SERVICE MANUAL UPDATE LOW COOLANT FILL PROCEDURE

LOW COOLANT FILL PROCEDURE (SECTION 6B, PAGE 3)

VEHICLES AFFECTED: 1988 W-CARS WITH 2.8L ENGINE ------------------

SERVICE MANUAL UPDATE

Customers driving the above mentioned vehicles may comment on the following:

1. Engine overheat condition. 2. Low coolant indicator flashing or remaining on. 3. Loss of heater system Performance.

These conditions may be the result of air trapped in the coolant system and/or a low coolant level.

To repair this condition, the following service inspection and coolant fill procedure should be performed:

- Inspect coolant system for proper fill level and operation (see Section 6B).

CAUTION:

TO AVOID THE DANGER OF BEING BURNED, DO NOT REMOVE RADIATOR CAP WHILE ENGINE AND RADIATOR ARE STILL HOT. SCALDING FLUID AND STEAM MAY BE BLOWN OUT UNDER PRESSURE IF THE CAP IS TAKEN OFF TOO SOON.

Fill coolant system to the proper level by:

1. Checking that the radiator drain valve is closed tightly.

2. Open radiator air bleed vent on thermostat housing two or three turns and remove clamp and rubber elbow from bypass pipe. (see Figure 1).

NOTICE: USE ETHYLENE GLYCOL COOLANT, MEETING GM SPECIFICATION 1825-M, TO PROVIDE THE REQUIRED FREEZING AND CORROSION PROTECTION. USE AT LEAST 50 PERCENT SOLUTION, MINUS 37 DEGREES CELSIUS (MINUS 34 DEGREES FAHRENHEIT

3. Fill radiator through neck until full. Close the air bleed vent tightly, connect rubber elbow to bypass Pipe, and tighten clamp.

4. Block drive wheels and Place transaxles in "PARK" (automatic transaxle), or "NEUTRAL" (manual transaxle), and set the parking brake.

5. Start the engine and let idle for five minutes, continue adding coolant as required to keep coolant level to the base of the filler neck. At the end of five minutes, install radiator cap, making certain that the arrows line up with over-flow tube.

6. Add sufficient coolant to the recovery reservoir to raise coolant level to the "HOT" mark.

NOTICE: THE LOW COOLANT INDICATOR LAMP MAY COME ON AFTER THIS PROCEDURE. OPERATE THE VEHICLE SO THAT THE ENGINE HEATS UP AND COOLS DOWN TWO TIMES. IF THE LOW COOLANT INDICATOR LAMP DOES NOT GO OUT, OR FAILS TO COME ON AT IGNITION CHECK, AND COOLANT IS AT THE LEVEL INDICATED IN STEP 6, REFER TO ELECTRICAL DIAGNOSIS (SECTION 8A).

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.