Heater core failures scare me. Pulling a dash would not be fun! I've been thinking about a super flush of sorts. Here is my plan.

Pull hoses at firewall. Flush and backflush. Block off lower outlet with saran wrap and rubber bands or block hose.. Fill core with CLR and let it sit for hours. Flush and back flush again. Sounds good?

 

The day my core goes out is the day i dont have heat... LOL I'm not sure on the CLR I'd be concerned with what it does (for the long run) to the copper and stuff in the core.. I've seen what it can do to some soft metals and it's not pretty..

 

Copper pipes have all kinds drain cleaners run thru them, so I'm thinking it should be safe. Maybe I can shorten the time.

 

Do you have a heat problem or just upkeep? I have never had a problem with heat even when I lived in Southern California I even use regular tap water. I had an exploding rad problem till I started using a 40/60 coolant mix lost 3 rads in 6 years. Now I understand the problem was my efan didn't kick in till 210 I had an overheating problem in bumper to bumper traffic.

 

I have no issues and am trying to keep it that way. I do have nearly 260k on the clock and the previous owner wasnt the best at maintenance. Still heat gets volcano hot.

 

Regular maintenance will prevent many a problem from happening. Just use a regular cooling system flush, not CLR.

From the CLR website:

Can I use CLR to clean out my radiator?
No, CLR should not be used on a car radiator for two reasons. First, CLR may not be compatible with the internal metals of the radiator. Second, it could have adverse effects if the CLR is not rinsed out completely.

What will CLR do to copper or aluminum?
CLR will take the finish off of aluminum and copper.

 

Hmm... thanks for that. Scratch the CLR then. I used Prestone rad flush when i first got the truck. I saw gritty crud flowing out. Maybe i will use that or something else. Whatever it is, i will research it first. Oh, and i also replaced the radiator. Used distilled water and prestone green back then.

 

Reverse flush the heater core, and pay attention to what comes out.

If nothing much besides the water, I'd not worry about it.

Also, tap water left in the heater core, if you refill the rest of the system with distilled ater, should be OK as long as the water's not TOO hard.

Add to that, on some cars we need to ground the heater core to the block to prevent any electolysis from happening. Can't hurt to attach a ground clamp to the heater core tubing and ground to the block.

RwP

 

RalphP


That's a new one on me could you explain that for me as the heater core is basically isolated so I don't see what you are talking about. I'm a bit concerned as I just replaced my core and its aluminum not brass/copper.


Why do you need to ground it?

 

The engineers should have handled that and addressed it.

Ford even went so far to put out a bulletin a few years back that said:
“Do Not Ground Heater Core. If the heater core is grounded, you have provided the electrolysis a path through the heater core. This would cause the heater core to become an anode or receiver, and it would promote the electrolysis, or any stray voltage, to use the coolant as the ground path.”

If they find a voltage higher than 0.4 volts you are to check all the grounds and make sure they are clean. They then recommend a coolant flush.

The simple truth is metal corrodes. No matter what you do you can't prevent corrosion. Given enough time the heater core will corrode - even if it's just from the wear of the coolant circulating through it, think Grand Canyon. It happens to pipes and it will happen in your car.