Coolant pipe repair - now required for DE!
#46
02-11-2012, 04:31 PM
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#47
02-11-2012, 08:15 PM
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Join Date: Jul 2004
Location: Bay Area, California
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Rep Power: 49 We do not weld these fittings, however we have done many of these cars with the fittings pinned as described in this thread. I'm not sure of the number (maybe Alex or James can help w/ that), but I'm sure in the range of 30-50+. Some were done 5-6 years ago, many have over 20,000-40,000 miles by now.
Zero have leaked to date as far as I know.
A GT3 came in last week for a 3.9L upgrade. A well-known shop performed a coolant fix for his car. Their solution was to weld the fittings. The car has had around a dozen track days. When we took apart the car we found this:
Tiny pinholes in the welds, that were probably invisible at the time of completion, lead to leaking coolant.
Every Shark Werks 3.9L, every 996 / 997 Turbo engine we've built since 2005, and many cars that dropped in for this repair are running the pinned pipes and none have leaked yet that I'm aware of. There are several Rennlist members who might not even be aware of how we do the fix and just about all are taken to a track.
Zero have leaked to date as far as I know.
A GT3 came in last week for a 3.9L upgrade. A well-known shop performed a coolant fix for his car. Their solution was to weld the fittings. The car has had around a dozen track days. When we took apart the car we found this:
Tiny pinholes in the welds, that were probably invisible at the time of completion, lead to leaking coolant.
Every Shark Werks 3.9L, every 996 / 997 Turbo engine we've built since 2005, and many cars that dropped in for this repair are running the pinned pipes and none have leaked yet that I'm aware of. There are several Rennlist members who might not even be aware of how we do the fix and just about all are taken to a track.
I know the above mentioned car owner and repair shop. Prior to the repair I suggested the shop pin the joints rather than weld them. The shop owners response lead me to believe he was looking out for his own interests rather than the best interest of the customer. The labor cost to clean and weld all the fittings exceeded 1k.
#50
02-12-2012, 03:02 AM
I think I'm going to try and get mine pinned this week actually. Contrary to the antagonists of pinning, I haven't seen any evidence of pinning going wrong, but from here and the GT3 boards on Rennlist, I have seen at least a few instances of welded fittings leaking and being troublesome.
And what happens if the welds leak over time, another load of money to drop the engine and repair because you can't repair a weld with the engine in the car can you?
And what happens if the welds leak over time, another load of money to drop the engine and repair because you can't repair a weld with the engine in the car can you?
#52
02-12-2012, 08:18 AM
One problem with welding them is the coolant manifolds are cast. Welding to any cast metal fixture can pose it's own set of issues. And aluminum is very sensitive to contamination when being welded. No matter how much you clean aluminum, a cast aluminum piece will have very small little voids for contaminates to live that can be sometimes impossible to clean out. Pinning would be the ideal fix in my book if the piece has not already come loose. Re-gluing and pinning seems like the fix if they come loose. I am not sold on welding for the above reasons.
#53
02-12-2012, 08:55 AM
Welding is the only absolute fix, problem is this needs to be done by an expert at welding aluminum. It also should be pressure tested but a pinhole leak will easily be fix with a quality radiator stop leak additive. Pinning may keep the fitting in but the real problem is the glue, which will still allow a leak.
#54
02-12-2012, 09:39 AM
I agreee that welding is the best absolute fix, you just have to be sure there are no pin hole leaks before reinstalling. If it doesn't leak, it never will. Pinning does seem a lot easier and will probably last forever, although it is possible a pin can get loose, at which point it is no longer pinning or in a worse case vibrate loose and spring a leak. With a proper weld, failure will just never happen.
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991.2 GT3 RS Weissach Racing Yellow
991.2 Turbo S GT Silver
991.2 GT3 Chalk (Manual)
2022 Cayenne White
former 1972 911T white, 1984 911 3.2 Targa black, 993 cab white, 993TT arena red, 993TT silver, 996TT speed yellow, 991.1 GT3 white
www.speedtechexhausts.com
info@speedtechexhausts.com
Testimonials facebook SpeedTech Exhaust Videos
#55
02-12-2012, 09:41 AM
Glue does not just give unless aadditional things like movement and heat initiates it. Pinning it stops it from moving or giving. The glue itself remains intact once the movement of the fitting is eliminated with the pin.
#57
02-12-2012, 01:01 PM
Problem is they look like a ***** to pressure test because of all the different holes in the piece but if someone wants to send me their part and have some time on their hand, i can try to build something to pressure test the welds before putting them back on the car.
Otherwise, i will be making a kit next winter when i do mine and it is sure that i will weld mine, no way i will only use the pin method as when the glue gets bad, it will leak anyway, not blow but still...
Otherwise, i will be making a kit next winter when i do mine and it is sure that i will weld mine, no way i will only use the pin method as when the glue gets bad, it will leak anyway, not blow but still...
#58
02-12-2012, 01:25 PM
It would be nice if someone had a few of the coolant manifolds available already PROPERLY welded + LEAK TESTED and ready to ship on an exchange basis with a core charge. With more and more of these ticking time bombs out there it could a lucrative deal for someone. This could be handled basically like John at Speedtech does it with the modifed OEM turbo intake manifolds. I think many people (including myself) would like to get this done but want it done CORRECTLY the first time with little down time. If I could have a set of the welded manifolds in my possession I would just drop off my car, get the engine dropped, coolant manifold swapped out and then just stick the old ones in a box and ship them back. Simple......
#59
02-12-2012, 01:29 PM
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Join Date: Mar 2008
Location: Montreal Canada
Age: 69
Posts: 2,804
Rep Power: 266 It would be nice if someone had a few of the coolant manifolds available already PROPERLY welded + LEAK TESTED and ready to ship on an exchange basis with a core charge. With more and more of these ticking time bombs out there it could a lucrative deal for someone. This could be handled basically like John at Speedtech does it with the modifed OEM turbo intake manifolds. I think many people (including myself) would like to get this done but want it done CORRECTLY the first time with little down time. If I could have a set of the welded manifolds in my possession I would just drop off my car, get the engine dropped, coolant manifold swapped out and then just stick the old ones in a box and ship them back. Simple......
#60
02-13-2012, 08:15 AM
The Shark Works fix will be accepted by OVR not only as an alternative to welding but a better approach. It is interesting to see that it is not just the pipe behind the power steering pump that fails but also one behind the alternator. Have any other tubes actually failed? We have had 3 failures , all on '04 GT3 cars and all were the pipe behind the PS pump.