Section Il. MAIN HYDRAULIC PUMP AND ENGINE DRIVEN PUMP

TM 10-3930-634-34

d. Reassembly and Installation. Refer to figure lines.

6-22 and reassemble and install hydraulic suction

6 - 1 4 . Main Hydraulic Pump

(3) Inspect the shafts for scratches, nicks, and

worn areas.

a. General. The main hydraulic pump is a dual

(4) Inspect the gears for scored areas and for wear

p u m p . The larger portion of the pump supplies

and other damage.

hydraulic pressure to the lift cylinders and to the ex-

(5) Inspect all other parts for wear and damage.

tension cylinder. The smaller front section of the

(6) Replace all seals, packing, and defective parts

pump supplies pressure for front wheel steering,

during reassembly.

b. Removal. Remove the main hydraulic pump (TM

e. Reassembly. Refer to figure 6-23 and reassemble

10-3930-634-12).

the main hydraulic pump.

c. Disassembly. Refer to figure 6-23 and disas-

NOTE

semble the main hydraulic pump.

After reassembly, run the pump for 30 min-

d. Cleaning and Inspection.

utes at 2000 rpm while pumping SAE No. 10

(1) Clean all parts thoroughly, using solvent

oil at 0 psi pressure.

P-D-680 or equal.

f. Test. Bench test the pump by driving it at 2400

(2) Inspect the bearings for roughness and loose-

rpm. With the pump loaded to 1950 psi, the flow from

ness or wear.

the front portion of the pump should be 19.2 gallons

per minute. With the pump loaded to 2250 psi, the

priority rear flow should be 8.0 gallons per minute.

g. Installation. Install the main hydraulic pump

(TM 10-3930-634-12).

6-15. Engine Driven Hydraulic Pump

a. General. The engine driven pump is coupled di-

rectly to the engine balance shaft drive gear, where it

is driven at engine speed. It supplies hydraulic pres-

sure to the brakes, side shift cylinder and oscillator

cylinder.

b. Removal. Remove the engine driven hydraulic

pump (TM 10-3930-634-12).

c. Disassembly. Refer to figure 6-24 and disas-

semble the engine driven hydraulic pump.

d. Cleaning and Inspection.

(1) Clean all parts thoroughly, using solvent

P-D-680 or equal.

(2) Inspect the bearings for roughness and loose-

ness or wear.

(3) Inspect the shafts for scratches, nicks, and

worn areas.

(4) Inspect the gears for scored areas, wear and

other damage.

(5) Inspect all other parts for wear, cracks and

other damage.

(6) Replace all seals, packing, gaskets and defec-

tive parts during reassembly.

e. Reassembly. Refer to figure 6-24 and reassemble

the engine driven hydraulic pump.

NOTE

After reassembly, run the pump for 30 min-

utes at 2000 rpm while pumping SAE No. 10

oil at 0 psi pressure.

6-13