flushing a blocked heater core

[Chief Brody]

ok...this is on my Ford Ranger, but have any of you ever flushed out a clogged heater core?
The whole dash has to come out to replace it...I'm not doing that right now.

Can you do it with a garden hose and how do you know which direction the flow should go so you don't lodge the debris further in?

 

[British Slave]

You want to back flush it. You can get a flusing kit for a few bucks at Dumbo Zone or even Wally World. The large hose is the inlet. Using the kit, install the fitting, hook up the garden hose and disconnect the lother hose and turn the water on. OR you can read and follow the instructions with the kit.

 

[sweetk30]

i just pull both hoses so the junk dont go back in the block .

then extra section of heater hose to each nipple and garden hose and go back n forth till clean and clear.

done this so many times for people over the years. just did a s10 today

 

[79rustyk10]

I was told by an old timer, to flush them by alternating from inlet to oulet until the water came out clean.

Damn you beat me.

 

[Chief Brody]

i'll give that a try when it isn't 33 degrees and raining slush

 

[sokoloka]

My buddy who does this on the regular likes to run some CLR through the heater core as well to loosen up any crud. Not done this myself so I don't know how good the advice is however.

 

[Chief Brody]

My buddy who does this on the regular likes to run some CLR through the heater core as well to loosen up any crud. Not done this myself so I don't know how good the advice is however.

I might try that, but my suspicion is that it is the aluminum powder I put in my old busted radiator before I changed it. I think thats what killed the thermostat as well.

I wonder if flushing will get aluminum powder out of the heater core? Does the powder just remain loose and "gather" where there is a leak or does it set like cement?

 

[sweetk30]

just garden hose flush it . it will work or not.

and if you even need sealer basic old bar's leak in gray bottle NON pellet formula .

 

[putt putt diesel]

I just flushed the heater core on my 1983 K5 today with directions from "Ericthecarguy" on youtube. Drained radiator to a level below hose connecting to engine, disconnected hoses at rad and block, drained hoses in a bucket under Blazer, left the in hose pointing toward bucket and used an open air fitting at the hose end of air tank, blew coolant from tank with 40 psi. Lifted both hoses and squirted a 13 oz bottle of generic calcium remover in top hose. waited one minute then wedged in line toward bucket, and flushed with a garden hose alternating directions, and then blew water out of core. Then reconnect hoses, and refill radiator. I didn't get any chunks out, just whitish colored fluid. The heater works much better now!!