Best way to flush / clean radiator. Not installed.

[rcl700]

I'm looking for information on the best way to cleanout the radiator from 48' plymouth. I have the motor pulled and radiator. I'm wondering if I can use distilled vinegar to soak in the the radiator, or if there is another product I should be looking at. Also what the best process. I was thinking of plugging the lower hose and filling with cleaner for a few days then flushing with a hose. I know there are radiator flush products but I think they are designed for use on installed radiator with engine heat applied. 

 

 

Edited March 18 by rcl700

[Ivan_B]

When the radiator is out of the car, you can do anything you want, even take the core apart

Plug the overflow, put it on the front side, poor vinegar inside, leave for a few hours, drain (do not discard yet) check the results. If not good enough - repeat.

If you want to use commercial products, like the coffee maker/cattle cleaner, you can boil it with some water and poor inside your radiator.

When the acid treatment is done, flush it with the garden hose, both ways. Once that is done, flush with distilled water, and dry.

Edited March 18 by Ivan_B

[rcl700]

Good deal. Thanks Sir. 

[Sniper]

There might be a radiator shop near you than can clean and test it.

[Doug&Deb]

Just be careful with the radiator shop. Your car has a non pressurized system and if they pressure test it bad things happen.

[Ivan_B]

That's a good point. For starters, filling it with boiling water and checking for leaks should probably be sufficient.

The non-pressurized system is great, by the way! No need to gorilla-clamp the hose connectors, etc.

[Dan Hiebert]

Start simple.  Flush it in both directions with clean water.  Pay attention to the flow in each direction, as well as how much stuff is in the water.  If it doesn't flow to your satisfaction, or if you don't like how much gunk is in the water, then apply more caustic remedies. 

 

Check for leaks by submerging the radiator after it's drained and using air.  Plug the filler neck, inlet, and outlet, apply air to the overflow at very low psi, as in no more than 5 psi or so.  Any leaks will be more apparent this way.