Changing the coolant breather valve

[insite]

sorry to hear your tank is dead. thx for the info that your kit came w/ an o-ring & not a square ring. looks like the factory thinks either solution is ok here. take care.

[shlim8]

Dale, just in case u need it - the size of the O rings are listed as 17 x 4 and 47 x 4 (I presume in mm).

I'm now enjoying a stable 80-85 degree celcius coolant temp.... (with the LN lower temp thermostat). It used to spike up to 90+ even with the lower temp thermostat... guess I was losing coolant pressure.

[Dale_K]

Originally Posted by shlim8

Dale, just in case u need it - the size of the O rings are listed as 17 x 4 and 47 x 4 (I presume in mm).

I'm now enjoying a stable 80-85 degree celcius coolant temp.... (with the LN lower temp thermostat). It used to spike up to 90+ even with the lower temp thermostat... guess I was losing coolant pressure.

That's good to hear. My car is in the shop for a vacuum leak fix and a Tiptronic service, so I haven't checked it. Part of the trouble with buying an old car is you don't know what things are supposed to look like or whether somebody left out parts in the past. I'm not even sure my car has the o-rings at all. I sure didn't see them when I removed the bleeder valve cap but I didn't take out the circular disc with the holes in the center.

[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?