Cooling - Bypass Kit Improves Performance
Bulletin 85-6B-3Date Apr. '85
Ref. No.. 85-117-6B
SUBJECT: BYPASS ENGINE COOLANT KIT
MODELS AFFECTED: 1985 ELECTRA WITH 3.8L MFI ENGINE (LN3) 1984-1985 CENTURY WITH 3.8L MFI ENGINE (LN3)
CONVERSION KIT - WATER BYPASS, PART #25526634:
A new service kit to revise 3.8L MFI engines built prior to December, 1984 is now available. This additional bypass supplements that already provided through the heater. This kit must be used in conjunction with the new style water pump and gasket in kit part number 25525147 and three (3) tablets (tabs) of 3634621* (6 tabs per package) cooling system supplement or a locally available equivalent such as "Bars Leak". The bypass kit part number 25526634 contains an adapter, connector, pipe assembly, hose, clamps (2), instruction sheet, 195~ thermostat, and thermostat gasket.
Several performance changes are provided by installing this kit including:
reduced engine coolant temperature cycling; reduced temperature gauge cycling or an intermittent hot light; reduced possibility of trapped air in the engine; and if the 195~ thermostat assembly included in the kit is installed, increased heater air output temperature about 10~F. The thermostat must be changed if not previously changed. Three tabs of cooling system supplement or equivalent must be added before reinstalling radiator cap to assure protection is maintained at original factory levels.
A bypass kit is being developed for the Somerset 3.0L MFI engine (LN7).
Warranty Information
Century Century Electra Electra
Including Without Including Without
195~F Therm. Therm. Change 195~ Therm. Therm. Change
Labor Hours: 2.6 2.2 2.0 1.6
Labor Operation #: T5092
Trouble Code: 92
* Order as direct ship maintenance material from GMWDD.