coolant flush
LS1Tech Sponsor
Joined: Jan 2008
Posts: 2,233
Likes: 1,522
From: Ohio, Georgia, Nevada, Texas
A coolant flush is a pretty straight forward maintenance job that can be done with a basic fitting and a garden hose. We offer some Dorman Radiator Flush T fittings to run inline with your heater hoses making the job easier. You will run the water pressure opposite of normal flow since this will push blockages out of the heater core. You may want to consider refilling with a quality coolant like Be Cool Antifreeze due to its extended life, leak sealing additives and it's earth friendly.
Here's my write-up:
Best/easiest way to flush and get every drop of old coolant out.
****My power steering fluid leaked into my block, so it was bad, but this flush process works for normal maintenance flushes too. You might just want to skip the degreaser stages.****
-Cold engine.
-Remove radiator fill cap.
-Remove the t-stat from the housing. ((Buy a new t-stat housing gasket, they're like $3.00)) Leave the housing attached to the rubber radiator hose, just remove the 2 housing bolts and pull it away from the water pump to get to the t-stat. (2-3 minute job). ***The t-stat itself can be removed from the so-called one piece t-stats just like we can remove the t-stat from the newer two-piece t-stats. And the housings will bolt right back to the water pump.***
-Put t-stat housing back on. (1 minute) Just put one bolt in, no need to put them both in, there’s no pressure in the system during the flush.
-Take the entire radiator drain valve (petcock) "off" and let it drain, don't just open the valve itself. It'll drain faster with it off and that’s what you want. ((Buy a new petcock valve before starting this flush process, sometimes they break when you remove them all the way just because they're cheap plastic and they get briddle over time, they're like $2.00))
-Take a hose and stick it in the radiator fill cap, running medium to high.
-Start the engine when the radiator looks like its full again.
-Turn heat on full blast
-Let it run for about 15-20 minutes or until the water is running out the drain CLEAR.
-((If you want to, you can wait till it runs clear, "close" the drain valve, add some degreaser (I use ½ gallon of Formula 88 to clean mine) and let it run for 15 minutes, then let it sit for 15 minutes, then run it for 5 minutes, then drain it all again. Then open the drain and put the hose in for about 5 more minutes and run it all out till its CLEAR. The degreaser will help break up the crap thats stuck DEEP in the BLOCK that sits and swirls and doesn't like to come out.)) NOTE---Some degreasers like Formula 88 will make a lot of "foam" when rinsing it out of the radiator/engine, it may take a little linger to clear it all out of there. Just rinse till water runs clear with no foam present. ***NO…degreaser will not hurt anything. Just make sure its ok for aluminum.***
-When it runs clear your entire system is clean.
-Remove the overflow reservoir from the car and clean it out real good. (I had to use gasoline to clean mine out because the sludge and grime was so thick inside. The gas broke it all down and then it flushed right out. I filled it about 1/3 up with gasoline and shook the hell out of it real vigorously, the black stuff kept coming out. I did that like 4 separate times with gasoline till no more chunks of black crap came out. Make sure the lines that go to the reservoir are also cleaned out. Or just buy a new piece of 3/8” heater hose and replace that line, 3 feet will do, then cut to fit. My sludge came from my power steering fluid leaking into my coolant system.)
-Put the t-stat back in.
-Put the overflow reservoir back in.
-Put the drain valve back in. Use the new one, what the hell.
-Put half a jug of Dexcool in the radiator. (Or if you live in very cold places, 1 to 1 ½ jugs of Dexcool)
-Fill the rest with water.
***You do not need to use distilled water, clean hose water is just fine, just make sure your city water is clean and not total crap quality.
**Bleeding the system of air:
Take the radiator cap off when its COLD, top it off, start it up and let it idle, and let it warm up till the t-stat opens. I rapidly squeeze the upper and lower radiator hose like 20 times each while its warming up to help move any air bubbles through the system and by the t-stat on the engine side. When the t-stat opens you’ll see the level drop as you squeeze the hoses, its sucking the coolant through the system. You will also see the coolant start to flow in the radiator fill neck, once it starts to flow the level should drop down a lot, IMMEDIATELY top it off with coolant/water. Then the flow will stop when the t-stat closes. Wait one more time for the t-stat to open again and start to flow, if it drops down again top it off again. Do it a 3rd time if you want to make sure. When the level does NOT drop down when the t-stat opens and coolant is flowing....you're system is free of air bubbles. I always squeeze the upper hose during the whole process to keep any air bubbles moving through. Always works like a charm. Just keep checking your temp gauge until the t-stat opens for the first time to make sure it’s not sitting there overheating from a trapped bubble. May take 10-15 minutes for the t-stat to open the first time.
