns, it redirects high pressure oil to the chamber in transition and redirects oil to the remaining oilchamber so there are always four oil chambres filled with high pressure oil and four filled with low pressureoil.
When a chamber is filled with high pressure, the rotor star (3) is forced towards the middle of the outer ring
and split by the rotors. The rotor star (3) rotates clock wise until it is in the new position.
Also notice that the rotor (3) does not turn on its axis. Rather it walks eccentrically around the outside ring.Becouse of this, the circumference of the rotor appears to rotate in the opposit direction to the rotor. Dont beconfused, the rotor actually is turning clock wise.
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13. DRIVE MOTOR
Legend
1 Rear cover 9 Filler plug
2 Rotating group 10 Reduction box housing
3 Motor housing 11 Lip seal
4 Face seals 12 Second speed piston5 Motor bearings 13 Swash plate
6 Adjusting nut 14 Motor piston
7 Reduction gear box 15 Drive shaft
8 Front cover 16 Second speed piston
This drive motor is an axial piston swash plate type. The front part consists of a planetary gear box (7) whichis lubricated with 90 W gear oil, two ball bearings (5) held by a counter nut and two face seals (4). The midsection has a rotating group (2), a wear plate and the swash plate (13). The swash plate (13) can take twopossible positions, maximum swash angle for low speed and minimum swash angle for high speed.
The rear cover has several components such as a brake spool, a two speed spool (16) and its two speedpiston (12). The A and B ports are used to drive forward and reverse.
The second speed is controlled by a solenoid located in the pilot control block.
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Drive motor not activated
When the drive motor is not used, the double check valve is closed. The second speed spool is in the neutralposition, the two cylinders (12) route their oil free into the drain lines.
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Driving in the first peed
The spool in the main spool valve is shifted, the oil is routed to the double check valves which opens, thisflow (red) is then routed to the motor it self. The drive motor start to run, this is the low speed mode ormaximum capacity and high torque. The signal to the two speed spool is blocked off. The return of the drivemotor (blue) is routed back to the main spool valve.
Driving in the second speed
The solenoid located in the pilot feeding block sends pilot oil to the Pp port which then moves the secondspool to the right. The high pressure will destroke the swash plate with one of the two cylinders. We are thenin the high speed or low displacement and low torque mode.
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14. CENTER POST
Legend
1 Drive motors drain return port 5 Second speed connection port
2 Dozer blade port 6 Centre post housing
3 Drive motor port 7 Centre post piston
4 Drive motor port 8 Combined seals
The purpose of the centre post is to feed hydraulic oil from the upper part of the excavator to the hydrauliccomponents located in the lower frame and to give the possibility to rotate the upper frame for 360 degrees.
The centre post is made of two main parts:
A central piston (7) which has internal passages drilled and seals and an external housing which has in andoutlet ports. The upper part of the centre post is mounted on the upper frame by a pin (X) and rotates with itduring operation. The housing (6) is bolted onto the lower frame and does not move during operation.
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15. HYDRAULIC COOLING MOTOR
The hydraulic motor is fed by a separate pump locatedon the hydraulic pump driven by the engine, the flowenters in the inlet port of the gear motor, the flow forcesthe pinions to turn, the top pinion rotates clock wise andthe lower pinion rotates counter clock wise.
The outlet flow is routed back to the return filter and tothe main return.
Cooling motor
A solenoid (2) is mounted onto the fan motor and isacting like a thermostat, it increases or decreases theRPM of the motor depending on the hydraulic oiltemperature of the circuit.
The over flow is routed back to the tank via the port (1).
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Cooling solenoid
When the engine is running, the controller energizes thesolenoid (1) and keeps the valve (5) open to releasesome flow to the tank line via the port T.
The other part of the flow is routed to the cooling motorvia the port P.
The solenoid (1) energized lifts the piston (2) as well asthe needle valve (3), the chambre (4) is no longer underpressure.
The piston (5) is lifted up without resistance and routessome flow from the P chanel to the T chanel.
The fan motor runs at a lower speed. In fact the solenoidvalve (1) works like an electric relief valve.
When the oil reaches 70C, the temperature sender issending the information to the controller and it will cut the
power off the solenoid (1).
The piston (2) closes the needle valve (3) on its seat, thechamber (4) is kept under pressure and closes the piston(5).
At this time, the total amound of oil is used to run thehydraulic motor and increases the cooling capacity.
The pressure setting is 70 bar, adjusting the top screwmay cause a lack of cooling!
The adjustment of this kind of valve is factory set.
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16. PILOT OIL FEEDING BLOCK
Legend
1 Accumulator 4 Front aux solenoid (red)
2 Pilot supply solenoid (green) 5 Front aux solenoid (blue)
3 Two speed solenoid (yellow) 6 Pressure reducing valve
This control block activates or deactivates the oil pressure fromdifferent functions as above mentioned.
The wires on the solenoids have a coloured strap which corresponds tothe colour straps on colour to the machine wiring.
Accumulator
Used in the pilot pressure circuit. The accumulator gives the operatorthe possibility to put the digging equippment on the ground in case ofan engine shutdown.
The accumulator consists of a nitrogen chambre on top (yellow), adiaphragm in synthetic material and a pressure chambre on the bottom(red).
When the inlet is fed with oil, the nitrogen chambre is compressed tohave a reserve of energy. The accumulator also kills the hydraulic
pump pulses for a good controllability of the joysticks.
