Testing heater core

[CaptRandy]

BT7 Heater core box is mounted but the hose from water pump side is not connected. The hose from the block valve is connected and closed. Have never tried the heater core to be sure it will hold pressure. Is there a way to check it by putting water to the copper tube and checking the core inside to see if it leaks? Any ideas how to attach a water hose supply without TOO much pressure? Afraid the house water faucet has way too much pressure.

 

[Michael Oritt]

Randy--

You could start with air using a bicycle pump and a couple of adaptors/hose clamps to see if it holds pressure. If there is a leak you'll know right away and at least there would be no cleanup necessary.

 

[CaptRandy]

Mike, I will try that. I have a few tubeless tire valves that I may be able to insert one in a piece of heater hose and with hose clamps make it pretty tight and pump it up to about 10-12 psi and see if it holds pressure. Good idea. Thanks.

 

[Michael Oritt]

Randy--

Good luck, and should your core not hold pressure the easiest way to find the leak is using soapy water or windex spray along with a constant supply of low pressure air.

 

[steveg]

I bought one of these back in the '80s and it has been incredibly useful over the years on mine and friends' cars.
You can pressurize the system with a cold engine and catch some leaks that seal up when hot.

 

[roscoe]

10 to 12 psig is really quite a bit for your purpose. I would go for half of that and use a spray bottle with some soapy water. If there are leaks, you will likley see bubbles although listening with a surgical rubber tube to your ear would probably reveal all but the smallest leaks as well. I pressure tested mine when I did my rebuild and did find a pinhole leak in the pipe gping into the core. Soldered that but I've never usednit here in CA where I am.

 

[steveg]

The way the Stant tester works is you attach it to the radiator and pump the system up to 10 lbs. You watch the needle. If there's a leak anywhere in the system, the needle will lose pressure. If the needle remains stationary, you have no leak anywhere, including the heater core. You can do the same with your pressure cap.

 

[CaptRandy]

Mike, I fabricated a piece of hose with a tubeless tire valve and a hose clamp now I will put other end on the copper pipe and "inflate with the bicycle pump to see if it leaks down.
Jon-good point on pressure as cap is rated to 7 psi
Will let you know how it works. Thanks all.

 

[Bob_Spidell]

I bought one of these back in the '80s and it has been incredibly useful over the years on mine and friends' cars.
You can pressurize the system with a cold engine and catch some leaks that seal up when hot.

Steve, Does this tester have a cap that seals 'long neck' Healey radiators, or did you have to mod something up?

 

[steveg]

Steve, Does this tester have a cap that seals 'long neck' Healey radiators, or did you have to mod something up?

Bob - This is how I did it when I got the Healey 19 years ago. It comes with various spacers for longer necks. I always wet the gasket and it seals fine. The gasket isn't cracked and has never been replaced.