Leaking transmission cooler - BMW Forum

Laker · 10-18-2005, 08:40 PM

I removed trans cooler and replaced the two o-rings and that did not stop the leak. I was unable to pinpoint the leak, so I tried the o-rings first. I Pressure tested the cooler to about 20 psi and no leaks. What I'm wondering is what psi the transmission fluid is, in the trans cooler? Maybe I need greater pressure for testing for leaks? Car is 1994 325IC

Furious · 10-19-2005, 06:39 AM

thats a very good question, to be honest i have no idea what psi the tranny runs at, but are you sure when you did your rings that there was no cracks on the bottom side of the pan?

Laker · 10-19-2005, 09:28 AM

I was able to take a close a the trans cooler and the o-rings are not leaking but I still have a leak somewhere. I believe I'll just have to replace the cooler at this point.

4evrwyntr · 10-19-2005, 11:05 AM

You should just replace the cooler in its entirety. That system is so prone to cracks... You probably have a couple small ones. It's not too expensive if you DIY and can get the part for manufacturer's...