C 3500 Truck 2WD V8-305 5.0L (1988)
Fan Clutch: All Technical Service Bulletins
Engine Overheat - Snowplows Vs Air Flow
TSB # DCS1891
Date:
03-30-88
BULLETIN ID:
869702 REQUESTING DIVISION, GM TRUCK AND BUS ENGINE OVERHEAT
1988 K MODEL SIERRAS EQUIPPED WITH GASOLINE ENGINES AND AFTERMARKET SNOWPLOWS
THIS IS A GMC TRUCK DCS MESSAGE
THIS DCS SHOULD BE GIVEN TO THE DEALERSHIP SERVICE MANAGER
Some comments have been received involving 1988 K model Sierras equipped with aftermarket snow plows about engine overheat while driving on the
highway with the plow in the raised position.
Vehicles which exhibit this condition can be addressed by disengaging the thermal spring on the front of the fan clutch. The procedure for doing this is
to remove the outside end of the thermal spring from its slot and rotate it 90 degrees toward its relaxed position. This will cause the fan to run in the
maximum engaged position all the time.
Note:
This procedure will result in increased fan noise. However this procedure is intended to provide an interim correction for the affected vehicles.
A permanent service correction will be issued on a Truck Service Bulletin in early 1988.
