Cooling System - Leak Diagnostic Procedure
88pontiac20Bulletin Number: 89-6-10
Reference Number: 836209R
Publish Date: 10/88
Subject: ENGINE COOLING SYSTEM LEAKS (DIAGNOSTIC PROCEDURE)
Models
Affected: ALL 1980-89
"This bulletin cancels and replaces bulletin 88-6-48, dated 5/88. This bulletin has been revised to include additional detailed information."
Engine cooling system leaks which may occur may be due to several possible reasons. Refer to the Service Manual to properly diagnose the reason for a leak. Assure the cooling system is full of coolant before performing the diagnosis.
Also, the following systems should be inspected for proper function.
1. All hose joints for possibility of loose or misaligned clamps.
2. All gasketed joints for possibility of loose fasteners, damaged gaskets, or damaged surfaces.
3. Coolant recovery system for possibility of vacuum leaks or a damaged seal surface at the coolant filler cap assembly.
4. Water pump assembly for possibility of a slight leak from the weep hole.
NOTICE: A VERY SLIGHT AMOUNT OF WEEPAGE OCCURS AT THE WATER PUMP WEEP HOLE DURING NORMAL OPERATION. TRACKS OF RESIDUE FROM THE LOWER WEEP HOLE ARE NOT UNUSUAL. THE WATER PUMP SHOULD BE REPLACED ONLY IF COOLANT IS DRIPPING FROM THE WEEP HOLE WHILE THE ENGINE IS IN OPERATION OR WHILE THE COOLING SYSTEM IS PRESSURIZED.
Minor engine coolant system leaks not corrected through normal service procedures, may be corrected by adding (2) sealant pellets, Part Number 3634621, to the coolant system. The pellets are available from GMSPO.
The pellets should be added to the coolant system under the following conditions:
1. Vehicles with minor coolant leaks/loss that cannot be corrected through normal service procedures. and/or
2. Engine repair work that requires coolant drainage and replacement with new coolant.
The two sealant pellets should be installed into the radiator filler neck. The pellets may have to be crushed prior to installation.
NOTICE: DO NOT ADD THE SEALANT INTO THE COOLANT RECOVERY BOTTLE. THE USE OF THE SEALANT PELLETS MAY CAUSE A FILM TO APPEAR AROUND THE SIDES OF THE COOLANT RECOVERY BOTTLE. THE PRESENCE OF THIS FILM IS CONSIDERED TO BE NORMAL.
Following installation of the pellets, run the engine for approximately 15 minutes, then check for coolant leakage.
Use applicable labor operation and time.