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17. SOLENOID VALVE
Four solenoids are used to operate the auxiliaries, the secondspeed and the pilot cut off.
The auxiliary solenoid is operated with a progressive system calledPWM. (pulse width modulation).
When the coil is not energized, the internal spool closes the pilotoil (yellow) passage.
The internal pilot oil is released to the drain channel (green) andfree to tank.
As soon as the solenoid is energized, the internal spool movesdown to close the drain chanel (green) and opens the pilot oilsupply (yellow) that oil is sent to the main spool valve to operatethe corresponding spool.
The pilot cancellation solenoid has a variable pilot pressuredepending the engine RPM, this to prevent stalling the engine.
When taking the pilot pressure, always disconnect the engine RPMsender to make the test.
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18. PRESSURE REDUCING VALVE
With the engine stopped, the spring force will keep the internalspool open until the engine is running, the pump flow will feed theinternal channel (red) with oil.
When the pilot pressure (30 bar) is reached, the hydraulic force willlift the internal spool to close the passage.
Red: circuit pressureYellow: pilot pressureGreen: drain oil
If for any reasons there is a peak pressure in the pilot block, theinternal spool lifts a little more to eliminate the over pressure to thedrain line.
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19. JOYSTICK
A joystick is a hydraulic remote control which operate as apressure reducing valve.
When not actuated the control lever is held in its neutralposition by the four return spring (3). The control ports areconnected to the tank port (T-green) via the drilled holes (5).
When the lever (1) is moved out of neutral, the plunger (2)pushes against the return spring (3) and the control spring (4).The control spring (4) first moves the control spool (6)downwards and closes the connection between theappropriate port and the tank port (T-green).
At the same time the appropriate port is connected to the inletport (P-yellow) via the drilled chanel (5).
The control phase begins as soon as the control spool (6) hasfound its balance between the force of the control spring (4)and the force which results from the hydraulic pressure in theappropriate port.
Through the interaction of the control spool (6) and the controlspring (4) the pressure in the appropriate ports in proportionalwith the stroke of the plunger (2) and thus the position of thecontrol lever (1).
A similar joystick is used to operate the travel, but the controllever is replaced by a longer lever and solid linkages.
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20. DIRECT TO TANK VALVE
Using a hydraulic breaker
The port A, which is the return from the auxiliaries is routedto the port B and from there directly to the main return line.
Using an auger (reversible attachment)
The spool is shifted to the left and the flow from the port A isnow returned to the main spool valve.
This position allows to use an auger in both directions, left orright rotation.
21. CYLINDER
Legend
1 Bushings 8 Cylinder rod
2 Inlet fitting (base end) 9 Inlet fitting (rod end)
3 Piston nut 10 O-ring and back-up seal
4 Cylinder housing 11 Cylinder head
5 Square seal 12 Seal V-type
6 O-ring 13 Scraper seal
7 Piston
All cylinders on the excavator are the same design, just the length and diametres are different.
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22. PRESSURE AND FLOW TEST
Pilot pressure test
Connect a pressure gauge (50 bar) onto thediagnostic coupler located on the port block.
Start the engine and warm up the hydraulic oil until itreaches 50 to 60C and make some mouvements tofill the accumulator.
The pressure on the gauge should be 30 bar.
If the pressure is not correct, adjust the pressurereducing valve located on the same port block.
Circuit pressure check
Connect a pressure gauge (300 bar) onto thediagnostic coupler located on the right end side ofthe spool valve and below the inlet section.
Start the engine and warm up the oil until it reaches50 to 60C.
Use one of the digging equippment (boom forexample), dead end the lift cylinder.
The reading on the gauge should be 240 bar.
If the reading is not correct, adjust this valve (seearrow).
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Port relief valves
The most port relief valves are set at 270 bar andcan be checked with an hand pump, but can not beadjusted.
See the mini excavator specifications for moredetails.
Flow test
Disconnect the hose on the P1 port and plug off thehose.
Use the hydraulic tester 6558197.
Connect the inlet hose from the flow tester to the P1port.
The other end of the hose to the flow tester, thereturn hose of the flow tester directly in to the tank(below the oil level) this to avoid cavitation.
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Restrictor Flow tester Pressure gauge
With the restrictor fully open, start the engine at its maximum RPM (2600). The free flow should be 38 L/min,then screw in the restrictor until the pressure reaches 200 bar. The reading should be at least 80% of theflow.
Note: Do not increase the pressure over 240 bar, there is no relief in the circuit during the test!
Do the same test for P2 and P3.
P1 and P2 38 L/minP3 29 L/min
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HYDRAULICS
WITH HYDROSTATIC TRANSMISSION
430 S/N 562711001 & above
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Table of Contents
1. Hydraulic/hydrostatic schematic ................. .................... ................... .................... ..2-5
2. Component layout....................................................................................................2-7
3. Basic close loop circuit .................... ................... .................... .................... .............2-8
4. Hydrostatic pump.....................................................................................................2-9
5. Replenishing/relief valve........................................................................................2-11
6. Basic drive motor circuit.........................................................................................2-12
7. Drive motor cutaway ................... ................... ................... ................... ..................2-15
8. Spool valve layout..................................................................................................2-16
9. Basic spool valve circuit.........................................................................................2-17
10.Inlet section-view .................. .................... .................... ................... .................... ..2-20
11.Digging section-view..............................................................................................2-21
12.Port/anti-cavitation valve........................................................................................2-22
13.
