Leaking Heater Core

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Q.

My 1963 Chevy Nova is almost restored. New carpet was just installed. I replaced the heater core once and it leaked on the old carpet after 4 years of use. Is there any place that will repair old cores? Can’t have a supposedly new core leaking on new carpet.

A.

There was a time when virtually every town had a shop dedicated to radiator repairs, and yes they would often do heater core repairs as well.

Over time the cost of replacement radiators has come down, so much so that in many cases it is much cheaper to buy new than to repair.

In doing a few quick internet searches for your car, it revealed heater cores were available in both aluminum and brass/copper, and could be had for as little as $30 and as much as $150.

There are times when no one makes a replacement heater core, in those events I would seek out a radiator repair shop that still makes radiator repairs, and they will have the skills and equipment to make the repair.

I recently had a radiator repaired, and while it took a few phone calls to find the right people to work on it, the reward was having a first rate job personally backed up by the shop owner with a promise and a handshake.

Because your car is so popular I would strongly recommend purchasing a complete new heater core. As repairs to your existing one will likely exceed the purchase price of a new one.

Wrench Safe,
Mark

Discussion
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13 Responses to “Leaking Heater Core”
    • Customer Service

      Hi Dennis,

      You’ll find guys that will argue this all day long. For a heater core you should likely choose aluminum. It has excellent heat transfer and will resist corrosion.

      Thanks,

      Mark
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  1. HDMania

    Hopefully the leak is near the outside where you can get at it..if your on a budget clean the metal down to bare metal and use some bondo..I fixed a radiator that way after an accident and the fix is holding and its been 13 yrs now..

    Reply
  2. wbrunner23

    My son had a coolant leak in his 2000 Chevy Monte Carlo. No puddles to tell where the leak was, but the coolant level kept getting low. He put K-Seal into the cooling system and the leaking stopped.

    Reply
  3. William Draper

    If you can’t find a heater core radiator shops (if any still exist) can repair them.

    Reply
    • Customer Service

      Hello William,

      There are still some “Old School” radiator shops around, that can repair heater cores and radiators.
      From my own experience radiator repair shops are getting harder to find but they’re out there.
      Many “modern day” radiator shops, simply replace the heater cores and radiators with new ones and often even lack the equipment to make actual repair.
      If they don’t have a new radiator or heater core for your application, you’re simply out of luck.
      So if your find an actual radiator shop that can make repairs, be certain to support them so they’ll be there when you need them.

      Wrench Safe,

      Mark
      Classic Car Restoration Club Video Membership

      Reply
  4. Scot

    The guy at the radiator shop says you need to leak check a new heater core before you install it because of the high failure rate.

    Reply
  5. Aaron

    I have a 58’ Impala which after 10 mins or so begins to blow steam on the windshield. Where is a good place to start? Can I fix it without replacing it?

    Reply
    • Customer Service

      Hi Aaron,

      Thank you fro your patience, here is the response from the expert:

      I believe the problem is a leaking heater core or heater control valve, as It is not uncommon for either of them to fail.
      Check the carpet and under the dash for wetness to discover the source of the leak.
      They reproduce Heater cores for your car and are available from many online sources for about $200.
      Likewise the new Heater Control Valves are about the same price.
      You could pull heater core out, take it to an old school radiator shop and have them boil it out and repair it, but it will likely cost near the same with no guarantee it won’t start leaking again in a few months. Also the heater control valves are rebuildable but not easy to do so.
      In a pinch, to stop the steam you could take the heater off-line and route a short piece of heater hose between the two connections on the engine.
      This will keep you running and attending car shows / cruise nights until you source all the parts you need to make the repair.
      Wrench Safe,
      Mark

      Classic Car Restoration Club

      Reply