6G Celicas Forums

how do you properly flush the cooling system of a car?

I know the basics like hook up a garden hose and run water through the system as the engine is runing and heater on to help remove all the rust and containaments in there.

But what do you do with all that radiator fluid? You can't just let that drain into the storm drains.


And your not suppose to get hard water into the cooling system, that is why distilled water is needed. And flushing the cooling with gallons and gallons of distilled water will be very costly....

What about those chemicals you can buy?

What is the best way to do it? To be honest i dont trust those jiffy lube shops to flush my car, they probably wont use distilled water...

yeah but jiffy lube won't use a garden hose

go to the dealer, it'll cost you like $160, which is probably about the same as anywhere else. They hook up the car to a machine that pumps it all out and pumps the new fluid in. I don't think I would even try the garden hose idea.

dealer wont use distilled either lol, they'll just pull your heater hoses, hookup the garden hose, and shove the water through the heater core backwards and forwards, then do the same to the block and radiator.


the key is to then blow compressed air through gently to remove the hard water.

Not for nothin, but sometimes you do what you gotta do. I ran a hose on my '87 Pathfinder, and it worked just fine. I don't know if my water is hard or not, that will vary from locale to locale. If you're really concerned about hard water deposits, you can buy a water softener, I believe it's actually a salt type of stuff... but it doesn't make the water salty. My mom lives in Vegas where the water is so hard you need a chisel for it... she's got a special tank that takes the salt stuff (maybe it's just in her hot water heater, I don't remember) and the water is used throughout the house. No salty showers or tooth brushing though.

i flushed my system using a garden hose through the heater lines, and radiator. then i used Gunk coolant flush for 20 mins and flushed it out again with the hose. then i used toyota prediluted pink coolant to fill the cooling system.
after all that, my heater works much much better than before, i'm actually looking forward to -40 degree weather to compare how it was like before.

how do you exactly connect to the heater hoses

they sell a kit with a 3/4" garden thread connector that has two barb t's.

all i do is drain freeze,ran water through system,then put coolant in and run the engine for a while and add more and thats it!!!

I actually work at jiffy lube, and we do the same as any dealership when it comes to flushing a coolant system. Our store is a stand up shop and we do everything by the book, i cant say the same for others stores tho.

i have a narrow garden hose nozzle and i basically cupped my hand around the end of the nozzle joining the heater line hose.
whatever works..

the main reason i ask this question is because people spend money on distilled water to hope that there will not be any funk chemical that will cause the engine to rust, corroide or oxidize. And using toyota red coolent is proven to help keep metals from oxidizing and what not, But that only holds true if there is nothing else in the coolant. If your water is treated like most cities, there will be clorine, calcium, salt and other junk that will be in the water. So why bother spending extra money on toyota coolant when you can not get a complete clean cooling system?

No matter how you flush your system you will have unknown chemicals in there.

I personally flush many cooling systems my self and know the steps on how to do it. But I can't seem to find a "clean" way to do it.





Does your shop use tap water ( or water from the cities water lines) to flush the coolant systems?

we just use the water from the city, as i'm sure most other places will do as well.

What do you do with the waste water?

you're all acting like the cooling system needs to be perfect and sterile and the tiniest bit of minerals or chlorine is going to to totally destroy the engine, no matter what theres ALWAYS a little of something in there. right from the factory theres a little oil in your cooling system, some dust, some dirt, etc.

Previously had a '94 GT that developed a radiator leak. Replaced it 6 or 7 times with a "1800radiator.com" replacement. Stuck with them 'cause of the lifetime warranty. Lost that one in a crash and now have a '98 GT that I'm more cautious with. Last year did the timing belt & pulleys and the water pump while I was at it. Started with draining coolant from the radiator; could not loosen the engine drain plug so I had to go through multiple fill & drain sequences using tap water from a "Pur" water filter. Used filtered water 'cause I have pretty hard water in So Cal.

Have plenty of containers available to collect the drained stuff. In LA county we can take this to a haz mat round-up. Ask your parts store about what to do with the waste. Pay attention to how much drains out and compare it to the stated capacity; I was able to get a little more than 50 % out at one time. Drained and filled a couple times and then used 2 bottles (I think 20 oz. per bottle) of Prestone's flush (citric acid) and ran the engine to normal operating temp with the heater fully opened. Then did multiple fill-heat-drain to get the concentration down to 1 to 2% The math isn't too hard: 50, 25, 12.5, 7, 3.5, 2, 1%; so 6 or 7 fill-heat-drain sequences were enough. Once down to the smaller %'s, the drained liquid went into the toilet.

Did this a year ago and the temp gauge still doesn't budge above the usual spot; and it's about 100° this weekend in So Cal.

found this so i decided to give proper credit.


My first drain was about 1 gallon, donk know if its ok, maybe some of it is still in the blok, so i refilled it with prestone 50 50 and ran it for 30 seconds.

am about to drain it again. i guess putting coolant instead of water is beter. I will redrain and install my rad. When i do the swap i will do better flush.

hahaha im stuck on step 1

does the 7afe have a block drain plug on it somewhere?

I bought a 10L container of distilled water for my 1st Celica car and my mechanic told me it was a waste and I might aswell drink it.. Then I realised, This is stupid, I treat my cars better than my own body.

your body can heal itself, your car can not.