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.