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  1. #1
    Buaidh No Bas howestek's Avatar
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    Case Leak Frustration/Question!

    I rebuilt my wifes stock gp800 about 4 weeks ago and pressure tested it. It had a few small leaks (crack in pulse fitting and too loose pressure test fittings). I fixed them and retested several times successfully to 9 psi.

    Yesterday, I took the exhaust manifold off and pulled one powervalve to compare it to a new one. Put everything back together and retested.
    Doh!!!! There was a leak at the rear seal, between the seal and crank mating surface. I rotated the crank several times and retested. The leak was gone cept for a very, very, very tiny bubble that would appear, but wasn't enough to drop the pressure down after 10 minutes (at least on the gauge). I retested 5-6 times with the crank in different positions, with no perceptable loss in pressure. Once or twice there was a small bubble after 10 minutes that would grow no larger, but pressure remained steady.

    Question: a) Has anyone seen that happen?
    b) Opinions as to the neccessity of breaking it all back down and resealing on a stock engine?

    Thanks, Steve


  2. #2
    Happily Self-Employed WFO's Avatar
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    There was a leak at the rear seal, between the seal and crank mating surface. I rotated the crank several times and retested. The leak was gone cept for a very, very, very tiny bubble that would appear, but wasn't enough to drop the pressure down after 10 minutes (at least on the gauge). I retested 5-6 times with the crank in different positions, with no perceptable loss in pressure. Once or twice there was a small bubble after 10 minutes that would grow no larger, but pressure remained steady.
    IMO your fine.

    I am doing a 1200 now that shows some leaks at the rear seal. It slowly leaks down and holds 5psi for about 10 min.

  3. #3
    Duke's Avatar
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    Quote Originally Posted by WFO View Post
    IMO your fine.

    I am doing a 1200 now that shows some leaks at the rear seal. It slowly leaks down and holds 5psi for about 10 min.

    I agree. If your holding 9psi for 10 min then thats golden!

  4. #4
    Buaidh No Bas howestek's Avatar
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    Thanks, guys. I was just a little concerned as to why it would momentarily leak 4 weeks later, then heal itself. It dropped several psi until I rotated the crank. I couldn't get it to leak after that.
    Hopefully I can finish it up now so the wife unit will let me start devoting more time to the 1300.

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