I have a 1998 Chevy Blazer 4x4 4.3 engine. I am having a problem with the transmission leaking fluid out of the breather tube attached to the Dip stick tube. I trace the line to a 3 way vacuum valve on the top drivers side of the tranfer case. It has 3 vacuum lines going to it and is pulling fluid from it through the lines , they are vacuum lines and I assume they shouldn't have fluid in them at all. I replaced the valve because I figured it was bad and letting fluid come through, That didn't help. The valve I think is for the shifting of the 4high and low, just wondering if maybe the new valve was bad which I doubt but could be I guess,or it isn't supposed to have fluid where the valve is and has some internal problem with the transmission/Tranfer case. Thanks, BY the way love this car, had it since 2000.

 

Welcome to the forums, the most probable cause is a failed input seal on transfer case. Very common issue that lets transmission fluid enter transfer case and getting trapped to the point it is overfilled and will push fluid out breather and into places it shouldn’t be. Pretty straight forward repair but beware it can get really messy really quick. Best way to confirm the issue is to remove the fill plug on Tcase and see if fluid pours out. Just be ready with a pan and rags. Have you been adding fluid to transmission on a regular basis?
Brad

 

Thanks, don't drive it much so haven't added much fluid, is the filler plug on the driver side of the tranfer case?

 

Yes the fill and drain are on the drivers side rear of Tcase.
Brad

 

Thanks Brad, it was the seal, got it repaired yesterday, wasn't to bad a job, I have done a lot worse. Also the check engine light had been on but went out when I road tested it, only thoughts I have on that is it was sucking trans fluid into the engine and setting off the light,I had noticed a fluid smell when I was driving it before and now I don't , not sure that's the case but it's out all the same. Thanks again.
Mark

 

Thanks for posting the results! Always nice when someone else can follow a post to completion. Glad it worked out.
Brad

 

Thanks for the info, I may have figured it out sooner or later but the info really helped me move along much faster.
Mark