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how do you flush a radiator?? Answered

i cant find a instructable for this one, how do you flush your radiator???


Cut it up into little pieces with a Stihl-type power-saw.
Put the bits in freezer-bags, and the metal-filings you sweep-up.
Bag them like goldfish so there's enough air in there, to give them a density of not much less than water. You want them to "not-quite float".
Flush one bag at a time, and check for signs of clogging.


Check ou "Esmagamus guide: living with your car's cooling system".

I have an example procedure there, it's not hard to do.


10 years ago

I've used inexpensive "flush kits" in the past.

They usually include a "T" connector that you splice into a coolant hose--that's where you attach your garden hose. Where you splice the water input matters, since the thermostat will be closed when the engine is cool. The directions should guide you to the correct spot.

Most include a little spout--you remove the radiator cap and insert it. It just shoots the water away from the car and the radiator.

Then you open the drain petcock, turn on the water and let it run for a few minutes. Beats me if it flushes as throughly as a professional flush, though.

i disconnected one of the hoses today from the radiator, took off the coolant tank (where you fill it up with coolant) and cleaned both, disgusting as both were FILLED with rust... i power sprayed it with a garden hose that has the spray gun on it for a while....alot of brown...stuff....came out... =/ then i put the garden hose in the radiator from the top and power sprayed that too after covering the engine with a thick labor moving blanket. alot of crap came from there too, but isprayed till it was just water...i couldnt find the drain petcock so i have to deal with running the car on water for a little bit, and i already bought the antifreeze mixed with water. i just wish i can find that petcock to drain all the crap out
any help...?

. "Running the car on water" is probably what caused all the rust in the first place. Get some antifreeze (most AFs have rust/corrosion inhibitors) in there ASAP. . You really need to find the petcock on the bottom of the radiator. The petcock may be located at a low point somewhere else on the system. If you can't find a petcock, remove the lower radiator hose (while the engine is cold). . Be prepared to replace your water pump. The rust and gunk you've stirred up may get into the seal. :(

Yes, follow NachoM's lead, and look to the bottom of the radiator. In my experience, they are usually side-mounted. I've linked an image of a petcock valve, but this one is mounted on the bottom. The valve is in the very center... It's possible (but unlikely) that your radiator doesn't have one.


Depending on the make and model of your car, there should be a small petcock near the bottom of your radiator, if there is not, you remove the lower radiator hose. Remove cap place large container under petcock or hose open petcock or remove hose. drain. remove container (take to recycler) replace hose or tighten petcock add coolant.

but dont you need to "flush" the radiator, incase theres debrii in there of some sort? i have a 1993 pontiac bonneville ssei (supercharged)

Yeah, knew I left something off. ;-) I just park it on the grass, and run the hose in the top and fill and drain a couple of times.


10 years ago

How do you flush a radiator?

Well, you would need a [rhttp://www.the-rocketman.com/art-center.html really powerful toilet], obviously...


. I'd follow most of what TUA said, but I'd fill the system with clean water, run 'til warm, and drain, before adding antifreeze/coolant. You can get chemical flushes at most auto parts stores and larger department stores, but I don't recommend these, especially on modern aluminum engines.
. Make sure the engine and radiator are at ambient temp (at least below, say, 150oF) before removing the cap or opening the petcock.