Cleaning, Inspection, and Replacement

TM 10-3930-621-34

(5) Insert disk (12), long spring (13), new

10-40. Cleaning, Inspection, and Replacement

packing (16), and disk (15) on power steering port side of

Refer to figure 10-11 and clean, inspect, and replace as

spool.

follows:

(6) Insert new packing (19), short spring (20),

a. General.

and new packing (21) on control valve port side of spool.

(1) Clean all parts with cleaning compound,

(7) Install plugs (14 and 22) on both ends of

solvent (Spec.

P-S-661).

Dry thoroughly with

spool chamber, being careful not to disturb pop jet

compressed air.

seating in spool.

(2) Remove nicks and burrs from all parts with

(8) Install suction line elbow (39).

emery cloth.

c. Install new packing (23) in back plate recess and

b. Drive and Idler Gears.

diaphragm seal (29) into recess of front plate (7). Install

(1) Inspect drive gear shaft (25) for worn splines.

new gaskets (27 and 28) into lip of diaphragm seal.

(2) Inspect both drive gear (25) and idler gear

d. Install and hold ball (34) and springs (35) in

(36) at bearing and seal contact points for rough

position in front plate (30).

surfaces and excessive wear.

e. Install new diaphragm (26) into lip of diaphragm

(3) Inspect both drive and idler gear faces for

seal (29) on top of gaskets, ball and spring. Check to be

scoring and excessive wear. If edges of teeth are sharp,

sure diaphragm fits securely into diaphragm seal lip.

break edges with emery cloth.

f. Dip gear assemblies (25 and 36) in hydraulic oil

c. Bearings.

and slip them into front plate (30) bearings.

Note. Bearings are part of plate assemblies (30

Turn gears and check for free rotation.

and 44) and are not available separately.

g. Aline body assembly (24) dowels with front plate

(1) Inspect all bearing oil grooves. Grooves

dowel holes and tap body with nonmetal object until body

should be half way between horizontal and vertical on

is firmly seated against front plate (30).

pressure side of pump.

h. Aline back plate (44) dowel holes with body

(2) Check to see if front plate assembly (30)

assembly (24) dowels and install back plate on body.

bearings are flush with islands in groove pattern.

i. Place pump in vise, shaft up, and secure plate

d. Back Plate Assembly. Check for scoring on face

assemblies (30 and 44) and body assembly (24) with flat

of back plate assembly (31). If wear exceeds 0.0015 of

washers (31) and bolts (32). Torque bolts to 25 foot-

an inch, plate should be replaced.

pounds.

e. Body Assembly. Check inside of gear pockets in

j. Oil drive shaft seal (33) and install carefully over

pump body for excessive scoring or wear.

drive shaft (25) splines.

f. Spool and Poppet Seat. Carefully examine flow

k. Rotate pump shaft by hand. Pump should have

divider spool (17), sleeve (18) and poppet seat (11) for

some drag, but should turn freely after a short period of

wear or damage.

use.

10-41. Assembly

10-42. Installation

a. Refer to figure 10-11 and assemble the pump

a. Be sure hydraulic system contains clean oil

unit as follows: b. Use the following procedure to

before installing pump.

assemble back plate assembly.

b. Refer to figure 10-11 and install pump as follows:

(1) Install elbow (40) in control valve port and

a. Install coupling (3) to crankshaft pulley with lock

new packing (43), adapter (42), and check valve (41) in

washers (2) and bolts (1).

power steering port.

d. Attach pump plate to pump assembly with lock

Note. All ports are marked for correct

washers (37) and screws (38).

installation.

e. Insert pump shaft into coupling (3). Shaft should

(2) Carefully insert spool (17) and sleeve (18)

slide easily into coupling. If it binds, remove pump and

into back plate and center.

inspect coupling and shaft for burrs or other damage.

(3)

Install poppet seat (11) and poppet

assembly (10) in back plate so that seat is firmly seated

in proper groove in the spool (17).

(4) Holding the back plate (44) in the upright

position to insure proper seating of poppet, install spring

(9), new packing (8), shim (7), and plug (6).

Adjust spool (17) accordingly, before tightening plug.

10-23