Main relief valve.....................................................................................................2-23
14.Pilot control block ................... ................... ................... ................... ................... ...2-24
15.Check flow and pressure ................. ................... ................... ................... .............2-25
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1. HYDRAULIC/HYDROSTATIC SCHEMATIC
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Legend
1 Hydrostatic pumps 21 Two speed solenoid
2 Cooling pump 22 Front auxiliary, male coupler
3 Hydraulic pump 23 Front auxiliary, female coupler
4 Drive joystick 24 Swing spool section5 Cooling motor 25 Blade spool section
6 Charge oil filter 26 Boost spool section
7 Right drive motor 27 Auxiliary spool section
8 Left drive motor 28 Bucket spool section
9 Blade cylinders 29 Dipper spool section
10 Centre post 30 Boom spool section
11 Hydraulic reservoir 31 Offset spool section
12 Drain filter 32 Second auxiliary block (optional)
13 Pilot oil drain filter 33 Second auxiliary lines (optional)
14 Hydraulic oil cooler 34 Offset cylinder
15 Right joystick 35 Boom cylinder
16 Left joystick 36 Dipper cylinder
17 Converter valve ISO/STD 37 Bucket cylinder
18 Pressure reducing valve 38 Front auxiliary lines
19 Work group lockout solenoid 39 Direct to tank valve
20 Travel pilot solenoid 40 Swing motor
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2. COMPONENT LAYOUT
Legend
1 Hydraulic reservoir 8 Cooling and pilot oil pump
2 Spool valve 9 Hydrostatic pump
3 Water reservoir 10 Pilot control block
4 Hydraulic filter 11 Hydraulic pump, gear type
5 Hydraulic cooler 12 Variable piston pump
6 Water radiator 13 Direct to tank valve
7 Drain filter 14 Drain filter
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3. BASIC CLOSE LOOP CIRCUIT
Neutral position, engine running
In the neutral position, the hydrostatic pump (1) does not deliver flow to the drive motor (5). The chargepump (2) keeps the close loop circuit under charge pressure due to the charge relief valve (4). Thereplenishing valves (3) are kept open.
Driving forward
The travel lever is shifted in forward motion, the hydrostatic pump (1) supplies oil to the drive motor (5).Thereplenishing valve (3), pressure side is closed. The flushing valve (6) is shifted to remove some flow out ofthe return loop to be cooled.
The charge pump (2) supplies oil to the low pressure side, the replenishing valve (3) at low pressure side iskept open.
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Driving backwards
The travel lever is shifted in rear motion, the hydrostatic pump (1) supplies oil to the drive motor in the
opposite way (5).The replenishing valve (3) at the pressure side is closed. The flushing valve (6) is shifted toremove some flow out of the return loop to be cooled.
The charge pump (2) supplies oil to the low pressure side, the replenishing valve (3) at the low pressure sideis kept open.
4. HYDROSTATIC PUMP
1 2 3
The hydrostatic pump is an axial piston type that is operated with a swash plate by a servo piston.
1. The pump is in the neutral position, the barrel rotates but does not supply oil, the outlets are kept undercharge pressure (yellow).
2. The swash plate is shifted in the forward motion, the pistons supplies oil (red) to the drive motor.
The return oil from the motor is send back to the hydrostatic pump (yellow) and is kept under chargepressure.
3. Same as above but in reverse mode.
The swash plate can take an angle of 18 degrees in forward and reverse.
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Hydrostatic pump cutaway
The hydrostatic pump unit consists of two hydrostatic pumps, mounted in tandem. They are indefinitelyvariable and reversible by servos. Inside the two pumps are located four replenishing/relief valves and twocharge relief valve. The internal channel replenishes the two pumps, the outlet ports (5 and 6) are routed tothe drive motors.
Functions
The pump shaft (7) rotates in one direction and requires a change of internal ports (5 and 6) to change to theopposite rotation of the drive motor. The motor shaft rotates in two directions. With a hydrostatictransmission, machine control can be achieved by a joystick, which provides smooth, step less speed anddirection changes. Placing the joystick in neutral (O swash plate angle n 2) stops the transmission andmotor output which usually eliminates the need for a clutching system.
Charge system
A fixed displacement gear pump is integrated into the variable displacement pump.(not shown) The chargepump supplies oil to the system, keeping the system charged. Charge pressure is limited by a relief valve inthe pump.
The combination replenishing/relief valve is mounted for overload protection and is located in the main pumphousing. These replenishing/relief valves are set at the factory.
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5. REPLENISHING/RELIEF VALVE
In the neutral position of the travel lever, thereplenishing/relief valve is kept open due to the chargepressure.
It replenishes the hydrostatic transmission and keeps itat low pressure.
High pressure channel
When one of the travel levers is shifted in forwardmotion, the replenishing/relief valve closes due to thehigh pressure in the close loop system (red).
As soon as the maximum pressure is reached, thereplenishing valve stays closed, the internal spoolmoves to the right to send the flow back to the chargechanel (yellow).
Charge pressure
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6. BASIC DRIVE MOTOR CIRCUIT
Drive system in the neutral position
Legend
1 Second speed solenoid 9 Drive motor
2 Drive solenoid 10 Second speed spool
3 Brake solenoid 11 Swash plate piston
4 Drive joystick 12 Brake system
5 Brake spool 13 Reduction gear box
6 Selector valve 14 Charge/pilot oil
7 Hydrostatic pump 15 Pump servos piston
8 Flushing valve
The solenoids 1, 2 and 3 are closed, the pilot oil is blocked. The joystick is also in the neutral, if one of thetravel levers is moved there will be no pilot oil to feed the servo piston. The charge pressure will keep the
close loop under low pressure (30 bar) fed by a separate pump (not shown). The brake (12) in the drivemotor remains closed due to the spring action and the drive motor swash plate is kept at the maximum angleor displacement.
