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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: jdnunn1994 on November 08, 2012, 09:21:44 am

Title: Transmission leak
Post by: jdnunn1994 on November 08, 2012, 09:21:44 am
i have had a problem with my transmission in my 1980 big 10 pickup. i had a 305 with a lockout 350 transmission which i hated. i blew the 305 up and put a 350 with a turbo 350 tranny. it seems to leak some and i cant really place where its leaking at. i will have it at operating temperature and check the fluid level, it doesnt even register much on the dipstick, so i put some in it, and it pours out of what looks like a breather of some sort on the drivers side.
Title: Re: Transmission leak
Post by: bd on November 08, 2012, 11:04:40 am
Does the "breather" look like a ~3" diameter steel cover at the left rear side of the transmission (see image)?
Title: Re: Transmission leak
Post by: jdnunn1994 on November 08, 2012, 12:04:44 pm
no its up closer to the front on the drivers side, it looks like a small pipe pointing downward
Title: Re: Transmission leak
Post by: bd on November 08, 2012, 01:06:14 pm
The tube is the case vent.  Fluid leakage from the vent tube may be caused by an internal pressure leak from the pump (gasket, cross-channel leak, pump distortion, debris caught in the lap-fit joints, etc).  Take it to a trusted transmission shop for evaluation.  At some point the trans will probably need to come out.