PDF Service Manual Bobcat 853 853H - 2 MB
This is the official service manual for the Bobcat 853 and 853H skid-steer loaders.
It provides clear, step-by-step instructions for all maintenance and repair tasks.
The manual is filled with diagrams and specifications to guide you through any procedure, from routine service to major overhauls.
Trust this factory manual to help you maintain the legendary performance of your Bobcat loader.
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--- Page 1 ---
8
5 Service
3 Manual
(S/N 508411001–508417999)
(S/N 509711001–509717999)
(S/N 510250001 & Above)
(S/N 510375001 & Above)
(S/N 512815001–512815999)
(S/N 510125001 & Above)
8
(S/N 512311001 & Above)
5
3
H
6720755 (6–99) Printed in U.S.A. © Melroe Company 1999
--- Page 3 ---
SAFETY INSTRUCTIONS
Instructions are necessary before operating or servicing machine. Read and understand the Operation &
Maintenance Manual, Handbook and signs (decals) on machine. Follow warnings and instructions in the
manuals when making repairs, adjustments or servicing. Check for correct function after adjustments,
repairs or service. Untrained operators and failure to follow instructions can cause injury or death.
W–2003–0299
The following publications provide information on the safe use and maintenance of the loader and attachments:
• The Delivery Report is used to assure that complete instructions have been given to the new owner and that the machine
is in safe operating condition.
• The Operation & Maintenance Manual delivered with the loader gives operating information as well as routine
maintenance and service procedures. It is a part of the loader and must stay with the machine when it is sold. Replacement
Operation & Maintenance Manuals can be ordered from your Bobcat loader dealer.
• The loader has machine signs (decals) which instruct on the safe operation and care. The signs and their locations are
shown in the Operation & Maintenance Manual. Replacement signs are available from your Bobcat loader dealer.
• The loader has a plastic Operator’s Handbook fastened to the operator cab. Its brief instructions are convenient to the
operator. The Handbook is available from your dealer in an English edition or one of many other languages. See your
Bobcat dealer for more information on translated versions.
• The EMI Safety Manual (available in Spanish) delivered with the loader gives general safety information.
• The Service Manual and Parts Manual are available from your dealer for use by mechanics to do shop–type service and
repair work.
• The Skid–Steer Loader Operator Training Course is available through your local dealer. This course is intended to provide
rules and practices for correct operation of the Bobcat loader. The course is available in English and Spanish version.
• The Service Safety Training Course is available from your Bobcat dealer. This course provides information for safe and
correct service procedures for Bobcat Skid–Steer loaders.
• The Bobcat Skid–Steer Loader Safety Video is available from your Bobcat Dealer.
Warnings on the machine and in the This notice identifies procedures
manuals are for your safety. Failure to which must be followed to avoid
obey warnings can cause injury or damage to the machine.
death. I–2019–0284
W–2044–1285
Safety Alert Symbol: This symbol with a warning statement, means: “Warning, be alert! Your safety is
involved!” Carefully read the message that follows.
SI05–0299
853, 853H Loader
v Service Manual
--- Page 4 ---
LIFT ARM SUPPORT DEVICE
A
1
Never work on a machine with the lift arms up 2
unless the lift arms are secured by a lift arm
support device. Failure to use an approved lift
arm support device can allow the lift arms or
attachment to fall and cause injury or death.
W–2059–0991
P–02133
Engaging the Lift Arm Support Device
Maintenance and service work can be done with the lift
arms lowered. B
If the lift arms must be raised for service, use the following
procedure:
Put jackstands under the rear corners of the loader.
Disconnect the spring (Item 1) [A] from the lift arm 1
support device retaining pin (Item 2) [A]. Hold onto the lift
arm support device and remove the retaining pin.
Lower the lift arm support device on top of the lift cylinder.
Hook the free end of the spring (Item 1) [B] to the lift arm
support device so there will be no interference with the
support device engagement. P–02118
With the operator in the seat, seat belt fastened and seat
bar lowered, start the engine.
C
Raise the lift arms, until the lift arm support device drops
onto the lift cylinder rod [C].
Lower the lift arms slowly until the support device is held
between the lift arm and the lift cylinder. Stop the engine.
Raise the seat and move pedals until both pedals lock.
Install pin (Item 1) [C] into the rear of the lift arm support
device below the cylinder rod.
1
P–00095
Service lift arm support device if damaged or if
parts are missing. Using a damaged lift arm
support or with missing parts can cause lift
arms to drop causing injury or death.
W–2271–1197
853, 853H Loader
–1–7– Service Manual
--- Page 5 ---
ENGINE LUBRICATION SYSTEM (Cont’d)
Replacing Oil And Filter (Cont’d)
A
Remove the oil filler cap (Item 1) [A].
Put 8 qts. (7,6 L) of oil in the engine. (See Oil Chart, Page
1–16.)
Start the engine and let it run for several minutes. Stop the
engine. Check for leaks at the oil filter. Add oil as needed
if it is not at the top mark on the dipstick.
1
CD–15114
Always clean up spilled fuel or oil. Keep heat,
flames, sparks or lighted tobacco away from
fuel and oil. Failure to use care around
combustibles can cause explosion or fire
which can result in injury or death.
