How do you flush an old radiator?

totally agree. hard to dispose of that crap around here. I had overheating issues at the start of summer. would idle fine but got hot quickly when driving. had it flushed for $50 and there was a mouse nest from being off the car this winter. cured the problem

 

The Oxalic acid flush is availible from your local GM dealer. It's a 2 part package in one can...the flusk, and the neutralizer. It's called "Super Heavy Duty Cooling System Cleaner". Works GREAT...

 

I would trade in this radiator for a brand new one. There are several companies that make really,really good radiators now that supersede the specs of your old radiator. Jus my two cents. Mikey

 

29Nash, I'm with you on going the extra step to take OUT the thermoststat to do a good flush. With the exception of some agents 345 mentioned, I don't like to let the car sit all night. I'd rather get it done, even if it means missing a football game to mind the car while it runs. As you say, flush the system out TWICE, and put in a new thermostat.

But, it's just a pesky enough chore, I also do just what Sirweesarunch said. If you do add water, spring for distilled at 75 cents or a dollra a gallon. Then, remember to keep your mix right so the system doesn't corrode up again. Water alone, of course causes oxidation of metals.

 

AnchorBoy, I can understand if PoBoyRoss wants to recon the '50 radiator. But I had a minor question on your post: What brand of NEW radiator have you had the best luck with?

Last NEW one I bought and installed was a G.O./Daniels radiator. It turned out to be worth every cent I paid for it. That was a while back, so this company may have been subsumed by now by a BIGGER company.

 

When flushing an old radiator you'll often open holes. Over the ages radiators get pin holes and people add some stop leak to plug 'em up and that slows the flow like you described, when you get proper flushout you wind up with a radiator that has more holes than you're shower head. Talk to a radiator shop, they'll prefer to sell you a new one at gitgo.