I have a GT28RS and the fitting for the oil inlet to the centre housing is leaking oil. The fitting is a cone type to AN adapter, supplied to me by Full-Race. The oil supply line is a stainless AN type and it is not leaking at the fitting. The leak is where the cone type fitting threads into the center housing. I have of course tightened it more than once and put standard plumbing pipe seal even though I am assuming cone type seal does not require any thread sealant, but it still leaks. The fitting and turbo are brand new and threads are all good. Cone type seal seat on fitting looks smooth as well. What can I do to fix the leak? Please help, dyno tuning this afternoon, and too much oil leaking to ignore it!

GT28RS oil inlet port





Modified by descartesfool at 8:20 AM 7/18/2005

 

Take off the pipe sealant on the fitting.

 

It should seal correctly if you use no sealant and tighten it down all the way...

If you have tightened it down without sealant already then maybe you have the wrong size fitting? I don't know why else it would be leaking.

 

Are there different size cone angles for the seal part. Is it possible angle on turbo is not the same as on fitting? I removed all sealant as I know it serves no purpose on the treads in any case since it is not tapered thread like an NPT. Seal should be via the cone-contact I am assuming. I tightened it a lot but I am afraid of breaking it if I torque it further. Would a high temp 700 degree silicone liquid gasket on the threads do anything? I don't have any other fittings to try as this is the one that came with the kit.

 

This is an inverted flare fitting, the same as is used in brake lines. It should not have thread sealant of any kind, and should be free of debris. It is possible that there is a mismatched fitting: Some IF fittings use o-rings and some do not.

 

Just spoke to Geoff at Full-Race today and he suggested using a softer brass inverted flare fitting as he has found in case of such troubles that the soft brass being more maleable mates better to the stainless flare in the center section. Hard fitting I have does not always fit well apparently. Might help the next guy out.