Last week I asked about pressure testing my coolant system. I have a Stant pressure tester but was having trouble finding an adapter for our overflow tank. Stant has a bayonet connector, we need a threaded connector.

The other day I saw a coolant pressure adapter designed for Jaguar XK at Amazon and jumped in it. This was too good to be true, an adapter for $45 that screws right on! I couldn't resist it.

I must have forgotten TestPoint's great advice from the day before: "Those that screw on the reservoir don't seal the vent to the atmosphere overflow tank."

He sure is right, this thing screws on perfectly, but can not build any pressure at all. You can hear air leaking out with every pump. I squeezed the upper coolant hose, sure enough same air leak. Just to test it I put the cap back on the overflow tank and gave it a squeeze - nothing.

Well lesson learned and I hope this post will help someone else. Now that I have a connector of some sort, it would sure be nice to do a pressure test.

Is there any way I can somehow work around this and plug that vent to the atmosphere on the overflow tank so I could pressure test this today and get it over with?

I appreciate any thoughts you may have. Testpoint - thanks for the spot on advice. Guess you can't think "if Amazon says it will work, this must be true" (laugh at myself)

John

 

My Harbor Freight test kit has a screw on that seals the tank.

 

John,


Rather than removing wheel & wheel arch liner to get access to the tank, can you clamp the pipe that goes from the reservoir to the tank - I think it's the one at the rear - can't remember exactly without going out to look but it will be obvious.

 

I might just try that. Will have to see how brittle it is.