PDF Service Manual Bobcat 953 Loader - 8 MB
Access the official service manual for the Bobcat 953 Loader and get the same detailed information used by factory-trained technicians.
This guide covers everything from routine maintenance tasks to complex overhaul procedures for all major systems.
With this manual, you can confidently tackle any repair, ensuring your loader operates reliably and efficiently for years to come.
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--- Page 1 ---
9
5
Service
Manual
Dealer Copy -- Not for Resale
Doosan purchased Bobcat Company from Ingersoll-Rand Company in
2007. Any reference to Ingersoll-Rand Company or use of trademarks,
service marks, logos, or other proprietary identifying marks belonging
to Ingersoll-Rand Company in this manual is historical or nominative
in nature, and is not meant to suggest a current affiliation between
3
Ingersoll-Rand Company and Bobcat Company or the products of
either.
EQUIPPED WITH
BOBCAT INTERLOCK
CONTROL SYSTEM (BICSTM) 6724352 (02-20) Printed in U.S.A. © Melroe Company 1995
1 of 344
--- Page 3 ---
SERIAL NUMBER LOCATIONS
Always use the serial number of the loader when
A
requesting service information or when ordering parts.
Early or later models (identification made by serial
number) may use different parts, or it may be necessary
to use a dif ferent procedure in doing a specific service
operation.
LOADER SERIAL NUMBER
The loader serial number plate is located on the inside of
the left upright, above the grill [A].
Explanation of loader Serial Number:
XXXX XXXXX P–3831
Module 2. – Production
Sequence (Series) B
Module 1. – Model/Engine
Version
The four digit Model/Engine Combination module number
identifies the model number and engine combination.
This number (in parenthesis beside the model number) is
used in the Service Manual to more easily identify the
standard, optional and field accessory equipment
included or available for each specific model.
The five digit Production Sequence Number identifies the
order which the loader is produced.
ENGINE SERIAL NUMBER
P–3832
The serial number is located above the starter on the
engine block [B].
DELIVERY REPORT C
The Delivery Report must be filled out by the dealer and
signed by the owner or operator when the Bobcat loader
is delivered. An explanation of the form must be given to
the owner. Make sure it is filled out completely [C].
953 Bobcat Loader
vii Service Manual
--- Page 4 ---
OPERATOR CAB
Description
A
The Bobcat loader has an operator cab (ROPS and
FOPS) as standard equipment to protect the operator
from rollover and falling objects. Check with your dealer
if the operator cab has been damaged. The seat belt must B–7705
be worn for roll over protection.
ROPS/FOPS – Roll Over Protective Structure per SAE
J104 and ISO 3471, and Falling Object Protective
Structure per SAE J1043 and ISO 3449, Level l. Level ll
is available. 1
Level l – Protection from falling bricks, small concrete
blocks and hand tools encountered in operations such as P–3847
highway maintenance, landscaping, and other
construction site services.
Level ll – Protection from falling trees, rocks; for
B
machines involved in site clearing, overhead demolition
or forestry.
Never modify operator cab by welding,
grinding, drilling holes or adding attachments
unless instructed to do so by Melroe Company.
Changes to the cab can cause loss of operator
protection from rollover and falling objects, P–3846
and result in injury or death.
W–2069–1285
C
Raising the Operator Cab
Stop the loader on a level surface. Lower the lift arms. If
the lift arms must be up while raising the operator cab,
install the lift arm support device. (See Page 1–6.)
Before the cab or the lift arms are raised for
P–4537
service, jackstands must be put under the rear
corners of the frame. Failure to use jackstands
may allow the machine totip backward causing
injury or death.
W–2014–1285
Loosen the nut (Item 1)[A] (both sides) at the front corner
of the operator cab.
Remove the nut and plate (both sides) [B].
Lift on the grab handle and bottom of the operator cab
slowly until the cab latching mechanism engages and the
cab is all the way up [C].
