The wet test is different than a leak-down test.
>From the archives (Michael Ferguson I believe):
The Leak-Down Test
Using a special tester and a supply of compressed air, each cylinder is
pressurized. The rate at which the air leaks out of the cylinder, as
well as the sound of the air escaping, can more accurately pinpoint the
magnitude and source of the leakage. Any engine compression diagnosis
which will require major disassembly should first be confirmed by the
more accurate leak-down test. Because the test requires special
equipment and experience, it may be desirable to have it performed by a
dealer or other qualified repair shop."
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Subject: Compression test/"leak-down" test
Author: Pete & Aprille Chadwell <dynamic@transport.com>
Date: 02/18/1999 3:58 PM
Bud Rolofson wrote:
>A dry test can tell you: that you might have a faulty head gasket if two
>adjacent cylinders have low readings, or if the pressure builds up erratically
>(as you crank the engine) the problem could be burned valve seats or sticky
>valve guides.
>
>A wet test is done to help diagnose WHY your compression is low, it is not
>done
>to confirm low readings on the dry test.
>
>e.g. On a wet test, if the compression increases to nearly normal then the
>rings, piston, and cylinder (for that cylinder) are probably in need of
>service.
Is this "wet test" the same as a compression "leak down" test?
Can anyone describe how a "leak-down" test is performed and how it is
different from a "wet test" if it IS different?
I've done regular compression tests and I've got those handled just fine.
But these others have me a bit puzzled.
Thanks,
Pete Chadwell
1973 TR6
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