How do I perform a Leak-down Test?

[joseph.signore]

Dose anyone know how and what tools needed??? I have a 5.7 Merc Alpha.

 

[JustJason]

Re: How do I perform a Leak-down Test?

its easy.... first you buy a big compresser... the bigger the better.... then you buy a leakdown tester..... then you google "leakdown test"


what's your problem?

 

[joseph.signore]

Re: How do I perform a Leak-down Test?

I'm getting raw water in all four of my port side cylinders and water in my oil. I have a 1991 5.7 350 magnum Alpha one mercruiser. I changed my risers, exhust manifolds and checked for blockage out to the stern drive and still have the problem. the moter runs fine with no skip however when I shut the motor off the cylinder fill with water again.

 

[JustJason]

Re: How do I perform a Leak-down Test?

what brand of risers/manifolds did you buy? where they new or used? did you check the mating surfaces for flatness? did you put the gasket on dry or with some kind of sillycone?

 

[joseph.signore]

Re: How do I perform a Leak-down Test?

Mating serface look good no paint... I used all OEM Merc Cruiser parts and gaskets, all brand new. I had this same problem with the old manifolds and risers, after replacing them, nothing changed. I did not use any silicone sealant anywhere, just the merc cruiser factory gasket. The reason I changed the exhaust manifolds and risers was because they were looking old and I thought they may be the problem. Again, changing them has made no difference at all. I am now worried about water doing damage to my engine, I've been constantly changing the milky oil after testing and fogging the engine and cylinders