Leak down test results?

[Toolanddiemaker]

Well I just got done doing a leak down test on a rebuild of my 657 and I'm getting some noise around the center of the jugs at the base gasket I sprayed some soapy water in that area and right away I could hear it bubble basically it's not holding any pressure it drops pretty fast I would say within a minute or so I used a wsm gasket kit that came with my top end from full bore. Is this a common problem, should I have put 3 bond down along with the base gasket? I'm a little lost on this,sucks I have to tear everything down. Any suggestions thanks in advance?


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[speedtkt]

I just re sealed my crank case cause of a leak now im thinking to pull the jugs and apply some sealant after reading this

 

[Toolanddiemaker]

Well I took the jugs off put a new different base gasket on and put a small film of 3 bond on the crank surface and torqued to spec and it stopped the leak


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[racerxxx]

I ALWAYS put a thin film on my base gaskets. I have already had an air leak kill an engine. I will take EVERY safety precaution I can. Literally just enough to make it shine.

 

[Toolanddiemaker]

I ALWAYS put a thin film on my base gaskets. I have already had an air leak kill an engine. I will take EVERY safety precaution I can. Literally just enough to make it shine.

Yep that's what mine looked like after I redid it. Man am I glad I made those leak down test plates well worth it! I found another leak after I retested at my oil block off plate so I put some three bond on that gasket as well problem fixed! I did get some bubbles on the carb gaskets I usually use this gasket material that I bought but I couldn't find it so I just used the gaskets from sbt do you put any dressing on the carb gaskets?








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[racerxxx]

Honestly, I don't remember if I used 3bond or a light coating of grease or both (3 bond on the carb side and grease on the RV side. When I pressure test I have the later thick gaskets on for the test.

 

[Toolanddiemaker]

Honestly, I don't remember if I used 3bond or a light coating of grease or both (3 bond on the carb side and grease on the RV side. When I pressure test I have the later thick gaskets on for the test.

Cool thanks Racer I will do some research.


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