63 HARDTOP
I am wondering what's the easiest way to tell if my heater core is bad. The car hasnt been driven, engine is out being rebuilt, so i am now removing the heater core and wanted to know if there's a sure sign its bad, besides rust or whatever. Should there be no leaks whatsoever if i run water through it? Should I just replace it with a new one anyway? All replies appreciated!!!!!!!!!

As long as your engine is out, your taking the core out, might just as well put a new one in. Best to do it now, then in 6 months after your car is back on the road.

It is actually very easy to tell if it is bad. You will see green green green and other copper discolorations in fins. Also should notice water stains in the bottom or sides of the heater core box. As far as just slapping in a new one IMHO I would inspect it like any part and use your best judgement. There has been more than one defective core out of the box and that type of product is being sourced in Mexico, China and who knows where else. Good Luck!!

Terence,

You have a reply on how to tell if it is leaking. If your question is how to tell if it clogged; the first sign is you get no or little heat. If the car wasn't running when you got it, then you need to do a simple flow test. Put your heater hoses back on and connect in a hose. Turn on the water and gauge if the volume going in is coming out.

If you have the thing out, you might consider taking it to a radiator shop. They will "dip it" to make it as clean inside as possible and then pressure check it for very few $.

Good Luck, Vince

I appreciate all the help, had a friend check it out and told me, its best just to buy another one. Leaking residue very noticeable!

Good decision IMO. I am in the process now of removing the heater core from my '66. It is in unknown codition and I don't want to get the car back together and have this thing leaking all over new carpet and other parts.

Have fun with your T'bird.