CHAPTER 5 REPAIR OF STEERING- SYSTEM

TM 10-3930-631-34

CHAPTER 5

REPAIR OF STEERING- SYSTEM

Section I. DESCRIPTION AND PRESSURE CHECK

5-1. Description

a. The steering system of the lift truck is

hydraulically powered. A separate hydraulic pump

supplies pressure to actuate the system (fig. 3-1).

b. Main components of the system are the steering

hydraulic pump, the steering valve unit and the steering

cylinder. Oil for the system is supplied from the main

hydraulic reservoir. Rotation of the steering wheel opens

ports in the steering valve unit and transmits pressure to

the cylinder. The piston in the cylinder moves under the

pressure, extending or retracting the cylinder rod. The

cylinder rod is connected to a drag link which in turn

actuates the steering axle pivot arm. Movement of the

pivot arm pulls or pushes the tie rods which are attached

to the spindles. As the wheels are mounted on the

spindles the wheels turn guiding the truck in the direction

desired.

5-2.Steering Pressure Check and Adjustment

a. Pressure Check. Check and adjust system

pressure as follows:

(1) Drive truck up on ramp or raise truck on a

Figure 5-1. Pressure gage location.

suitable lift to gain access to pump.

(2) Remove floor and toe plates to gain access

(5) Connect the battery, depress the seat to

to the steering valve unit.

close the switch and turn the master switch on. Pump

(3) Disconnect the pressure hose from the

motor will run continuously while master switch is on and

pump to the adapter in the steering valve unit at the

seat is occupied.

adapter.

(6) Turn wheel right or left and place a block

(4) Install a suitable tee fitting as shown in figure

between spindle and steer axle. Turn steering wheel to

5-1 at the adapter. Install a pressure gage (0-3000 psi)

force steering wheel against block. Observe needle on

(0-210.9 kg/cm2 ) in the tee.

pressure gage. If pressure of

5-1