Heater core test

[Michael G.]

Is it advisabe to exceed the normal operating system preasure when testing a new replacement core prior to installation. I know these don't go in without a bit of a fight and thought that a little extra preasure would prove it's worthy of the battle. Any thought would be helpful. Thanks, Mike

[Joe L.]

Re: Heater core test

Is it advisabe to exceed the normal operating system preasure when testing a new replacement core prior to installation. I know these don't go in without a bit of a fight and thought that a little extra preasure would prove it's worthy of the battle. Any thought would be helpful. Thanks, Mike

Mike-----


I would not use more than 20 PSI to pressure check the heater core. In fact, I really think that checking it at 15 PSI is adequate and is what I would use.

[Dick W.]

Re: Heater core test

When I owned a radiator repair shop, the most pressure we would use is 18'. This is about 10-20% more pressure than you would experience in normal operation

[Michael G.]

Re: Heater core test

Excellent advice as usual. I can always count on you guys to keep me from doing something stupid. Always grateful for the guidance. Thanks, Mike

[Robert S.]

Re: Heater core test

Mike - I am at about the same point on my 74' as I think you are and will reinstall my new heater core when it gets a little warmer in CT. I had the same thought and concern about a preinstallation test. I did take the new heater core to a radiator shop to test it and it was good but they thought the tubes to core solder joints were a little marginal and they resoldered it to provide some added strength. I am not sure whether the new core needed this rework but given that I do no want to do this job ever again, I thought it was worth the small cost. I plan to install the heater core/distribution box assembly, hook it up and use the engine to do a final leak test before I start to put the interior duct work and center stack parts back in (my car has AC).

I was wondering whether you had to do any material removal of the pot metal plate (ie the plate to which the heater core is attached by two straps) to get the heater core installed on the plate and ready to go back into the distribution box - I had to do more rework to this plate than I had anticipated and was curious if others are experiencing the same problem. If you had to do any rework to the plate could you describe what you had to do?

[Duke W.]

Re: Heater core test

Check with a radiator shop, but IIRC they might use about 30 psi to stress the core.

Duke

[Michael G.]

Re: Heater core test

Robert,
I am not in the disassemble mode yet and I was not aware of the plate reworking. I appreciate your input on that. Sorry I can't add anything on the plate issue. As far as the inlet/ outlet tubes, I don't think that you wasted any money there as I have followed posts that mention having to slightly stress these tubes during the installation. I may consider beefing up these joints as well. Thanks, Mike

[Michael B.]

Re: Heater core test

Here is a little trick for testing heater cores.

Purchase a small bicycle tube and cut it in half opposite the valve stem. Clamp the two open ends on the heater core outlets and add some air. If you are going to do any damage it will be to the tube but you should be able to get a few pounds of air in there and let it sit. There should be no loss of air.

[Larry M.]

Re: Heater core test

Typical industry practice is to test at 1.5 X MAWP (Maximum Allowable Working Pressure). Assuming the MAWP is 15 psig, then you should test at 22.5 psig.

I would leak test the heater core at a nominal 20 psig.....and be very satisfied if no leaks were found at this pressure.

Larry