W–2103–1285
853, 853H Loader
–1–17– Service Manual
--- Page 6 ---
LUBRICATING THE LOADER
Procedure
A
Lubricate the loader as specified in the SERVICE
SCHEDULE, Page 1–3 for the best performance of the
loader.
Record the operating hours each time you lubricate the
Bobcat loader.
1
Always use a good quality lithium based multi–purpose
grease when you lubricate the loader. Apply the lubricant
until extra grease shows.
Lubricate the following locations on the loader:
CD–15169
1. Rod End Lift Cylinder (Both Sides) [A].
2. Base End Lift Cylinder (Both Sides) [B].
B
2
CD–15171
3. Lift Arm Pivot Pin (Both Sides) [C].
C
3
CD–15170
4. Base End Tilt Cylinder [D].
D
4
CD–15168
853, 853H Loader
–1–27– Service Manual
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HYDRAULIC/HYDROSTATIC SCHEMATIC
853 (S/N 508415216-17999)
(S/N 510126792 AND ABOVE)
(S/N 510250692 AND ABOVE)
(S/N 512811001-15999)
(Printed June 1999)
MC2397LU
LEGEND
1 RESERVOIR: 13 RELIEF VALVE - PORT: 24 FILTER 38 FIXED CAPACITY DISPLACEMENT
C apacity . . . 15.5 Qts (14,7 L) 3500 PSI (24132 kPa) BIDIRECTIONAL HYDROSTATIC
25 RELIEF VALVE - CHARGE: MOTOR
2 SPRING LOADED FILTER BYPASS 14 LOAD CHECK VALVE 140°F. (60°C.) F luid at Full RPM
VALVE: 45-55 PSI (311-379 kPa) 39 ANTICAVITATION VALVE
15 ONE WAY RESTRICTOR VALVE Neutral . . . . 310-330 PSI
3 DIFFERENTIAL PRESSURE SWITCH: (2137-2275 kPa )
36-44 PSI (248-303 kPa) 16 RELIEF VALVE - MAIN: Stroked . . . . 3O0-320 PSI
853 PLUS - Normally Closed 2550-2600 PSI (17582-17927 kPa) (2069-2206 kPa)
853 BASE - N ormally Closed at Front Quick Couplers
26 MUFFLER (If Equipped)
4 CHECK VALVE - FILTER 17 SHUTTLE RELIEF VALVE:
225-290 PSI (1551-2000 kPa ) 27 CHARGE PRESSURE SENSOR
5 FLOW DIVIDER ADJUSTMENT VALVE
18 DRIVE MOTOR SHUTTLE VALVE
28 FLUID TEMPERATURE SENSOR
6 PILOT ACTIVATED DIRECTIONAL
19 TOW VALVE
CONTROL VALVE - FLOW CONTROL 29 PILOT ACTIVATED DIRECTIONAL
SPOOL 20 RELIEF/REPLENISHING VALVE - HIGH CONTROL VALVE - FOR REAR
7 PILOT ACTIVATED DIRECTIONAL PRESSURE: AUXILIARY - NORMALLY OPEN
CONTROL VALVE - UNLOADING STANDARD . 4350 PSI (29990 kPa) ("D1")
SPOOL OPTIONAL . 5000 PSI (34475 kPa) 30 SOLENOID ACTIVATED DIRECTIONAL
8 PILOT ACTIVATED DIRECTIONAL 21 DISPLACEMENT CONTROL VALVE CONTROL VALVE - FRONT
CONTROL VALVE - FOR REAR AUXILIARY (OPTIONAL ON 853 BASE)
22 CHARGE PUMP . . . . 11.0 GPM
AUXILIARY - NORMALLY OPEN 31 PILOT ACTIVATED DIRECTIONAL
(41,6 L./M in .) at 2850 RPM
("D2") CONTROL VALVE - FOR REAR
23 HYDRAULIC PUMP AUXILIARY - NORMALLY CLOSED
9 RELIEF VALVE - PORT: (OPTIONAL)
3100 PSI (21371 kPa) 18.0 GPM (68,1 L/min.) ("P1" and "F1")
10 SOLENOID ACTIVATED DIRECTIONAL at 2750 RPM 32 FILTER
CONTROL VALVE - AUXILIARY
33 SOLENOID ACTIVATED DIRECTIONAL
(OPTIONAL)
CONTROL VALVE
11 CHECK VALVE - BUCKET POSITION
VALVE 34 FILTER - HYDROSTATIC (CANISTER)
12 RELIEF/ANTICAVITATION VALVE - 35 PILOT ACTIVATED DIRECTIONAL
PORT (TILT BASE END): CONTROL VALVE - FOR REAR
AUXILIARY - NORMALLY CLOSED NOTE: Unless otherwise specified,
2500 PSI (17238 kPa)
("P2" and "F2") springs have NO significant
pressure value.
36 FILTER - HYDRAULIC (CANISTER)
37 FILTER
Printed in U.S.A.
