On Mar 20, 6:24*pm, jon_banquer wrote:
On Mar 20, 6:04*pm, Ed Huntress wrote:









On Wed, 20 Mar 2013 19:59:49 -0400, wrote:
On Wed, 20 Mar 2013 11:49:22 -0400, Ed Huntress
wrote:

On Wed, 20 Mar 2013 08:42:16 -0700, "PrecisionmachinisT"
wrote:

"Ken Grunke" wrote in message
...

I am assuming there has to be a separate check valve INLINE between the
plug adapter and the gauge below the release valve. That is what I am
missing. It may be a fitting I had, but absent-mindedly misplaced.

Could be a spring and or check ball is missng or gunked up at the spark plug
fitting end...

--FWIW blowing into the end with your mouth probably won't produce enough
hose expansion to actuate a ball type check valve.

Sorry for jumping into the middle without having read the thread, but
there are two kinds of compression testers: the regular kind, which
have a button to activate the check-release valve; and leak-down
testers, which have no such valve.

I have both. They look almost the same. Perhaps, if Ken's tester
doesn't have a check valve, he has a leakdown tester. If so, it will
have a spark-plug-thread terminal end. Regular testers *may* have such
a thread. Mine just has a tapered rubber plug.
*A leakdown tester should have 2 guages and WILL have a connector for
compressed air.

Mine has one gauge. It's around 45 years old. And as I noted in an
addition to the post above, it has a Schrader valve for pumping up the
cylinder.

What's the second gauge for? With mine, you just attach it, make sure
both valves are closed, and pump it up. Test dry, then test wet (with
about an ounce of oil in the cylinder; more for a V-engine).

Is there something else that I've missed?

--
Ed Huntress

One gauge tells you your air input pressure, the other your cylinder
pressure.

It's about doing a comparison. You're always going to have a
percentage of leak and you want about the same percentage of leak for
every cylinder.

Watch this. It's a well done video:

http://www.youtube.com/watch?v=QNf0IOIvIcY