GM Service Manual Online
For 1990-2009 cars only

HEATER WARMS UP SLOWLY (INST. PLUG IN RADIATOR VENT HOSE)

SUBJECT: HEATER WARMS UP SLOWLY (INSTALL PLUG IN RADIATOR VENT HOSE)

MODELS: 1994 BUICK ROADMASTER 1994 CADILLAC FLEETWOOD 1994 CHEVROLET CAPRICE

CONDITION:

SOME OWNERS MAY COMMENT THAT THEIR VEHICLE WARMS UP SLOWLY.

CAUSE:

COLD COOLANT IS ENTERING THE HEATING CIRCUIT AT THE RECOVERY BOTTLE THROUGH THE COOLANT RECOVERY RADIATOR (RESERVOIR TO RADIATOR) HOSE (ALSO REFERRED TO AS THE RADIATOR VENT HOSE).

CORRECTION:

PERFORM THE FOLLOWING MODIFICATION TO RESTRICT FLOW TO THE COOLANT RECOVERY BOTTLE FROM THE RADIATOR.

CAUTION:

THE FOLLOWING PROCEDURE INVOLVES MODIFICATION OF A COOLANT HOSE. ANY COMPONENT OF THE COOLANT SYSTEM ON THESE VEHICLES MAY CONTAIN HOT COOLANT UNDER PRESSURE. ALLOW THE VEHICLE TO COOL THOROUGHLY BEFORE PERFORMING THIS MODIFICATION.

1. AFTER ALLOWING VEHICLE TO COOL THOROUGHLY, SLOWLY REMOVE CAP FROM PRESSURIZED COOLANT BOTTLE.

2. LOCATE THE COOLANT RECOVERY RADIATOR (RESERVOIR TO RADIATOR) HOSE (SEE ILLUSTRATION). OUTSIDE DIAMETER OF HOSE IS APPROXIMATELY 5/8" (16 MM).

3. REMOVE HOSE FROM THE PRESSURIZED BOTTLE ONLY.

4. INSERT A 3/8" (9.5 MM) DIAMETER X 1" (25.4 MM) LONG PLUG INTO THE VENT HOSE (A STUD WORKS WELL IN THIS APPLICATION). USING THE APPROPRIATE TOOL, PUSH THE PLUG AT LEAST 1-1/4" (31.8 MM) INTO THE HOSE.

5. INSTALL AN APPROPRIATE SIZE HOSE CLAMP ON THE HOSE CENTERED ON THE PLUG. THIS CLAMP WILL PREVENT THE PLUG FROM MOVING AS WELL AS SEAL THE HOSE TO THE PLUG IN ORDER TO PREVENT COOLANT FLOW THROUGH THE HOSE.

6. INSTALL THE COOLANT RECOVERY RADIATOR HOSE BACK ON THE PRESSURIZED COOLANT BOTTLE.

7. CHECK COOLANT LEVEL AND ADD AS NECESSARY.

8. INSTALL CAP ON PRESSURIZED COOLANT BOTTLE.

WARRANTY INFORMATION:

FOR VEHICLES REPAIRED UNDER WARRANTY, USE: LABOR OPERATION: J3252 LABOR TIME: 0.2 HR.

FIGURES: 1


Object Number: 86364  Size: LF

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.

COPYRIGHT 1994 GENERAL MOTORS CORPORATION. ALL RIGHTS RESERVED.