TRANSMISSION APPLICATIONS: SUBJECT: 1982-1990 HYDRA-MATIC 3L80/3L80-HD Fluid Out Vent - Diagnostic Tips (M-40) (Service Information)
TRANSMISSION MODELS: VEHICLE APPLICATIONS: All Models C/K, RN, and P-Trucks G-VAN
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.
Refer to the appropriate Service Manual Section for proper repair procedures.
Refer to Dealer Service Bulletin No. 90-406-7A for a new fluid level indicator and model application.
Labor Operation K6130 Time alloted - 0.2 hours
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.