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Heater core problem

I have an otherwise excellent 1994 chevy suburban with 110,000 miles. I have replaced the heater core five times with a very good repair shop. They can’t get the core to not leak. It takes about 2 months and then I have the same problem. A leaking heater core.

Find a reputable experienced independent shop/tech as the ‘very good repair shop’ in my estimation doesn’t know what they’re doing. (Except how to clean out your wallet) Sad but true.

There is NO way you should have had to replace the heater core 5 times.

Like I said, take to someone who knows what they’re doing. You need a different supplier too.

I’m Just A Bit Curious. Does Each One Leak At A Similar Location, By Chance?

Have they done an autopsy on the dead cores to determine where the leaks develop? This information could lead to a solution.

I have seen many after market cores which have the inlet tubes attached at the core by a simple crimped collar and washer seal. ( most OE are soldered solid.) Too much wiggling and the crimp is loosened. We’ve seen installers bend and twist these tubes to get the core in and we’ve seen heater hoses flexing and wiggling in the engine area cause leaking at the crimped seal.
Is it an aftermarket core ? Is it leaking at the inlet tube to core seal ?

The most common reason for a new aluminum heater core to fail in a short period time is improper installation.

First, the vibration isolators have to be installed properly to the heater core to prevent the heater core from coming in contact with any hard surfaces. Otherwise a hole can be worn into the heater core from vibration. Also check the isolators for wear. If worn, replace them. Second, when installing an aluminum heater core, one has to make sure that it isn’t binding in it’s mounts. Aluminum heater cores expand and contract as they heat up and cool down. If the heater core is wedged into it’s mounts this doesn’t allow room for the heater core to expand as it heats up. And this can result in a cracked heater core.

Tester