Power Steering - Fluid Filling/Bleeding Precautions

Date: November 26, 2008

Order No.: S-B-46.30/40b

Supersedes: P-B-46.30/40a dated Nov. 27, 2007

Group: 46





Revision History

SUBJECT:
All Passenger and Light Truck Models

Flow Noises from Area of Power Steering Pump and/or Foaming of Power Steering Oil in Reservoir

If you receive customer reports in the above model vehicles of flow noises from the area of the power steering pump, and/or foaming of the power steering fluid in the reservoir following work carried out on the hydraulic steering system; this may be caused by an improper procedure followed for filling fluid and bleeding of the hydraulic power steering system.

To remedy, it is absolutely necessary to make sure that the procedure described in the WIS documents is strictly adhered to. In particular, it is necessary to turn the steering to full lock-to-lock at least 30 times BEFORE STARTING THE ENGINE. If this is not done prior to starting engine, there is a high risk of air entering the steering system, which is subsequently very difficult to eliminate.

NOTE:
Starting the engine prior to bleeding can cause irreparable damage to the power steering pump and will cause an air cushion to form in the steering gear which causes noise. Once the air is ingested, the ingested air will only dissipate after driving the vehicle for more than 30 miles.





Refer to the chart for the correct WIS document reference for the proper filling and bleeding procedure of the power steering pump.