--- Page 9 ---
FRONT AUXILIARY
FEMALE
MALE
AUXILIARY VALVE (JEM) F1 F2
29 29
32 32 CASE DRAIN
FRONT AUXILIARY
D1
34 FEMALE
33 D2
MALE
31 30
RIGHT DRIVE MOTOR HYDRAULIC
FILTER BUCKET POSITION VALVE (OPTIONAL)
16
17 36
D
5
10
2
3 A
38 4
HYDROSTATIC
C
FILTER
HYDROSTATIC PUMPS 6
10
35
27
28 24
18 7
2
19 B
20
PORT
BLOCK
1
OIL 37 23
COOLER 3 HYDRAULIC
CONTROL
22 VALVE
OUTLET
INLET
21 INLET
OUTLET
8
40
26
9
9 AUXILIARY
SPOOL
25
T1LT CYLINDER
11
20 TILT CYLINDER
SPOOL
19 14
12 13
LIFT CYLINDER
LEFT DRIVE MOTOR
38 LIFT CYLINDER SPOOL
39
13
17 15
16 WORKING CIRCUITS
PILOT PRESSURE
DRAIN CIRCUITS
COMPONENTS
Printed in U.S.A.
MC2399U (5-19-99)
--- Page 10 ---
HYDRAULIC CYLINDERS (Cont’d)
Disassembly
A
Use the following tools to disassemble the cylinder:
MEL1074 – O–ring Seal Hook
Spanner Wrench
The lift and tilt cylinders internal components are similar,
the differences are listed below:
Tilt rod diameter is larger.
Piston relief area is slightly different.
No spacer in the tilt cylinder.
Hold the hydraulic cylinder over a drain pan and move the P–07429
rod in and out slowly to remove the fluid from the cylinder.
Put the base end of the cylinder in a vise. B
Use a spanner wrench to loosen the head [A] & [B].
P–07435
Lift Cylinder: Remove the head and the rod assembly
from the cylinder [C]. Put the rod end in a vise. C 4
3
2
Lift Cylinder: Remove the nut (Item 1) [C], piston (Item 2)
[C], spacer (Item 3) [C] (if so equipped) and head (Item 1
4) [C].
P–07428
Tilt Cylinder: Remove the head and rod assembly from D
the cylinder [D]. Put the rod end in a vise. 2 3
1
Tilt Cylinder: Remove the nut (Item 1) [D], piston (Item 2)
[D] and head (Item 3) [D].
P–07434
853, 853H Loader
–2–15– Service Manual
--- Page 11 ---
DUAL PRESSURE MAIN RELIEF VALVE (S/N
512811001 & Above) W/Select Valve (JEM) (Cont’d) A
Checking The High Setting (Cont’d)
Install the hose (Item 1) [A] on the secondary auxiliary
quick couplers as shown.
NOTE: The hose loop (Item 1) [A] (with .070 inch
orifice), provides restriction and pilot
pressure necessary to shift the dual stage
main relief valve to the high pressure setting.
1
P–05196
When the engine is running during service, the
B
steering levers must be in neutral and the
parking brake engaged. Failure to do so can
cause injury or death.
W–2006–0284
Start the engine and run at low idle RPM. Increase the
engine speed to full RPM. Push the mode switch (Item 1)
[B] twice (on the instrument panel) to engage the front 3
auxiliary hydraulics detent, the lights (Items 2 & 3) [B] will 1
come ON.
NOTE: The High Horsepower switch should be in the
OFF position. 2
P–00998
Push the button (Item 1) [C] to engage the detent position
to the front auxiliary quick couplers.
Push and hold the button (Item 2) [C] for fluid flow through C
the secondary auxiliary couplers and hose loop.
Watch the flow meter on the hydraulic tester to be sure the 2
flow is correct.
1
There should be approximately 18.0 GPM (68,1 L/min.)
free flow. Turn the restrictor control on the tester, until the Left
main relief valve opens. The correct pressure for the main Steering
relief is 3000 PSI (20685 kPa). Lever
Control
Release the button (Item 2) [C] and push the button (Item Right
1) [C] to disengage the detent position to the front Steering
auxiliary quick couplers. Lever
Control
P–00391 P–00389
If the relief pressure is not correct, stop the engine.
Replace or adjust the main relief valve. (See Page 2–27.)
853, 853H Loader
–2–25– Service Manual
--- Page 12 ---
HYDRAULIC FILTER HOUSING
Removal And Installation
A
Never work on a machine with the lift arms up
unless the lift arms are secured by an approved
lift arm support device. Failure to use an
approved lift arm support device can allow the
lift arms or attachment to fall and cause injury
or death. W–2059–0598 CD–10945
B
1
Disconnect the tubelines from the inlet of the hydraulic
filter [A].
Disconnect the hose (Item 1) [B] from the outlet of the
filter. CD–10946
Remove the two mounting bolts and remove the hydraulic
filter and housing [C]. C
Installation: Tighten the mounting bolts to 25 ft.–lbs. (34
Nm) torque.
CD–10947
853, 853H BICS Loader
–2–35– Service Manual
--- Page 13 ---
HYDROSTATIC SYSTEM
Page
Number
COLD OIL BY–PASS VALVE