If you do start to get hot while sitting there and the t-stat will not open…..you have a good sized air bubble on the engine side of the t-stat. Shut the engine off and rapidly squeeze the upper and lower radiator hoses again. Then start the engine again and see if the t-stat will open. Sometimes you just have to work those hoses to move the air through. Even after it seems topped off after a couple cycles…check it the next time you have a cold engine…top off if needed.
.
Best/easiest way to flush and get every drop of old coolant out.
****My power steering fluid leaked into my block, so it was bad, but this flush process works for normal maintenance flushes too. You might just want to skip the degreaser stages.****
-Cold engine.
-Remove radiator fill cap.
-Remove the t-stat from the housing. ((Buy a new t-stat housing gasket, they're like $3.00)) Leave the housing attached to the rubber radiator hose, just remove the 2 housing bolts and pull it away from the water pump to get to the t-stat. (2-3 minute job). ***The t-stat itself can be removed from the so-called one piece t-stats just like we can remove the t-stat from the newer two-piece t-stats. And the housings will bolt right back to the water pump.***
-Put t-stat housing back on. (1 minute) Just put one bolt in, no need to put them both in, there’s no pressure in the system during the flush.
-Take the entire radiator drain valve (petcock) "off" and let it drain, don't just open the valve itself. It'll drain faster with it off and that’s what you want. ((Buy a new petcock valve before starting this flush process, sometimes they break when you remove them all the way just because they're cheap plastic and they get briddle over time, they're like $2.00))
-Take a hose and stick it in the radiator fill cap, running medium to high.
-Start the engine when the radiator looks like its full again.
-Turn heat on full blast
-Let it run for about 15-20 minutes or until the water is running out the drain CLEAR.
-((If you want to, you can wait till it runs clear, "close" the drain valve, add some degreaser (I use ½ gallon of Formula 88 to clean mine) and let it run for 15 minutes, then let it sit for 15 minutes, then run it for 5 minutes, then drain it all again. Then open the drain and put the hose in for about 5 more minutes and run it all out till its CLEAR. The degreaser will help break up the crap thats stuck DEEP in the BLOCK that sits and swirls and doesn't like to come out.)) NOTE---Some degreasers like Formula 88 will make a lot of "foam" when rinsing it out of the radiator/engine, it may take a little linger to clear it all out of there. Just rinse till water runs clear with no foam present. ***NO…degreaser will not hurt anything. Just make sure its ok for aluminum.***
-When it runs clear your entire system is clean.
-Remove the overflow reservoir from the car and clean it out real good. (I had to use gasoline to clean mine out because the sludge and grime was so thick inside. The gas broke it all down and then it flushed right out. I filled it about 1/3 up with gasoline and shook the hell out of it real vigorously, the black stuff kept coming out. I did that like 4 separate times with gasoline till no more chunks of black crap came out. Make sure the lines that go to the reservoir are also cleaned out. Or just buy a new piece of 3/8” heater hose and replace that line, 3 feet will do, then cut to fit. My sludge came from my power steering fluid leaking into my coolant system.)
-Put the t-stat back in.
-Put the overflow reservoir back in.
-Put the drain valve back in. Use the new one, what the hell.
-Put half a jug of Dexcool in the radiator. (Or if you live in very cold places, 1 to 1 ½ jugs of Dexcool)
-Fill the rest with water.
***You do not need to use distilled water, clean hose water is just fine, just make sure your city water is clean and not total crap quality.
**Bleeding the system of air:
Take the radiator cap off when its COLD, top it off, start it up and let it idle, and let it warm up till the t-stat opens. I rapidly squeeze the upper and lower radiator hose like 20 times each while its warming up to help move any air bubbles through the system and by the t-stat on the engine side. When the t-stat opens you’ll see the level drop as you squeeze the hoses, its sucking the coolant through the system. You will also see the coolant start to flow in the radiator fill neck, once it starts to flow the level should drop down a lot, IMMEDIATELY top it off with coolant/water. Then the flow will stop when the t-stat closes. Wait one more time for the t-stat to open again and start to flow, if it drops down again top it off again. Do it a 3rd time if you want to make sure. When the level does NOT drop down when the t-stat opens and coolant is flowing....you're system is free of air bubbles. I always squeeze the upper hose during the whole process to keep any air bubbles moving through. Always works like a charm. Just keep checking your temp gauge until the t-stat opens for the first time to make sure it’s not sitting there overheating from a trapped bubble. May take 10-15 minutes for the t-stat to open the first time.
If you do start to get hot while sitting there and the t-stat will not open…..you have a good sized air bubble on the engine side of the t-stat. Shut the engine off and rapidly squeeze the upper and lower radiator hoses again. Then start the engine again and see if the t-stat will open. Sometimes you just have to work those hoses to move the air through. Even after it seems topped off after a couple cycles…check it the next time you have a cold engine…top off if needed.
.
LS1Tech Sponsor
Joined: Jan 2008
Posts: 2,233
Likes: 1,522
From: Ohio, Georgia, Nevada, Texas