953 Bobcat Loader
–1–7– Service Manual
--- Page 5 ---
ENGINE COOLING SYSTEM (Cont’d)
Removing Coolant From the Cooling System
A
1
Do not remove radiator cap when the engine is
hot. You can be seriously burned.
W–2070–1285
Open the rear door. Open the rear grill.
P–4517
Remove the radiator cap (Item 1) [A].
Connect a hose to the engine block drain valve (Item 1)
[B]. Open the drain valve and drain the coolant into a
B
container.
After all the coolant is removed, close the drain valve.
NOTE: Protect the cooling system by adding
premixed coolant to the system. (See Page 1
1–16.) This mixture will protect the cooling
system to –34oF. (–36oC.)
Mix the coolant in a separate container. (See
Specifications for correct capacity, Page 9–1.)
Fill the radiator with the premixed coolant. Install the
radiator cap. P–4516
Fill the coolant recovery tank 1/3 full.
Run the engine until it is at operating temperature. Stop
the engine.
Check the coolant level in the recovery tank when cool.
Add coolant to the recovery tank as needed.
953 Bobcat Loader
–1–17– Service Manual
--- Page 6 ---
REMOTE START SWITCH
Procedure
A
The tool listed will be needed to do the following
procedure:
MEL1429 – Remote Start Switch
1
Put jackstands under the front axles and rear P–6860
corners of the frame before running the engine
for service. Failure to use jackstands can allow
the machine to fall or move and cause injury or
death. B
W–2017–0286
The Remote Start Switch (Item 1)[A] is required when the
operator cab is in the raised position for service and the
service technician needs to start the engine. The operator
cab wire harness connectors must be separated from the 1
engine wiring harness connector under the cab.
The remote start switch is required when the service
technician is adjusting the steering linkage and checking
the hydraulic/hydrostatic system.
Lift and block the loader. (See Page 1–4.)
P–6859
Raise the lift arms and install an approved lift arm support
device. (See Page 1–6.)
Raise the operator cab. (See Page 1–7.)
Connect the remote start switch to these connectors
(Item 1) [B].
953 Bobcat Loader
–1–27– Service Manual
--- Page 7 ---
HYDRAULIC/HYDROSTATIC SCHEMATIC 25 MICRON FILTER 15 17 19
953 BICS (S/N 513111594 - 14999) A
(S/N 513115085 and Above) FEMALE
LH
(Printed February 1997)
(MC-2319)
MALE
18 B 12 14
Printable Version Click Here 20
4 MICRON FILTER
16 TILT CYLINDERS
1 27 CONTROL VALVE
JUNCTION
PORT
BLOCK
2 A4 B4
23
22 AUX. FRONT TILT CYLINDERS
B3 TILT LOCK VALVE
A3 B1
21 REAR
AUXILIARY
CAPPED AT
VALVE AUX. REAR
4
3
11 A2
24
24 B2
10 PP PT X P2
25
5
9 TILT
28
A1
25
B1
6 X PT
P1
7 8 LIFT
28
FAN MOTOR PORT BLOCK
D C
29 L1
3 MICRON FILTER LIFT LOCK VALVE
25
BUCKET
12
POSITION LIFT CYLINDERS
VALVE
13 30
14
33
24 24 B
RH 31
32
A B LIFT CYLINDERS
34 18
HYDROSTATIC PUMP 1 & 2 MC 2319 (1-31-97)
A
--- Page 8 ---
HYDRAULIC CYLINDER REPAIR (Cont’d)
A
Assembly
The tools listed will be needed to do the following
procedure:
MEL1032 – Rod Seal Tool
MEL1009 – Seal Installation Tool (3’’)
Remove the oil seal from the end cap [A].
B–4671
Remove the teflon seal and the O–ring from the piston
[B]. B
Wash all the parts in clean solvent. Dry with air only .
Destroy old seals and O–rings.
Inspect the parts for scratches, nicks, bent, etc. Replace
the parts as needed.
B–3689
B–3703
Install the piston on the tool [C]. C
Install the O–ring on the piston using the tool [C].
B–3674
B–3675
Install the Teflon seal over the tool and on the piston[D].
