I made a tester by using an old cap. also.  I removed the
valving in the cap, so that air would easily go in.  I then added a
hose from the cap to my air compressor.  This can easily over pressure
the system, so you have to be careful.

            Eric                   86-VW4x4
            vw4x4@fyi.net          86-SS Syncro
            Pittsburgh, PA USA     1936-Chrysler
                                   92-Jetta GWC
            www.fyi.net/~vw4x4/vw4x4.htm

On Thu, 30 Dec 2004, Ken Wilford wrote:

> I agree with RC on this one.  I bought a coolant system pressure tester
> from Sears (Craftsman) and I love it.  Pressure test and bleed the
> coolant system without the van running!  Awesome!  It lets us know that
> when a van leaves here there are no coolant leaks large or small.  It
> was under $100.  The only thing I had to do was to fabricate an adapter
> for the Vanagon expansion tank.  We did this by taking an old expansion
> cap and then cutting it so that only the part with the threads were
> left.  You screw this ring onto the tank and then clamp the tester onto
> it.  Works great!
>
> We usually pump the pressure up to 17 psi and then let it sit.  If there
> is a weak point in the system you will hear hissing, the pressure will
> start to drop and there will be leakage.  Do it cold as this is
> everything at it's loosest.
>
> Hope this helps,
> Ken Wilford
> John 3:16
>
> Robert Cardo wrote:
>
> >Would you like to locate the weakest area in  your cooling system fast?
> >
> >Chase down a Snap On dealer and purchase a expansion tank adaptor, and
> >the testing pressure pump.
> >
> >Best and fastest way to a resolve.
> >
> >I have this set up and t will find the leaking, or weakest point in the
> >cooling system very fast, and efficiently.
> >
> >There is no better way to accomplish what you have to do.
> >
> >RC
> >
> >
> >
>