Pussywillow1972

I replaced the coolant pipes in my 06 CS as a preventative measure. The install went ok. It took longer to get the intake off than it did to remove the old pipes. I got the upgrade kit from Suncoast which included everything except the grease for the O-rings. I used all-purpose grease as that was all I had available and the parts department at the local dealership was closed for the weekend. I did clean the bores and got them looking fairly good prior to installing the pipes. I also used a very sparing amount of grease on the rubber hose joining the two pieces of the large pipe to get it on the large piece. After the hoses were attached to the three upper pipes and the coolant return line was installed, I used a uview airlift II to pull a vacuum. It pulls the vacuum quickly but when I see if it holds, it very slowly loses it. All the hoses get sucked flat with the exception of two of the three hoses on the upper pipes, (the one closest to the passenger side and the middle one).

Would the all-purpose grease be causing the O-rings not to seal compared to the Porsche grease? Would rtv on the pipes be an option to provide a better seal or is that not a good choice? Should those two hoses on the upper pipes also get sucked flat or are they too small in diameter? Any other places to look for a leak? Thanks for any insight.

Slow Guy

I do know on the official Porsche Workshop instructions it says to use the grease vary sparingly or it will cause leaks.

That's all I got for you. Best of luck.

XR4Tim

Did you remove the thermostat housing to get to the upper 3 pipes? If so, did you replace the metal gasket when you reinstalled it? Reusing the thermostat housing gasket will cause a leak. Otherwise, you may just have to pressure test the system and look for bubbles.

Pussywillow1972

No. I left the thermostat housing in place and just removed the pipes. As Bill stated above, using too much grease could cause a leak. I didn't use much, just enough to lightly coat the O-rings, but I wonder if I may have used too much even with that little amount. One thing I thought odd when doing the installation was the stub pipe went into the block with minimal force and I could rotate it very easily once in place. The longer piece of the large pipe required much more effort to get it in the block. I'll pull them out, clean them off, scrub the holes again and retry.

XR4Tim

Then that's where I'd look first. I don't recall ever doing one that didn't have to at least be tapped in with a block & hammer. Pull it out and make sure both o-rings are installed and are the correct ones.

Rickyuk

When I changed my pipes I was very careful not to damage the aluminum bores when removing the steel ring and plastic from the old pipes. If you catch them with a chisel the o rings may not seal. Also the correct type of grease is important as some types will eat the rubber over time. I used a synthetic grease. I did have to really apply a lot of force on the top 3 pipes to get them to fit so it is very easy to damage the o rings.

Pussywillow1972

I used the method of drilling a hole in the lower pipe sections and putting a screwdriver in there to rotate the pipe as I used a pry bar to lever it out. I didn't have to chisel at all. That idea was in one of the coolant pipe threads and worked beautifully. I took everything apart tonight and the top tubes and larger section of the lower pipe came out easily. The stub piece won't budge. I can wiggle it a little bit side to side but it won't come out nor can I rotate it. I'm guessing the seal is pretty good on that one at this point, or should I try to pry it out? My thought is to use some RTV to really seal the pipes in the bores. The O-rings looked good on all the pipes that came out. I'd hate to go that route and then find out the stub pipe is the issue and not have used RTV on that one because it wouldn't come out.

Slow Guy

You're welcome.

Did the chisel on one end (took forever) and figured there had to be a better way.

Rickyuk

The plastic pipes came out with no real issues. It was the metal sleeves in the bottom holes from the lower pipe that needed to be cut out. especially the one under the thermostat housing. The o rings are a tight fit so I am sure they provide a water tight seal.

69gaugeman

A pressure test is MUCH better than a vacuum test, as it moves the o-rings to the wall that seals.