HYDRAULIC LIFT SYSTEM MAINTENANCE

TM 10-3930-638-24&P

2-56. HYDRAULIC LIFT SYSTEM MAINTENANCE

a. Operational Test.

This procedure provides an operational test of the control valve, associated cylinder (lift, tilt, rotation, and sideshift) assem-

blies, and hoses, lines and fittings. This procedure may also be used to quickly troubleshoot the mast assembly to determine

what components are defective.

INITIAL SETUP

EQUIPMENT CONDITION

TOOLS

Paragraph

Condition Description

NSN 4910-00-754-0654

No. 1 Common Organiza -

Vehicle parked on level surface, parking

tional Maintenance Tool Kit

brake applied and engine off.

MATERIALS/PARTS

None

IF INDICATION

NORMAL

IF INDICATION

PROCEDURE/ACTION

STEP

IS ABNORMAL

INDICATION

IS NORMAL

Check hydraulic reservoir

oil level; add hydraulic oil

if oil level is not between

FULL and ADD marks on

dipstick with mast lowered

(refer to current lubrication

order)

Start engine and operate

at idle speed

Check hoses, lines and fittings between control

Place lift control lever

Mast moves

Proceed to step 4

valve and lift cylinder assembly for oil leaks.

in RAISE position; release

upward

Tighten loose fittings/replace leaking hose

smoothly

lever when mast reaches

(para 2-56f). Check lift chains and pulleys

full height

for wear or damage; replace as necessary

(para 2-56d). If hoses, lines, fittings, lift

chains and pulleys okay, notify direct sup-

port maintenance

Proceed to step 5

Proceed to step 7

Place tilt control lever in

Mast moves

forward

FWD position; release

smoothly

when mast is in full

forward position

Reconnect fitting Notify direct support maintenance (tilt

No oil leakage

With mast in full forward

cylinder assembly requires replacement)

to tilt cylinder

at tilt cylinder

position, disconnect fitting

assemblies. Pro-

at rod end of tilt cylinder

assemblies

teed to step 6

port where

assemblies and plug fitting.

fitting discon-

Place tilt control lever in

netted

FWD position and hold

Notify direct sup- Tighten fittings; replace leaking hoses (para

No oil leaks

6 Check hoses, lines and

port maintenance 2-56f(1))

fittings between control

valve and tilt cylinder

(control valve

requires replace-

assemblies for oil leaks

ment)

Change 2 2-393