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Drive motor in low speed mode
Legend
1 Second speed solenoid 9 Drive motor
2 Drive solenoid 10 Second speed spool3 Brake solenoid 11 Swash plate piston
4 Drive joystick 12 Brake system
5 Brake spool 13 Reduction gear box
6 Selector valve 14 Charge/pilot oil
7 Hydrostatic pump 15 Pump servos piston
8 Flushing valve
The engine is running, the solenoids 2 and 3 are energized this to feed the control lever (joystick 4). Whenone of the control levers is shifted, the pilot pressure is routed to the pump swash plate piston (15), the pump(7) start to deliver flow. At the same time, the spool (5) located in the joystick is shifted with the selector valve(6), the pilot oil (14) is then routed to release the brake system (12) and the motor (9) start to turn. The
flushing valve (8) is also operational at that time.
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Drive motor in the high speed mode
Legend
1 Second speed solenoid 9 Drive motor
2 Drive solenoid 10 Second speed spool3 Brake solenoid 11 Swash plate piston
4 Drive joystick 12 Brake system
5 Brake spool 13 Reduction gear box
6 Selector valve 14 Charge/pilot oil
7 Hydrostatic pump 15 Pump servos piston
8 Flushing valve
The drive motor (9) is still running (see previous page).
The second speed solenoid (1) is energized, the oil is then routed to the second speed spool (10) located inthe travel motor (9). The pump flow (7) is routed to the drive motor (9) but also to the selector valve (6) and
then through the spool (10) and finally to the cylinder (11). This will destroke the swash plate to its minimumdisplacement thus the motor is in high speed mode.
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7. DRIVE MOTOR CUTAWAY
This motor is an axial piston swash plate type. The front part consist of a planetary gear box which islubricated with 90W gear oil, two tapered bearings preloaded with a large nut and two face seals. The midsection has brake discs mechanically applied by means of springs, a barrel unit with its wear plate andswash plate. The swash plate can take two possible positions, maximum swash angle for a low speed andminimum swash angle for high speed.
The rear cover has several components such as a brake spool, a brake selector valve, an over center valve
with check valves and a second speed spool and piston. The connecting ports (A & B) are used to driveforward and reverse. XB is used to destroke the brake discs. XA is where we select high or low speed and Ta drain port.
The brake and the second speed are controlled by two solenoids located in the pilot control block.
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8. SPOOL VALVE LAYOUT
Hydraulic pump P1 29 L/min
P2 29 L/min
P3 33 L/min
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9. BASIC SPOOL VALVE CIRCUIT
All spools in the neutral position
Swing Blade Boost Lift
All spools are in the neutral position; the flow from P3 feeds the inlet at the swing spool section, through theopen center until it reaches the blade and the boost spool. P3 is then routed to the join the flow from P2. Thecombination of the two pumps will feed other functions such as the auxiliaries, the bucket and dipper (notshown).
Swing spool shifted
The swing spool is shifted, the flow from P3 is routed through the load check valve, the spool and then to theswing motor. The return of the swing motor is then routed to the swing spool section and routed to the next
spool to operate the blade cylinders.
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Lift and boost spool shifted
When the lift cylinder is used to lift the boom arm, two spools are used at the same time, the boom spoolsection and the boost spool section.
A combination of two pumps P1 and P3 is used until a pressure of 160 bar. Then the port relief on the boostspool section opens to cancel the pump P3. The check valve closes so that the maximum pressure can beused to lift the boom arm with 195 bar from pump P1.
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10. INLET SECTION-VIEW
The swing section is a series design and serves as an inlet section this due to the special fitting (1). Thespool is in the neutral position; the pump flow enters in the fitting (1) and then routes the flow through theopen center. The flow is then routed through different spool sections until it reaches the outlet port.
The ports A and B are closed; the spool (3) is kept in the center due to the springs (4).
The inlet fitting (1) and the plug (5) have seals (6) to seal the high pressure channel from the low pressurechannel. If one of those seals (6) is damaged, the excavator will have a lack of power.
The spool (3) is shifted to the left, the open center closes. The pump flow is routed to the load check valve,the load check valve opens and the flow is then routed to the port A. It feeds the swing motor; the return flowis then routed back to the port B of the spool section. The return oil from that section is available for the nextfunctions.
Note: The swing section is the only one in series, the others are parallel design.
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11. DIGGING SECTION-VIEW
The spool is in the neutral position. The pump flow is routed through the open center until it reaches theoutlet port. The ports A and B can be open or closed, used by a motor or a cylinder. Some sections have arelief valve (2) or a plug.
The spool (1) can be shifted with pilot oil by means off a joystick or manually with a cable.
The spool (1) is shifted to the left, the open center closes. The pump flow is routed to the load check valve,
opens the load check valve and feeds the port B which is connected to one of the cylinders. The return of itis routed to the spool valve in port A and then to the tank line.
The port relief (2) takes the peak pressures out of the circuit to prevent hoses bursting or cylinder gettingdamaged.
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12. PORT/ANTI-CAVITATION VALVE
The port relief valve is in the closed position; the outletport (red) is connected to one of the digging equipment.
The internal channel (blue) is routed to the main return.
