Re: how to perform a leak down???

[Street Bugs <strtbug@ibm.net>]

>From: vince_pappalardo@om.cv.hp.com
>X-Openmail-Hops: 2
>Date: Wed, 11 Dec 96 10:49:26 -0800
>Subject: Re: how to perform a leak down???
>To: strtbug@ibm.net
>
>Item Subject: how to perform a leak down???
>
thanks Vince it seams every one else that replied didnt understand my
question and basically told me how to do a compression test. i just want to
find out if i need to rebuild my heads or have a bad head gasket or bad
rings. now i can go play with my 86 vanagon Later Jonce

     
>     Hi Jonce,
>     
>       The quick connect compression tester and air compressor are the 
>     proper equipment to perform the leak down test.  As for the pressure, 
>     the engine normally develops around 140psi.  So, it is well capable of 
>     these types of pressures before the pistons will move.  I would 
>     recommend setting the air compressor around 90 psi.  The is typical 
>     shop pressure and is more than enough to detect where it is leaking 
>     from.  I have not done this test on a VW yet; but, I suspect there are 
>     no special issues on this engine.  By the way, the cylinder must be at 
>     top dead center and the valves must be closed--make certain the 
>     cylinder is on the compression stroke when at TDC.  With the spark 
>     plug removed, crank the engine.  The compression stroke is the one 
>     that pushes air out the spark plug port (sorry if this is old news to 
>     you but I thought I would mention it.)
>       As for weather to do the test hot or cold, I would perform the leak 
>     down test under the same conditions you performed the compression test 
>     that I presume lead you to perform the leak down test.  
>     
>     Regards,
>     
>     Vince.
>
>