Section VIII. HYDRAULIC PUMP

TM 10-3930-621-34

10-36. Installation

a. Refer to figure 10-10 and install as follows:

b. Using care not to damage tubing, lift reservoir (1)

into position at bottom of truck and secure it with long

screws (6), short screws (7), lock washers (9), flat

washers (8), bushings (10), and nuts (11). Use long

screws (6) on frame crossmember side of reservoir.

Note. Mounting clips are on lower portion of tank on

crossmember side.

c. Secure drain cover (13) and new packing (15) to

bottom of reservoir (1) and install drain plug (12) in

cover.

d. Secure elbow (5) in coupling at side of reservoir

and attach power steering hydraulic line to elbow.

e. Check that reservoir is securely mounted and

then lower truck to floor.

f. Connect suction and return hydraulic lines to

connections at top of reservoir (1).

Note. Suction line is the larger of the two lines and

fits the bent tubing on the crossmember end of the

ME 3930-621-35/10-10

reservoir.

g. Install breather (2) and screen (4) in reservoir.

Reservoir

Lock washer

h. Refer to TM 10-3930-621-12 and fill reservoir

Breather

10.

Bushing

with specified hydraulic oil.

Gage

11.

Nut

Caution: NEVER USE BRAKE FLUID. When

Screen

12.

Plug

filling tank, make sure containers and surrounding

Elbow

13.

Cover

parts are clean, to prevent oil contamination. Any

Screw, long

14.

Nut

hydraulic oil used must contain a rust preventative

Screw, short

15.

Packing

and an oxidation inhibitor. The oil should not foam.

Flat washer

i. Install gage (3) in tank.

j. Install floor plates (TM 10-3930-621-12).

Figure 10-10. Hydraulic reservoir, exploded view.

Section VIII. HYDRAULIC PUMP

power steering gear when the steering gear is operated.

10-37. Description

If pressure above 2000 psi develops when control levers

The hydraulic pump is a gear type unit, driven directly

are operated, it is by-passed at the control valve.

through a coupling from the engine crankshaft.

Reservoir oil is drawn through a suction port and directed

10-38. Removal

by a spool to the power steering port at a maximum

a. Refer to figure 10-11 and remove as follows:

pressure of 1200 to 1300 psi with engine speed at 1400

b. Remove radiator grille guard (TM 10-3930621-

rpm. When a specified flow is reached, the relief valve

12).

spring in the control valve compresses, allowing the

c. Disconnect hydraulic lines to power steering

spool to reposition and direct flow to the control valve

gear, control valve, and suction ports (TM 103930-621-

port. A check valve on the power steering port of the

12).

pump maintains a steady 1000 to 1300 psi to the

10-20