As soon as a peak pressure appears the internal needlemoves to the right and opens to release the some flow tothe main return line.
In case of cavitations, the relief valve will move to the left
and opens and the return flow feeds the needed flow tothe corresponding digging cylinder.
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13. MAIN RELIEF VALVE
Legend
1 Adjusting screw 4 Special washer
2 Spring cup 5 Valve seat
3 Spring 6 Needle valve
Direct operated relief valve
Three relief valves are used in the spool valve and used as main relief valves. The needle valve (6) has alarger surface on the bottom so that the needle valve lifts up when the maximum pressure is reached. Thefree play on the bottom allows oil to enter in the lower chamber and guide the valve when opening.
A special washer (4) is installed to assist the valve when opening, the washer is hollow on one side, so donot mount the washer in the wrong way. Then it could increase the speed of the flow and also the oiltemperature.
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14. PILOT CONTROL BLOCK
Legend
P Pilot pressure entry 1 Solenoid (green)
T Oil back to the tank 2 Solenoid (orange)
B Pilot oil cut off 3 Solenoid (yellow)
C Drive levers cut off 4 Solenoid (blue)
D Two speed cut off 5 Solenoid (red)
E To auxiliary male couplerF To auxiliary female coupler
G1 Diagnostic coupler
A Accumulator
R Pressure reducing valve
This control block activates or activates the pilot pressure from different functions as above mentioned.
The wires on the solenoids have a colored strap which corresponds to the color straps on color to themachine wiring.
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15. CHECK FLOW AND PRESSURE
Pilot pressure test
Connect a pressure gauge onto the diagnosticcoupler on the port block.
Run the engine and warm up the hydraulic oil until itreaches 50 to 60C and make some movements tofill the accumulator.
The pressure reading must be 30 bar.
P1 P2 P3Pump pressure test
All pressure testing shall be done with an oiltemperature between 50 and 60C.
Gear pump:
Connect a pressure gauge (350 bar) onto thediagnostic coupler (P3)
Lift the blade until the end of stroke, the reading onthe gauge should be 265 bar.
Piston pump:
Connect a pressure gauge (350 bar) onto thediagnostic coupler (P1).
Dead end the offset cylinder, the reading on thegauge should be 195 bar.
Connect a pressure gauge (350 bar) onto thediagnostic coupler (P2).
Dead end the bucket cylinder, the reading should be175 bar.
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Flow test
Run the engine and warm up the hydraulic oil until itreaches 50 to 60 C.
Stop the engine and remove the hydraulic filler cap,
this to remove the hydraulic tank pressure.
Each outlet (P1, P2 and P3) must be testedseparately.
Take off the hose on P1 port and plug it off.
Connect the inlet hose from the flow meter to the P1port. (Outlet from the pump.)
Put the return hose from the flow meter into the tank,below the oil level to avoid cavitations during thetest.
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Restrictor Hydraulic tester Pressure gauge
The hydraulic tester 6598439 is difficult to use because of the low volume of oil coming out the hydraulicpumps, use a lower scale tester to have a better reading.
With the restrictor fully open, start the engine at its maximum RPM. The free flow should be 28,8 L/min, thenscrew in the restrictor until the pressure reaches 200 bar. The reading should be at least 80 % of the flow.
Note: Do not increase the pressure over 200 bar, there is no relief valve in the circuit during thetest!
After testing the three outlet ports (P1, P2 and P3) we should have:
P1 and P2: 28,8 L/minP3: 33,3 L/min
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Table of Contents
1. Electric symbols.......................................................................................................3-5
2. Fuse and relay box ..................................................................................................3-8
3. Bobcatdisplay and controller ................. ................... .................... ................... ......3-9
4. Electric block diagram............................................................................................3-10
5. Bobcat excavator controller..................................................................................3-11
6. Diagnostic service code.........................................................................................3-13
7. Keyless controller ..................................................................................................3-14
8. Solenoid valve .......................................................................................................3-15
9. Engine speed sensor ................... .................... .................... ................... ...............3-15
10.Engine and hydraulic temperature sender .............................................................3-16
11.Engine oil pressure sender ................. ................... ................... ................... ..........3-16
12.Fuel stop solenoid..................................................................................................3-16
13.
