Ninety-Eight FWD V6-181 3.0L (1985)
Power Steering Fluid: All Technical Service Bulletins
Power Steering - Reduced Assist at Low Temperatures
NUMBER:
91-T-79
CORP.REF.NO: 033206R
DATE:
March 1991
SECTION:
3B
SUBJECT:
REDUCED POWER STEERING ASSIST AT LOW AMBIENT TEMPERATURES NEW POWER STEERING FLUID
MODELS/YEARS:
1980-91 ALL MODELS
CONDITION:
Comments of reduced power steering assist at low ambient temperatures (approximately 10 degrees Fahrenheit and lower) may be noted by some vehicle
operators when turning the steering wheel in BOTH the right and left direction during warm-up after cold start. All vehicles with power steering exhibit
this condition to varying degrees. Reduced power assist during cold weather starting may be more noticeable in power rack and pinion steering systems.
Power rack and pinion steering systems may contain six feet or more of pressure and return hose along with long cooler lines. Such long systems contain
greater volumes of fluid and vehicles so equipped tend to have longer periods of reduced power assist.
Note:
This condition, which is related to power steering fluid viscosity, should not be confused with conditions having similar symptoms such as
that described in Dealer Technical Bulletin 88-T-139 which relates to internal steering gear fluid by-pass.
CAUSE:
In cold weather, power steering fluid thickens in the same manner as any other petroleum-based oil or fluid. During cold starting, the fluid resists
movement through the system and the driver senses reduced power assist (sometimes referred to as "stiff steer"). As the vehicle operates and fluid
circulates through the power steering system, the fluid warms and thins to its normal operating viscosity.
CORRECTION:
A new Low Temperature Climate Service Fluid has been developed. Compared with conventional power steering fluid, this new fluid flows better at low
temperatures and resists the thickening which contributes to reduced power assist during start up. This new fluid may be used in all Oldsmobile vehicles,
but performs particularly well with current designed rack and pinion steering systems and special remanufactured rack and pinion steering assemblies.
PARTS INFORMATION:
Low Temperature Climate Service Fluid is available from GMSPO. Order as:
Container Size
Part Number
16 ounce
12345866
32 ounce
12345867
Parts are currently available from GMSPO.
SERVICE PROCEDURE:
The power steering fluid replacement procedure is a two-stage process: first, flushing the old fluid from the system with new fluid; and second, bleeding
the system to remove any trapped air. The following two sequences outline the steps in each procedure.
Flushing The Power Steering System
1.
Raise the front end of the vehicle off the ground until the wheels are free to turn.
2.
Remove the fluid return line at the pump reservoir inlet connector.
3.
Plug the inlet connector port on the pump reservoir.
4.
Position the fluid return line toward a large container in order to catch the draining fluid.
5.
While a second person fills the reservoir with new Low Temperature Climate Service Fluid, start and run the engine at idle.
6.
Turn the steering wheel from stop to stop.
Notice:
Do not hold the wheel against stops while flushing the system. Holding steering wheel against wheel stops will cause high system
pressure, overheating, and damage to the pump and/or gear.
7.
Continue draining until all of the old fluid is cleared from the power steering system. Addition of approximately 1 quart of new fluid will be
required to flush system.
8.
Unplug pump reservoir inlet and reconnect return line.
9.
Turn engine off, and fill reservoir to the "Full Cold" mark.
10.
Continue with following procedure "Bleeding the Power Steering System".
