Section VIII. REPAIR OF HYDRAULIC DIRECTION CONTROL VALVE

TM 10-3930-609-35

3-46. Disassembly of Hydraulic Pump (fig. 3-10).

3-49. Repair and Replacement of Hydraulic Pump

Parts

a. Remove retaining ring from internal groove in

mounting flange cover; then, take out capscrews which

a. Repair minor thread damage with tap or thread

secure mounting flange cover to pump housing.

chaser.

b. Carefully separate mounting flange cover from

b. Replace parts that are cracked or distorted or

pump housing and take out seals, packings, drive gear

that are excessively worn.

shaft, driven gear shaft, bearings and packing retainer.

c. Replace all packings and' seals at each

c. Do not remove pins from pump housing unless

reassembly.

replacement is required.

3-50. Reassembly of Hydraulic Pump (fig. 3-10)

3-47.

Cleaning Disassembled Parts of Hydraulic

a. Press pins into holes in pump housing until pins

Pump

bottom.

a. Wash all parts in SD and dry with soft cloth or

b. Install large packing in recess in mounting

with compressed air under moderate pressure.

flange cover.

b. Ensure that all fluid passages in housing are

c. Install packings on flanges of bearings and

free of obstructions.

secure with packing retainers.

d. Install small packings in recesses of pump

3-48. Inspection of Hydraulic Pump Parts

housing.

a. Inspect all threaded parts and tapped holes for

e. Assemble bearings on both ends of drive gear

stripped threads or other damage.

shaft and driven gear shaft; then, insert shafts into pump

b. Inspect mounting flange cover, housing, drive

housing.

gear shaft and driven gear shaft for cracks and

f. Carefully aline mounting flange cover with pump

distortion.

housing and shafts; then, secure to pump housing with

c. Inspect bores in bearings for scoring and pitting

capscrews.

and for excessive wear as indicated by loose fit on

g. Insert seal into mounting flange cover around

bearing surfaces of drive gear shaft and driven gear

end of drive gear shaft and secure with retaining ring.

shaft.

d. Inspect teeth on drive gear shaft and driven

3-51. Installation of Hydraulic Pump

gear shaft for pitting, chipping and excessive wear.

After hydraulic pump has been reassembled, reinstall

e. Inspect interior surfaces of pump housing for

pump on truck. Refer to paragraph 2-21 for installation

scoring, pitting and other damage.

procedure.

Section VIII. REPAIR OF HYDRAULIC DIRECTION CONTROL VALVE

3-54. Disassembly of Control Valve (fig. 3-11)

3-52. Description of Control Valve

The hydraulic direction control valve is a two-spool fluid

a. Remove relief valve cap nut, loosen jamnut in

control valve with a spring loaded control handle for

adjustment setscrew; then, unscrew adjustment

each spool. The inboard control handle and spool

setscrew from relief valve plug.

control fluid flow to and from hoist cylinder for raising

b. Unscrew relief valve plug from valve body and

and lowering the forks. The outboard handle and spool

take out spring seat, spring and poppet. Remove

control fluid flow to the two tilt cylinders. Each control

packing from groove in poppet.

handle has two actuating positions and a center neutral

c. Remove plug from valve body opposite relief

position.

valve and take bearing out of valve body.

d. Remove plugs from valve body opposite

3-53. Removal of Control Valve

plungers; then, remove gaskets from plugs.

Removal of control valve from truck is required for

overhaul as described in the following instructions.

Refer to paragraph 2-17 for removal procedure.

3-18