Fuel level sensor....................................................................................................3-17
14.Cooling motor ........................................................................................................3-17
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1. ELECTRIC SYMBOLS
Alternator
Starter
Cooling fan
Fuse
12
4
Timer
Sender
(normally closed)
Sender
(normally open)
Temperature sender
Battery
Solenoid
Lock solenoid
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Light
Relay
Diode
Ignition switch
Hourmeter
Light switch
Engine solenoid
Seat sensor
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Horn/back up alarm
Two speed switch
Wire number Wire color Wire function
1000-1999 red, red / white, orange power wires
2000-2999 black ground
3000-3999 light blue monitoring
4000-4999 light green hydraulic
5000-5999 yellow attachment control
6000-6999 pink lights
7000-7999 white accessories
8000-8999 tan engine
9000-9999 purple communication
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2. FUSE AND RELAY BOX
1
21
9
17
2
3
4
5
6
7
8
18
19
20
10
11 13 15
12 14 16
Legend
1 Not used 12 Light relay
2 Heater 25A 13 Not used
3 Ignition 5A 14 Glow plug relay
4 Fuel solenoid 25A 15 Switch not used
5 Wiper 5A 16 Starter relay
6 Switch power 20A 17 Controller 25A
7 Alternator/heater 25A 18 ACD 25A
8 ACD 25A 19 Lights 20A
9 Switch power relay 20 Acc plug 15A
10 Fuel solenoid relay 21 Engine harness
11 Not used
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3. BOBCAT
DISPLAY AND CONTROLLER
Sensors
Fuel level
Speed
Engine oil pressure
Engine coolant temperature
Hydraulic temperature
Hydraulic filter condition
Console position Hall effect
Hydraulic charge pressure
Load moment (optional)
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4. ELECTRIC BLOCK DIAGRAM
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5. BOBCAT
EXCAVATOR CONTROLLER
325, 328, 331, 334, 337 & 341 (D & G Series)
Connector J1 Connector J2 Connector J3
A starter relay A front rod A fuel sensorB fuel hold B front base B engine coolant temperature
C light relay C spare solenoid C hydraulic temperature
D open D spare relay D console sensor
E unswitched battery in E 2 speed out E spare analog
F open F spare keyless out F LH pot
G open G diverter G +8V sensor pwr
H glow plug relay H workgroup lockout H GND
J fuel pull relay J piezo buzzer
K sw batt acc relay K load moment
Connector J4 Connector J5 Connector J6
A hall engine speed A can LO A spare analog 2
B glow plug status B can HI B spare digital 1
C fuel pull status C RH ski up C spare digital 2
D starter status D RH ski down D open
E ignition key E two speed E open
F hydraulic filter F RH pot F open
G engine oil pressure G detent
H travel pedal H LH ski down
J crank J LH ski up
K VR engine speed K can shield
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430 & 435 (G Series)
Connector J1 Connector J2 Connector J3
A starter relay A auxiliary male coupler A fuel sensor
B fuel hold B auxiliary female coupler B engine coolant temperature
C light relay C PMW work group C hydraulic temperature
D ground D unused D console sensor
E battery E 2 speed PMW E hydraulic charge signal
F battery F unused F LH pot signal
G ground G unused G +8V sensor power
H glow plug relay H unused H sensor ground
J fuel pull relay J piezo out
K switched power relay K load moment
Connector J4 Connector J5 Connector J6
A hall engine speed A can LO A unusedB glow plug status B can HI B AC on input
C fuel pull status C RH ski up C spare digital 1
D starter status D RH ski down D travel pilot
E ignition key E two speed E spare digital 2
F hydraulic filter F RH pot signal F unused
G engine oil pressure G detent G unused
H unused H LH ski down H spare analog 2
J crank J LH ski up J cooling fan
K VR engine speed K can shield K unused
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6. DIAGNOSTIC SERVICE CODE
02-16 Hydraulic charge filter not connected 14-02 Fuel shut-off hold solenoid short to battery
02-17 Hydraulic charge filter plugged 14-03 Fuel shut-off hold solenoid short to ground
03-09 Battery voltage low 20-02 Two speed output error ON
03-10 Battery voltage high 20-03 Two speed output error OFF
03-11 Battery voltage extremely high 21-02 Glow plug output error ON
03-14 Battery voltage extremely low 21-03 Glow plug output error OFF
03-22 Battery voltage out of range low 22-02 Starter relay output error ON
04-14 Oil pressure extremely low 22-03 Starter relay output error OFF
04-15 Oil pressure shutdown level 26-02 Front base output error ON
05-09 Hydraulic charge pressure low 26-03 Front base output error OFF
05-14 Hydraulic charge pressure extremely low 27-02 Front rod output error ON
05-15 Hydraulic charge pressure shutdown level 27-03 Front rod output error OFF
05-21 Hydraulic charge pressure out of range high 28-02 Diverter output error ON
05-22 Hydraulic charge pressure out of range low 28-03 Diverter output error OFF
06-10 Engine speed high 30-28 Watch dog failure
06-11 Engine speed extremely high 31-28 Recovery mode failure
06-15 Engine speed shutdown level 35-05 Hydraulic fan solenoid short to battery
06-18 Engine speed out of range high 35-06 Hydraulic fan solenoid short to ground
07-10 Hydraulic oil temperature high 60-21 Sec. aux. thumbswitch out of range high
07-11 Hydraulic oil temperature extremely high 60-22 Sec. aux. thumbswitch out of range low
07-15 Hydraulic oil temperature shutdown level 60-23 Sec. aux. thumbswitch not calibrated
07-21 Hydraulic oil temperature out of range high 62-24 Load moment monitoring in error07-22 Hydraulic oil temperature out of range low 63-05 Work group/travel console sensor
08-10 Engine coolant temperature high 63-06 Work group/travel console sensor
08-11 Engine coolant temperature extremely high 64-05 Switched power/acc. relay short to battery
08-15 Engine coolant temperature shutdown level 64-06 Switched power/acc. relay short to ground
08-21 Engine coolant temperature out of range high 64-07 Switched power/acc. relay open circuit
08-22 Engine coolant temperature out of range low 65-02 Work group/travel lockout solenoid error ON
09-09 Fuel level low 65-03 Work group/travel lockout solenoid error OFF
09-21 Fuel level out of range high 65-04 Work group/travel lock. sol. short to battery
09-22 Fuel level out of range low 65-05 Work group/travel lock. sol. sort to ground
12-21 Primary aux. PWM switch out of range high 65-07 Work group/travel lock. sol. open circuit
12-22 Primary aux. PWM switch out of range low 66-05 Travel solenoid short to battery
12-23 Primary aux. PWM switch not calibrated 66-06 Travel solenoid short to ground
13-05 Fuel shut-off hold solenoid short to battery
13-06 Fuel shut-off hold solenoid short to ground
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7. KEYLESS CONTROLLER
Turning Machine On
Locked
Press Enter codeDisplays display codeEnter codeDisplays hours and icons light up momentarily(Note: if you enter an incorrect code error is displayed)Repeat procedure
Unlocked
Press Enter CodeDisplays hours immediately and icons lights up momentarily
Turning Machine Off
Locked
Press Stop ButtonDisplay counts down then powers offDuring countdown you can press stop again to immediately power off
Unlocked
Press Stop ButtonDisplays unlocked for 10 seconds then powers offThis reminds operator that the machine is not locked
Locking machineWith panel on, press the lock unlock buttonDisplays unlock codeEnter codeUnlock icon lights up on panel
Setting passwords
Panel must be in locked conditionPress and hold the Enter Code button for 3 secondsDisplays code 0Press Enter Code to change from code 0 through code 3
Passwords codes
Code 0 Owner Starts engine and can change passwordsCode 1 User Starts engine onlyCode 2 User Starts engine onlyCode 3 User Starts engine only
Points to remember when using service PC
Always, always, always leave the remote start tool key ON.Remote start key does not operate machine.When installing new controller, password will be set by PC.
