Changing the coolant breather valve

[Andrew McD]

Sorry Dale, but on a different note, what is a tiptronic service?

Mine is a 1999 and the tiptronic is getting a bit lumpy.

[Dale_K]

The Tiptronic service basically means draining the fluid in the pan, dropping the pan, changing the filter and refilling the fluid, per the 101 projects book. Possibly draining and refilling a second time to get a more complete fluid replacement. I think it's supposed to be done at around 80k miles. My car displayed a CEL for a vacuum leak but there was a 0740 code too, which has to do with torque converter clutch operation. It shifted a little funny going up hills under light load when cold. Worked OK after it warmed up. I'm hoping the fluid replacement will fix it but it might need a new torque converter.

[Dale_K]

I have some more information and pictures about this operation. I was confused because I didn't see any o-rings when I removed the bleeder cap.



The cap



Some of the posts made me think that maybe some tanks didn't have o-rings but I finally managed to wiggle the part with the 8 bolt holes and realized it was a separate piece. It's hard to pull out but I got some big channel locks on it a eventually wiggled it enough to get it out.



Below are pictures of the tank with and without the o-rings.




O-rings don't seal by vertical compression like a gasket. They are squeezed between the OD of the male part and the ID of the female part. I could feel the old o-rings had become kind of square shaped and might not seal anymore. I have a feeling that some of the threads about condensation on the trunk lid near the coolant fill are due to these o-ring seals.

I visited the hardware store and got some generic o-rings since the Porsche parts place didn't include the genuine ones in my order even though I specifically added them to my online cart. They did give me a credit for the unshipped items.

I haven't driven the car yet but the housing felt good going together over the hardware store o-rings some I'm hopefull.

[rkporshe]

"Some of the posts made me think that maybe some tanks didn't have o-rings but I finally managed to wiggle the part with the 8 bolt holes and realized it was a separate piece. It's hard to pull out but I got some big channel locks on it a eventually wiggled it enough to get it out."

I am exactly at this stage wondering what to do next. took out the 8 bolts and the cap. Any additional info is appreciated. Did you use any tools to get the bottom housing of the bleeder cap to come out?