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

TRANSMISSION APPLICATIONS: 1982-1990 HYDRA-MATIC 3L80 3L80-HD (M-40)

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

TRANSMISSION MODELS: ALL MODELS

VEHICLE APPLICATIONS: C/K, R/V AND P TRUCKS, G-VAN

Service Information:

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.

- Pressure Regulator Pin hole too shallow causing pump face interference.

Service Manual Reference:

Refer to the appropriate Service Manual Section for proper repair procedures.

Refer to Product Service Bulletin 90-73L80-106 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.