Mystery tranny drip.

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nikondude1

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I picked up a clean 99 Yukon 4x4 in February with about 124k on the odo. Runs great, drives great, everything works good. I have reason to believe that at least the motor has been replaced judging by some observations down below and elsewhere, I haven't researched that yet but will.

Anyway, it has not leaked a drop of anything until I saw a couple of drips after it sat for 3 or 4 days on a steep driveway below the rear passenger side tranny pan corner. This has happened two times in about a span of 6 months. Didn't worry about it too much either time.

Until now. Got home this morning and saw it sitting there with a huge amount of transmission fluid running down the driveway from the same place on the pan, about a quart +/-. There wasn't a drop there before I left for work (graveyard shift). Have not driven it for about 6 days this time. I checked the fluid level per the owners manual instructions and found it to be low, I added about a quart to bring it back up where it needs to be.

Any ideas what might be causing this? It won't leak a drop until it has sat for 3+ days w/o driving, and I don't know if the steep driveway has anything to do with it. Also, it only happens during the night. I did a search before this and found nothing.

Thanks guys.
 

95TwinTT

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Might be the pan gasket. When the truck sits for a few days, the fluid slowly drains back to the pan, from the torque converter and other places in the trans. That increased level in the pan after a few days can encourage the leak.

Probably needs a new gasket. That would be a good time to change the filter. :)
 
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nikondude1

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I thought about the torque converter draining back too, kind of explains the steep driveway and fluid building up against the (bad) gasket. Think I'll pick up a new filter and gasket.

Thanks for the reply
 

blueflamed03

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agree with Del, might be a good time for pan gasket and filter/fluid change while your at it.

Welcome to the site!
 
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nikondude1

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Mystery solved...

I went ahead and changed the filter/gasket. Added the new fluid and it was leaking before I backed it out of the garage. I knew it wasn't the gasket at that point, duh. Probed further into the area where it was leaking and found it leaking past the electrical connector. The connector was not seated properly and worked it's way down, about a 1/4", into the tranny. Enough for the fluid to leak past, and after it sat for a while on the inclined driveway the fluid would slowly rise up to the connector and out. I pulled it back up and it seems to be OK for now. If it starts again, I'll just pull it back up, clean around it good, place some sealer around it and let it set up. Not like it would be hard to remove if it had to be serviced.

Hope this helps anyone who might be experiencing the same problem.
 

grnrpr68

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mystery solved...good job the worst thing i think is a vehicle leaking all over the garage floor sucks ass....
 

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