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  1. #1

    Default Leaking Trans Fluid

    Hello folks,I have a 1994 Chevy Z-71 4x4 auto with a 350 throttle body,The truck has 54,000 original miles. recently on a three hour trip it leaked a quart of trans fluid which covered the underside of the truck,it does not leak when sitting only when driving.

    Any ideas? Thanks

  2. #2


    Check the cooler lines running up to the radiator, the overflow vent, then the dipstick, then the gasket around the pan.
    I'd buy some cleaner and hose everything down first to get it as clean as you can, after hosing it down put the rear wheels in the air on jackstands and block the front wheels, then fire it up and put it in gear let is run and see if you can find the leak.

  3. #3


    Thanks for the info tbplus10.Maybe that's all that wrong.

  4. #4


    My first guess would be a leaking cooler line, if it's coming out the dipstick or vent then you've got a heat or pressure problem, could come out the dipstick if the vent is clogged, and the last item would be a bad pan gasket which given the age of the truck (even though it is low miles) wouldnt be out of order. Sitting around and not driving is bad on the seals and gaskets.

  5. #5


    Thanks again for your response,I plan on crawling underneath in the morning and see what I can find. I will update what and if I find the problem.

  6. #6


    Were you towing or hauling a heavy load when it happened? Sometimes these transmissions leak fluid out the breather on the top of the transmission case when towing and the fluid gets hot. Also, how hard were you running the truck? (lots of hard acceleration and such)

    1991 Chevy Suburban 1/2 ton 2WD w/ chevy SBC 350-3/4 ton drivetrain upgrade w/4.10 gears 200K miles
    2005 Saturn ION-2 Stock 265K miles
    1982 Bronco, 1993 Bronco (sold), 1971 M35A2 Deuce and a Half

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