D
NOTE: To prevent damage to the Teflon seal, do not
turn it into the piston groove.
Install the piston into the tapered end of the tool to get the
Teflon seal to the piston size diameter [D].
Wait 5 minutes so that the T eflon seal will become the
same size as the piston.
B–3677
B–3673
953 Bobcat Loader
–2–11– Service Manual
--- Page 9 ---
HYDRAULIC CONTROL VALVE (Cont’d)
A
Disassembly and Assembly (Cont’d)
Remove the inlet section and O–ring [A].
B–7752
Remove the lift section, O–ring, load check poppet and
spring [B]. B
B–7720
Remove the tilt section, O–ring, load check poppet and
spring [C]. C
B–7775
Remove the rear auxiliary section, O–ring, load check
poppet and spring [D]. D
B–7801
953 Bobcat Loader
–2–21– Service Manual
--- Page 10 ---
CHARGE PUMP (Cont’d)
A
Disassembly and Assembly (Cont’d)
Mark the charge pump housing for correct assembly [A].
B–7904
Loosen the bolts at the pump housing [B].
Assembly: Tighten the bolts to 22–25 ft.–lbs. (30–34
B
Nm) torque.
B–7902
Remove the bolts from the pump [C].
C
B–7903
Remove the pump end housing and O–ring [D].
D
B–7905
953 Bobcat Loader
–2–31– Service Manual
--- Page 11 ---
HYDRAULIC FILTER
A
Removal and Installation
Open the rear door.
Raise the operator cab. (See Page 1–1.)
Disconnect the wire from the sending switch [A].
P–6540
Disconnect the hose [B].
B
P–6541
Disconnect the hose [C].
C
P–6542
Remove the mounting bolts [D].
Remove the filter housing from the loader.
D
P–6543
953 Bobcat Loader
–2–41– Service Manual
--- Page 12 ---
FAN MOTOR
A
Removal and Installation
When making repairs on hydrostatic and
hydraulic systems, clean the work area before
disassembly and keep all parts clean. Always
use caps and plugs on hoses, tubelines and
ports to keep dirt out. Dirt can quickly damage
the system. P–6574
I–2003–0284
B
Remove the hydraulic reservoir. (See Page 2–40.)
Remove the bolt and nut at the tank mounting plate (both
sides) [A].
Remove all the bolts at the front of the shrouding panel
[B].
P–6575
Remove the shrouding panel [C].
C
P–6576
Mark the hoses for correct installation. Disconnect the
inlet and outlet hoses (Items 1 & 2) [D] at the fan motor. D
2 1
P–6577
953 Bobcat Loader
–2–51– Service Manual
--- Page 13 ---
TROUBLESHOOTING
Chart
The following troubleshooting chart is provided for
assistance in locating and correcting problems which are
most common. Many of the recommended procedures
must be done by authorized Bobcat Service Personnel Check for correct function after adjustments,
only. repairs or service. Failure to make correct
repairs or adjustments can cause injury or
death.
W–2004–1285
PROBLEM CAUSE
No drive on one side, in one direction. 1, 2, 3
No drive on one side in either directions. 2, 3, 5, 6, 20, 22
The loader does not move in a straight line. 2, 3, 4, 6, 7, 8, 20
The hydrostatic system is overheating. 9, 10, 11, 12, 13, 14, 17, 18, 19
The oil light comes ON. 11, 14, 15, 16, 21
KEY TO CORRECT THE CAUSE
1. The hydrostatic system has a fluid leak.
2. The steering linkage needs adjustment.
3. The high pressure replenishing valve(s) are defective.
4. The hydrostatic pumps have a defect.
5. The final drive chain is broken.
6. The hydrostatic motor has a defect.
7. The tires do not have the correct tire pressure.
8. The tires are not the same size.
9. The hydrostatic fluid is not at the correct level.
10. The oil cooler has a restriction.
11. The temperature switch is not operating correctly.
12. The control valve is not operating correctly.
13. The loader is not being operated at the correct RPM.
14. The temperature switches have a defect.
15. There is low charge pressure.
16. Filters need replacing.
17. Fan motor by–pass valve has a defect.
18. Fan motor solenoid valve has a defect.
19. Oil cooler by–pass valve has a defect.
20. Tow valves maybe open.
21. Fluid is too hot.
22. Control sleeve orifice is plugged at hydrostatic pumps.
953 Bobcat Loader
–3–3– Service Manual
--- Page 14 ---
HYDROSTATIC MOTOR (Cont’d)
Disassembly and Assembly (Cont’d)
A
Remove the rotating group assembly [A].
