only have reverse on our 1993 chevy sierra1500 we hear allot of stories about that transmisson that r in them what model comes in the 1500 whatis the problem with them
sounds like that Chevy in "smoke signals"~ but sounds to me like a vacuum problem...the vacuum modulator or manifold is leaking...stick an eye under there with the parking brake set, and see if you can find a displaced vacuum hose...if you cannot find a hissing manifold...might have to take it to a transmission shop~
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