D-I-Y Cooling System Flushing

[anthonemorris]

Basics needed:

• radiator flush
• coolant
• hose and running water
• gloves (optional but recommended)
• common sense (most important)
• if necessary, tools to remove expansion bottle (most cars they just slide off their mount)

WARNING: if being done on a hot engine note that water or coolant will be at or above boiling point and burns can occur

So here is what i used for my car:

two bottles of flush
coolant
coolant additive

why did i use two flushes? this is why

my radiator and cap were coated in rust and broken down coolant

so to start i drained the radiator a bit to accommodate the addition of the system flush.
then i removed the expansion bottle and emptied it of its rust brown liquid and sprayed a degreaser to help clean it.
after i did that as per the recommendation of the flush bottle i let my car run at high idle (2500rpm at least) for 15min for it to take effect.
i drained the system and ran it again as per recommendation on bottle *each flush has its own instructions, follow them*

i then drained again and flushed again with water and then drained another time (yup 3 or 4 drainings of the system)

so now i was ready for the filling and added the coolant additive first so that when i added the coolant it would mix properly and i filled the radiator to its full mark
i then proceeded to re-attach my cleaned expansion bottle and fill it with coolant 1/2 way.

with the radiator cap off i started my car to let some of the air pockets run through the system to escape through the open cap. i then closed off the system and filled my expansion bottle to its full mark

so far no problems.

 

[BrotherHood]

Excellent job man. Nice write up. You making me want to do same this coming weekend.

 

[nirtime]

Great writeup, makes it really easy to understand the procedure. Reminds me to go check mine now.

 

[anthonemorris]

Just a note to be careful with the coolant that you are using. If it's a premixed 50/50 then just pour and go. If it's a concentrate then I would advise a 70/30 mix concentrate/water as that ratio gives the best cooling properties. Try to mix it beforehand if possible. Also always follow or try to follow the instructions on the bottles. Could mean the difference between a good working engine or a blown head.

 

[Steven Ramadar]

Look at that, I always thought you pour the coolant straight in. Good thread!

 

[anthonemorris]

As far as how often a flush should be done I took a read of this article and twice a year should be done for our climate.

https://automechanics.wordpress.com/2008/06/20/car-maintenance-101-flushing-your-vehicle%E2%80%99s-cooling-system/

 

[anthonemorris]

How to Quick Flush Your Cars Cooling System


[video=youtube;g8YZF5cW7-A]https://www.youtube.com/watch?v=g8YZF5cW7-A[/video]

 

[anthonemorris]

Ok so just a quick note that i picked up while doing this on my civic (which i no longer have), flushing a high mileage engine may lead to unexpected expenses. As much as we get rust and other debris out of the system for it to be more efficient in cooling we also be pulling the debris that holds it all together in a sense. On the civic i flushed my system twice as it was very badly off and started to use coolant after the second flush. this was where things got out of hand.

While using water the car never overheated or the temp gauge move more than where it should be but i was losing water still. So i flushed and used water again and did a compression test. Compression was great. Still had water disappear. So i did the second flush and used coolant to fill up. Was working well until the car started to constantly overheat and the culprit was the radiator (or so i thought) as i was seeing coolant running out the front of it. So i went to investigate further and found a pinhole leak behind the water pump by the bypass pipe, but it only sprayed at high rpm (3700+) so i just started driving like a granny and the car stopped overheating for a while but it started again. So both leaks had gotten worse by that time.

So i had to hit the mechanic. All hoses, thermostat cover, thermostat housing, thermostat, bypass pipe, seals, and radiator were shot. Everything was rusted away and it was all due to cleaning out the rust from the system. Cost me $3500 in total to service the car.

So just a reminder to the D-I-Y crowd, use caution in what you do. i did nothing wrong here, but the internal conditions you can never know.

I recommend a pressure test every time you are about to change/flush your cooling system or if you have any irregularities. could save you some $$$.