Heater Core Testing

[Kurt B.]

Is there any way for a do-it-yourselfer to test a heater core at home for the sake of expediency using water pressure or air pressure before installing a new heater core on a 68 coupe with A/C?
I don't want to take the time to send to a shop and wait and the last shop spoiled my original 68 radiator so confidence level in repair shops is a bit low.
I have heard that some new cores can leak right out of the box and that it is wise to test before installing and I have everything apart and want to test the new one before I install. I don't know how much pressure is normal for the system and so don't want to use high air pressure and blow it apart. Can I rig something up to test this core before I install it. Only have body on frame so can't hook up heater hoses and run engine as it is out of car at machine shop.
Thank you for any suggestions,
Kurt Bunting # 26406

[Jim T.]

Re: Heater Core Testing

Kurt I believe you are still in the process of getting your car restored and the engine is not ready to operate, but if it is, you can connect your new core to your heater hoses before you install the core in the car and test it. You could also connect it to another car/trucks heater hoses.

[Clem Z.]

Re: Heater Core Testing

i have used air pressure and my wifes laundry sink to test them. set you air compressor at 5# and work your way up to 15# while the core is under water. you will need to plug 1 of the tubes and and make some type of connection for the air supply.

[jim34671]

Re: Heater Core Testing

Hey Clem,
I knew there was a reason for the wife's laundry sink!
The coffee table is also a great place to do a Quadrajet overhaul!
Hee Hee!

[Christopher R.]

Re: Heater Core Testing

What pressure is your cooling system designed to work at? That's the number of lbs/sq.in on your radiator cap - probably 7 - 15. Test it at 20 lbs/sq. in of air pressure submerged in the laundry sink.

[John D.]

Re: Heater Core Testing

Kurt:

By now you know what a pain it is to pull the heater box out of a 68 with air. When I had mine out I took it to a radiator shop and had it pressure tested. They told me it should hold, but I kept looking at the work involved getting to remove the core. I shopped around and found a reproduction core for about $65.00. I put the new one in because I was told the corrosivity of antifreeze can weaken a core in a short time, even thought it held pressure.

Another 2 cents is to replace the firewall insulation if it is in rough shape,. I wish I had.

John

[Myles Kukurudz]

Re: Heater Core Testing

Hi Kurt,
I used a bicycle tube and some hose clamps, blocked one end with a plain rubber piece and positioned the valve section over the other tube and clamped it on. Worked great for me

Regards
Myles