AUTO TRANS COOLER & FLUID LINE INSPECTION & SERVICE PROCEDURE

SUBJECT: AUTO TRANSMISSION COOLER AND FLUID LINE INSPECTION

VEHICLES AFFECTED: 1988-89 W4,W5,W6 AND W7 FORWARD/TILTMASTER W/AUTO TRANSMISSION

SERVICE INFORMATION

In the event of an inoperative automatic transmission, the following steps should be taken to ensure the reliability of the rebuilt or replaced unit.

1. FLUSHING

If metal particles or clutch facing materials are found in the automatic transmission oil pan:

(a) The automatic transmission cooler and automatic transmission lines must be flushed. Fill the cooler and lines with fresh ATF and purge with compressed air (40 psi or less).

(b) Collect the fluid and discharged materials in a suitable container.

2. INSPECTION

Inspect the fluid and materials discharged from the flushing process.

(a) If no metal particles have settled in the container, reuse the cooler and lines. Replace the external automatic transmission oil filter when applicable.

(b) Fine metal particles found in suspension in the automatic transmission fluid is not cause to replace the cooler or lines. Simple flushing of the system will eliminate fine particles from cooler and lines.

(c) If excessive metal flakes or pieces have settled in the container, replace the cooler (on all models) and the external automatic transmission oil filter. Replacement of all bearings within the transmission is recommended.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.