B–7458
Remove the wear plate [B].
B
B–7459
Remove the first snap ring [C].
C
Using a seal puller, remove the seal from the housing.
Remove the second snap ring [C].
B–7460
Remove the shaft and bearing assembly [D].
D
B–7461
953 Bobcat Loader
–3–13– Service Manual
--- Page 15 ---
HYDROSTATIC PUMP (Cont’d)
Disassembly and Assembly (Cont’d)
A
Rear Pump:
Remove the bearing and shaft assembly [A].
B–8001
Front Pump: B
Remove the snap ring at the seal [B].
B–8019
Front Pump:
C
Drill a hole in the seal [C].
B–8020
Front Pump:
D
Install a seal puller and remove the seal [D].
B–8056
953 Bobcat Loader
Revised June 96 –3–23– Service Manual
--- Page 16 ---
HYDROSTATIC FILTER (Cont’d)
Disassembly and Assembly
A
1
Loosen the pressure switch (Item 1) [A].
P–6545
Remove the pressure switch [B]. B
P–6546
Case Drain Filter C
The case drain filter (Item 1) [C] must be replaced
whenever there have been major repairs to the
hydrostatic pumps or motors.
1
P–4529
953 Bobcat Loader
Revised June 96 –3–33– Service Manual
--- Page 17 ---
PARKING BRAKE
Removal and Installation
A
Raise the loader operator cab. (See Page 1–1.) 2
Remove the (2) mounting bolts (Item 1)[A] from the brake
pedal mounting bracket.
Installation: Tighten the mounting bolts to 25–28 ft.–lbs.
(34–38 Nm) torque.
Disconnect the electrical connector from the parking
brake pedal sensor (Item 2)[A]. The connector is located 1
behind the control panel.
Remove the parking brake assembly from the loader by P–3843
moving the rubber floor mat and removing the tube clamp
(Item 1) [C] and sliding the tube and wires out.
Reverse the removal procedure to install the parking
B 5
brake assembly in the loader.
6
Disassembly and Assembly
Loosen and remove the mounting bolt (Item 1)[B] and nut
from the spring mounting bracket (Item 2) [B].
1
Remove the brake pedal spring (Item 3) [B] from the
tension spring mounting bracket (Item 2)[B] and from the 4
brake pedal mounting bracket (Item 4) [B].
Remove the (2) mounting bolts, washers and nuts (Item 2
5) [B] from the brake pedal sensor.
3
P–4189
Remove the harness mounting clamp (Item 1) [C] from C
the pedal mounting bracket (Item 4) [B]. 1
Remove the sensor harness form the pedal mounting
bracket.
Remove the pedal Mounting bolt (Item 6) [B], plastic
spacers and bushing nut from the brake pedal.
Remove the pedal from the pedal mounting bracket.
Photo [C] shows the parking brake disassembled to
identify the existing parts in the brake assembly.
P–4156
953 Bobcat Loader
–4–3– Service Manual
--- Page 18 ---
FRONT AXLE AND SPROCKET (Cont’d)
A
Removal (Cont’d)
Pull the bearing cup from the axle tube [A].
B–7686
Use along rod and remove the inner bearing cup [B]
(MEL1202–13). B
B–7687
Using the correct size driver, install the outer bearing cup
[C] (MEL1202–12). C
B–7679
Install the long threaded bolt into the axle tube. Install the
correct size bearing cup driver. Install a washer and nut
[D] (MEL1202–11). D