Table 2-1. Troubleshooting - continued

Table 2-1. Troubleshooting (Continued)

Malfunction

Probable cause

Corrective action

d. Low oil level.

a. Fill reservoir to correct level (LO

43. Low, oil pressure.

10-3930-618-12).

b. 'Worn hydraulic pump.

b. Recondition or replace (para 4-2).

c. Weak relief valve spring.

c. Replace spring (para 4-2).

d. Relief valve stuck open.

d. Remove and free up valve (para

4-2).

e. Flow control valve stuck open.

e. Free up flow control valve (para

4-2).

f. External leakage.

f. Tighten or replace fittings hoses, or

seals (para 4-2).

g. Internal leakage.

g. Replace seals in pump (para 4-2)

or cylinder (para 4-2).

Section III. GENERAL MAINTENANCE

be sure the chamfered side faces the shoulder.

2-6. General

Lubricate the bearing and its mating surface when

This section contains general maintenance information

pressing a bearing into place. Press bearings only on

that would otherwise have to be repeated throughout this

the race adjacent to the mating part. Use drivers which

manual.

contact as much of the race as possible.

2-7. Maintenance Requirements

e. Repair of Damaged Machined and Polished

a. Hardware and Threaded Parts.

Inspect

Surfaces. Remove rough spots, scores, burs, galling,

hardware for damaged threads, rounded corners, and

gouges, and other surface damage from machined and

damaged slots. Threaded holes and parts should accept

polished surfaces. Use a suitable honing stone, crocus

their mating parts without requiring excessive torque.

or emery cloth, file, or any other method that will permit

Threads may be chased with a tap or die. Replace any

the part to function efficiently. The finish of the part must

threaded parts which cannot be repaired.

approximate that of the original finish. Do not alter

b. Gaskets.

Replace all gaskets .which are

critical dimensions beyond acceptable limits. Build up

disturbed during repair operation or which show evidence

shafts, rods, and other worn parts by metallizing,

of leakage. When installing gaskets, insure all gasket

chrome plating, or welding. Grind built up parts to

surfaces are clean and free from nicks and burs. Use

original size.

grease or gasket cement to retain gasket in position

during assembly procedure.

f. Welding Repair. Welding must be performed by

c. Oil Seals and Packings. Thoroughly lubricate

a qualified welder. Welds must provide complete fusion

the sealing lip of spring loaded seals with grease or other

and

penetration

and

comply

with

governing

suitable lubricant when installing. Apply nonhardening

specifications. Inspect all welds using a radiographic or

sealer to the outer circumference of encased seals or to

magnetic particle process. Grind all new welds flat and

the mating bores to prevent possible leakage. Immerse

smooth whenever possible.

preformed packings in the liquid or lubricant with which

they will be in contact.

g. Part Replacement. Replace parts which are

d. Ball and Roller Bearings.

After removing

worn or defective with new parts. Consider such factors

antifriction bearings, cover them immediately to keep out

as age, mileage, operating hours, usage, and part

dirt and abrasives. Flush thoroughly with solvent, tap

availability to determine the necessity of part

them against a wooden block to remove packed

replacement.

lubricant, and air-dry. Coat cleaned bearings with oil

and wrap in clean paper. Replace any bearings that are

scored, pitted, discolored from overheating, or otherwise

damaged. When installing bearings against shoulders,

Section IV. REMOVAL AND INSTALLATION OF MAJOR

COMPONENTS AND AUXILIARIES

assembly (mast, carriage, and cylinders); steering axle;

2-8. General

and hydraulic system. This section covers direct and

The major components of the fork lift truck are; the

general support maintenance instructions for the

power plant (engine, torque converter, and transmission;

removal,

drive axle (differential, brakes and wheels); hydraulic lift

2-5