Loader Bobcat 853, 853H. Manual - part 29

COLD OIL BY–PASS VALVE (Cont’d)

Removal And Installation (Cont’d)

Disconnect the oil cooler outlet tubeline (shown) and the
front auxiliary valve charge hose (not shown) from
by–pass valve [A].

NOTE: The auxiliary valve charge hose is next to the

oil cooler outlet tubeline on the by–pass
valve. The (S/N 5101) loader without front
auxiliary hydraulics does not have the
auxiliary valve charge hose.

Remove the by–pass valve mounting bolt and remove the
valve [B].

A

CD–11003

B

CD–11004

–3–22–

853, 853H Loader

Service Manual

HYDROSTATIC PUMP

Removal And Installation

Remove the hydrostatic pump/engine assembly from the
loader. (See Page 7–1.)

Remove the belt shield clips (Item 1) [A] and belt shield
(Item 2) [A].

Loosen the tensioner pulley nut (Item 1) [B].

Remove the drive belt (Item 2) [B].

Installation:  Tighten the drive belt to the correct
specifications. (See Page 3–32 or 3–41.)

Remove the washer and nut (Item 1) [C] from the
hydrostatic pump drive shaft.

Installation:  Tighten the nut to 175–200 ft.–lbs.
(237–271 Nm) torque.

Install the nut on the end of the pump drive shaft (without
washer).

Use a puller (Item 1) [D] to remove the pulley from the
pump drive shaft.

A

P–04924

1

2

1

1

C

P–04931

1

D

P–04932

1

853, 853H Loader

–3–23–

Service Manual

B

P–04926

2

1

HYDROSTATIC PUMP (Cont’d)

Removal And Installation (Cont’d)

Remove the two mounting bolts (Item 1) [A] and nuts
(Item 1) [B].

Installation:  Tighten the mounting bolts and nuts to
65–70 ft.–lbs. (88–95 Nm) torque. Make sure the key
(Item 2) [A] is installed.

Remove the mounting bolt (Item 1) [C] at the hydraulic
pump end of the pump.

Remove the hydrostatic pump from the mounting bracket
and drive belt housing.

SEE THE COMPONENT REPAIR MANUAL FOR
HYDROSTATIC PUMPS FOR DISASSEMBLY AND
ASSEMBLY PROCEDURE.

A

P–04933

2

1

1

C

P–04946

1

–3–24–

853, 853H Loader

Service Manual

B

P–04935

1

HYDROSTATIC PUMP (Cont’d)

Replenishing/High Pressure Relief Valve

There are four replenishing/high pressure relief valves
(Item 1) [A] in the hydrostatic pump. Two are located at
the front of the pump and two at the rear of the pump.

See Page 3–4 for valve function.

Remove the plug spring and high pressure relief valve
from the pump [B].

Check for damage and replace as needed.

Ref.

Description

1.

PLUG

2.

O–RING

3.

SPRING

4.

HIGH PRESSURE RELIEF

A

P–04936

1

853, 853H Loader

–3–25–

Service Manual

B

P–04938

4

3

1

2