FLUID LEAKING FROM TRANS VENT (DIAGNOSTIC TIPS/SERVICE INFO)

SUBJECT: FLUID OUT VENT - DIAGNOSTIC TIPS (SERVICE INFORMATION)

MODELS: 1982 - 1990 C/K AND R/V/G/P WITH HYDRA-MATIC 3L80 TRANSMISSIONS

Some diagnostic information to consider if fluid is leaking out the vent:

o Inverted pump gasket or pump gasket off location - Use alignment pins.

o Flatness specification of pump body and cover - Free from burrs.

o Pump passages clear from chips - Visual inspection.

o Overfilled transmission - fluid - Check fluid level at transmission operation temperature.

o Pressure regulator pin hole too shallow causing pump face interference.

Refer to section 7 of the appropriate service manual for repair procedures.

Refer to Truck Service Bulletin 90-7A-118 (Corp No. 067107) for a new fluid level indicator and model application.

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.