When installing controller from another machine, password will not be set manually set password usingkeypad.
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8. SOLENOID VALVE
These solenoids operates the console lockout, the two speed, the auxiliary and the pilot pressurecancellation. Some coils are working with the PWM system to have a progressive function. Use a multi meterto test the coils between the wires:
Two speed solenoid: 8 OhmsLockout solenoid: 8 OhmsAuxiliary male solenoid: 7,2 OhmsAuxiliary female solenoid: 7,2 OhmsPilot pressure cancellation: 7,2 Ohms
If a hydraulic motor is used for cooling, the solenoid located on the motor must have 9 Ohms.
9. ENGINE SPEED SENSOR
Located on the flywheel side, it reads the flywheel starting teeth and sends the RPM information to theBobcat
controller. The sender has a plastic spacer in front of it for assembly, when the engine runs it will
chop off the plastic spacer but the sender can be reused, the gap between the sender and the flywheel is 1,2mm.
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10. ENGINE AND HYDRAULIC TEMPERATURE SENDER
These two senders are similar to each other but thevalues are different.
Use a multi meter and take the values between theinternal pins, the reading should be:
Engine coolant sender: 500 to 3000 Ohms.Hydraulic coolant sender: 538 to 1824 Ohms.
11. ENGINE OIL PRESSURE SENDER
The sender has a voltage range between 0,5 to 7,5Vand depending of the engine RPM.
12. FUEL STOP SOLENOID
Hold coil,red
Pull coil,white
Ground,black
The fuel stop solenoid is mounted onto the engine by means of a linkage or direct onto the engine castingwith the Tier 2 engines. Two coils are mounted inside the solenoid and are controlled by the Bobcat
controller.
To test the coils, use a multi meter and note the values in Ohms.Between the white and black wire we should have 0,26 Ohms.Between the red and black wire we should have 10,9 Ohms.
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13. FUEL LEVEL SENSOR
X
The fuel sensor is a variable resistance operated with a magnetic bushing (X). The magnetic bushing movesup and down along the central tube sensing the fuel level.
Check the resistance between the two terminals of the sensor, we should have 33 to 270 Ohms.
14. COOLING MOTOR
The cooling gear motor is fed by a separate hydraulic pump in the circuit, the full amount of flow is not used
with a cold machine. The solenoid valve is kept more or less open this to divide the flow between the tankline and the motor. When the hydraulic oil is at temperature the solenoid valve closes to force more oil intothe cooling motor and to increase the speed of it.
The solenoid is controlled by the Bobcatcontroller and the temperature sender.
Check the resistance between the two pins on the solenoid, we should have 9 Ohms with an engine stoppedand at 20C.
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SERVICE TRAINING Maintenance
01-2005 4-1
MAINTENANCE
430 S/N 562711001 & above
430 S/N 562911001 & above
430 S/N 563011001 & above
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Table of Contents
1. Component location ................... ................... ................... ................... ................... ..4-5
2. Service schedule ................... ................... .................... ................... .................... ....4-6
3. Maintenance .................. .................... .................... ................... .................... ...........4-7
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1. COMPONENT LOCATION
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2. SERVICE SCHEDULE
Check every x hours
8-10 50 100 250 500 1000
Check the engine oil levelCheck the coolant level
Check the hydraulic oil level
Check the air filter (if needed)
Check the track tension
Grease all pivot points
Check the cab heater filter
Lubricate X-change
Grease the swing circle and pinion
Drain water from the fuel filter
Check the battery cables and electrolyte level
Check the main drive belt
Clean the spark arrestor chamber
Replace the fuel filter
Replace the inline fuel filter
Clean the radiator fins
Replace the engine oil and filter
Replace the main hydraulic filter
Replace the case drain filters (2)
Replace the engine coolant system
Replace the hydraulic oil and filter
Replace the travel motor oil (90 W)
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3. MAINTENANCE
Every 8-10 hours, check the coolant level in therecovery tank and add if needed.
Use propylene glycol coolant (purple color) orBobcatcoolant.
Every 8-10 hours, check the coolant level in theradiator and add if needed.
Use propylene glycol coolant (purple color) orBobcat
coolant.
Every 8-10 hours, check the engine oil level and addif needed.
