replaced heater core.......already leaking.

ebk06

Member
Feb 23, 2007
113
12
18
so I replaced the heater core today and went to test and did a quick test drive. When I got home a few minutes later there was coolant leaking out of the weep hole on the lower passenger side firewall. Did I get a defective core or is something else going on?
 
  • Sponsors (?)


I think it has to be a problem with the heater core if it's leaking out the weep hole. That sucks big time. I just finished installing my new stroker and ended up wrecking my heater core as well. I still have to replace it. Good luck.
 
When you get the new one, check it for leaks prior to install. The welds are not so good on many. There's prolly a dozen different ways to leak check them but I think the easiest is to just cap both ends, boil a large pot of water, turn the heat off, drop the thing in, and look for a steady line of bubbles to come up.
 
Thanks Daggar Ill be doing that tomorrow for sure. I searched a ton of threads before doing this I wish I would have seen that suggested in one of them. Oh well you live you learn. I agree 347 I'd gladly pay $50+ for a heater core that would last for at least 5-10 years. The only good thing that came out of removing the dash today was it made replacing my speedo cable a breeze........come to find out my speedo gauge is bad as well as was the cable. A very unproductive day was had today.
 
core

I seem to remember that all heater cores are not created equal, I'm sure someone will correct me if I am wrong, but cheap autoparts places sell lousy cores, I got mine from napa and its fine, a friend got one from pep boys and it wasn't.

Also I think there is supposed to be a restrictor in one of the heater hoses, the feed to the core I think.
 
Did you re-use the spring clamps on the hoses? If you did it could be that they are not sealing properly and the leak ends up in the heater box. I have had this happen many times and now I always use screw type clamps whenever I replace any heater core.
 
Yea I replaced all my radiator lines when I replaced my waterpump and the new heater core hoses came with a restrictor (heater core was previously bypassed until today so the hoses are brand new) and I also got all new clamps and made sure to get them nice and snug.
 
Handle the new heater core carefully when installing it. Many people have ruined perfectly good heater cores during the installation, usually trying to muscle them into place, or when putting on the hoses. You'd think a new core would stand up to a little abuse, but they don't. Rough handling can crack them.