TRUCK SERVICE MANUAL
1. Fill reservoir to indicated level and replace cap.
1. When a driver brings in his truck with a
2. Start engine and idle, turning wheels to the full
complaint, ask him to explain the trouble in his
left and right three times. Shut off engine and
own words. (Sometimes a driver expects easier
refill reservoir to indicated level.
steering than his system is designed to give. ) As
3. Continue operation in step "2" until system
you talk with him, make notes of his comments,
maintains its proper indicated oil level.
look the system over for obvious defects. You
4. Run engine at faster speed and continue turning
may spot at first glance such things as uneven
wheels slowly from full left to full right and back
tire wear, evidence of leakage or a frame out of
again for approximately five minutes to check for
line. Determine the type and arrangement of the
leaks. This will bleed the system of air. Again
power steering system.
refill the reservoir to the indicated level or to 1-
Here are some sample questions you should ask
1/2" below top of filler neck on reservoir without
dipstick attached to filler cap.
a. How does the steering act?
b. Does it act this way all the time?
c. Does it occur in only one direction?
d. Under what conditions does it usually occur?
e. Is it accompanied by unusual noises?
2. If after talking with the driver you are still unable
A. A thorough and orderly troubleshooting
to define the complaint, ask him to accompany
procedure will help you diagnose power steering
you and drive the vehicle yourself. Observe
troubles quickly. Troubles occur in many places,
steering action, think, visualize the system in
show uF in various ways; but with this procedure,
operation. Perform actions in which the driver
you can eliminate many possibilities immediately,
said trouble occurred; try other steering actions
narrow down the cause of trouble, then make
too, to give you a complete and accurate
correct repairs promptly.
definition of the trouble. You may want to try
these steering actions:
1. We have arranged the troubleshooting
procedure into three-steps:
a. Turn steering wheel while standing or moving
a. Define the complaint.
slowly. (Standing with vehicle loaded,
b. External inspection.
hydraulic power may not be sufficient. )
c. Hydraulic system check.
b. Steer in both directions while moving.
2. This procedure is an overall one. By following it
c. Turn steering wheel rapidly one or two turns in
step by step, you should be able to identify nearly
every trouble which may occur in a hydraulic
d. Observe action when traveling straight ahead.
power steering system. As you become more
The second step is an external inspection. Look
familiar with troubleshooting, you can leave out
for the obvious defects first to save time.
some steps on some jobs.
1. Check hydraulic fluid reservoir for correct level.
Insufficient oil will cause loss of pressure and
The first step in finding trouble is to define the
hard steering. An extremely low supply may allow
complaint. Properly identifying the complaint will
air to enter the system causing a "growling" noise
let you eliminate many possible causes at once.
and a "lump" in steering, A reservoir overflow
Just like a doctor, you must know what and
means it is too full, the filter is out of place or in
where the trouble is before you can correct it.
2. Check tire pressure and tire wear due to
improper alignment or balance. Faulty tires can
cause hard steering and other undesired steering