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Engine oil filler cap.
Use 10W 30 or 15W 40 engine oil.
Every 8-10 hours, check the hydraulic oil level and
add if needed.
Hydraulic oil filler cap.
Use 10W 30 or 15W 40 engine oil.
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Every 8-10 hours, check the air filter condition.
Clean or replace only when required.
Every 8-10 hours, remove the trapped water
(depending the weather condition) at the fuel filter.
Every 8-10 hours, inspect the rubber tracks for wearor damages and the correct tension.
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Every 8-10 hours, check the coolant radiator for dirtdepending on the working condition.
Take off the two nuts to separate the radiators.
Use pressurized air or water to clean the radiators,
this to prevent overheating, loss of performance orengine damage.
Every 8-10 hours, lubricate with multi-purpose lithiumbased grease all pivot points such as dozer bladecylinders, boom, dipper and bucket.
Every 50 hours, lubricate with multi-purpose lithiumbased grease the swing circle and pinion.
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Every 50 hours, drain water and sediment from thefuel tank (depending the weather condition).
A plug is located under the reservoir.
Every 50 hours, check the battery cables,
connections and electrolyte.
Add distilled water if needed.
Every 100 hours, check the accessory V-belt, adjustor replace as needed.
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Every 100 hours, clean the spark chamber.
Every 250 hours, replace the fuel filter.
Use a genuine Bobcatfilter; lubricate the filter seal
before installing.
Replace inline fuel filter located just behind the fuelfilter.
Every 500 hours, flush the engine oil.
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Every 500 hours, replace the fan hydraulic filter.
Use a genuine Bobcatoil filter.
Every 500 hours, replace the case drain filter.
The filter is the same as on the picture above.
Use a genuine Bobcatoil filter.
The filter is located behind the fuel filter.
Every 250 hours, check the tension of the multi V-belt.
The idler has a tension indicator, if the multi V-belt isworn out, it must be replaced by a new one.
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Every 1000 hours, drain and flush the coolingsystem.
Use propylene glycol coolant (purple color) to fill theradiator.
Use the same coolant for the recovery bottle.
Do not mix propylene glycol with ethylene glycol.
Every 1000 hours, replace the oil in the reductiongear box.
Drive the excavator until one of the plug is at thebottom to flush the oil.
The second plug must be horizontal to fill thereduction gear box.
Use 90 W gear oil to fill the reduction gear box.
Every 1000 hours, flush the hydraulic oil with theflushing hose.
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Use 10W 30 or 15W40 to fill the hydraulic reservoir.
Replace the breather cap at the same time.
Fill the hydraulic oil until the correct level is reached.
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SERVICE TRAINING Safety
01-2005 5-1
SAFETY
430 S/N 562711001 & above
430 S/N 562911001 & above
430 S/N 563011001 & above
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1 READ THE OPERATOR MANUAL BEFORE USING THE EXCAVATOR!
2 LIFT THE ARM REST BEFORE LEAVING THE EXCAVATOR!
3 LOWER THE DOZER BLADE BEFORE LEAVING THE EXCAVATOR!
4 PUT THE DIGGING EQUIPMENT ONTO THE GROUND WHEN YOU FINISH A JOB!
5 DO NOT WALK UNDER THE BOOM ARM!
6 DO NOT GRAB THE JOYSTICK TO ENTER THE CAB!
7 DO NEVER CUT OR MODIFY THE CAB STRUCTURE (ROPS AND FOPS CAB)!
8 USE THE GRAB HANDLE TO ENTER THE CAB!
9 KEEP ALL COVERS CLOSED WHEN OPERATING THE EXCAVATOR!
1
2
3
4
5
6
7
8
9
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Never service the Bobcat
excavator without instruction.Use the correct procedure to liftand support the excavator.
Cleaning and maintenance arerequired daily.
Have good ventilation whenwelding or grinding paintedparts.
Wear dust mask when grindingpainted parts.
Toxic dust and gas can beproduced.
Vent exhaust to outside whenengine must be run for service.
Exhaust system must be tightlysealed.
Exhaust fumes can kill withoutwarning.
Always lower the bucket andblade to the ground beforedoing any maintenance.
Never modify equipment or addattachments not approved byBobcat
Company.
Stop, cool and clean engine offlammable materials beforechecking fluids.
Never service or adjust machinewith the engine running unless
instructed to do so in themanual.
Keep body, jewelry and clothingaway from moving parts.
Wear eye protection to guardfrom battery acid.
Lead-acid batteries produceflammable and explosive gases.
Batteries contains acid whichburns eyes or skin on contact.
Wear protective clothing.
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Check that the ROPS/FOPS is ingood condition and is not modified.
Safety treads must be in goodcondition.
Check that ROPS/TOPS mountinghardware is tightened and is Bobcat
approved.
Check for correct function ofindicator lamps (optional on somemodels).
The seat belt must be correctlyinstalled, functional and in goodcondition.
Check hydraulic fluid level, engine oillevel and fuel supply.
Inspect for loose or broken parts orconnections.
Inspect for fuel, oil or hydraulic fluidleaks.
Machine signs must be legible and inthe correct location.
Lubricate the excavator.
Steering levers, control levers andfoot pedals must return to neutral.Check that foot pedals lock andcontrol lever locks are in workingorder.
Check the condition of the batteryand cables.
Inspect the air cleaner for damage orleaks. Check the condition of thefilters.
Recommend to the owner that allnecessary corrections be madebefore the excavator is returned toservice.
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