Thinking of doing coolant flush

[Pruitoverdrive]

Hello
New here, owned a manual 07 Gt for a little over a year now. First car that I've owned where I can do "work" on it. Studying for an engineering degree currently and I'd say I know my way around most mechanical things in a car. Have been interested and educating myself on vehicles for years now and finally I have the opportunity to work with them.

I've been looking at all the videos and forum posts about doing a radiator flush which I know I have to do soon. I'd say I'm 60-75% confident in being able to do something like this. The other reason I want to do it myself is to save the money rather than taking it to a shop- I am a broke college student and had a minor $2k accident already this summer.

Here's the process I would take:
1. Jack up car
2. Open coolant reservoir on top.
3. Drain all liquid from Petcock valve at the bottom of radiator*
4. Fill with Prestone Total Fluid System Cleaner and appropriate amount of distilled water.
5 With heat all the way up run car for 1-2 hours.
6 Drain from petcok
7 Fill with distilled water, run, drain. A few times
8 Fill with appropriate coolant/water ratio
9 Run, drain, and if I can get my hands on a coolant tester, test liquid and keep adding appropriate liquid.
10 Pinch various radiator hoses and try to get all air out**

Any guidance or perspectives on this project would be much appreciated. Thank you for your time.


Feel absolutely free to correct me if I'm wrong about something

* If Im correct this won't drain nearly all the fluid because most of it is in the block.
** This is the part that's keeping me up at night

 

[Samos3]

Air shouldn't be much of a problem. Just pour the coolant and water in slow. Let it burp. Repeat. Run with cap off and watch as more bubbles come out until coolant level starts to rise. Put cap on and run for a bit more. Then let it cool down overnight. Check level the next morning. Might take a couple repeats until it stabilizes.

The problem I had when I did it is that draining from the petcock will get about 6-7 quarts out at a time. Not a very efficient flushing method! I think there is, what...23 quarts or something in the cooling system? You need to get all the system cleaner out as it is an acid. So figure out how many drains/fills at 6-7 quarts at a time until the dilution gets near zero. Refilling that way can get costly as you are draining out some of the fresh new coolant everytime you drain. I used the Zerex Gold from Autozone at half the price of Motorcraft Gold.

Generates a bunch of contaminated water/coolant, too, so depending on your level of environmental concern, that might be an issue.

A dealer flush might actually be cheaper/less headache and downtime.

What is the mileage on the car? Do you know if/when the coolant/heater hoses were changed? Given the hassle on the coolant flush once you have the system open, it is worth considering doing the hoses, especially the heater hoses and the nipple and it's rubber seals in the back of the water pump under the intake manifold (manifold comes off to do this). I used Genuine Motorcraft parts where I could as they had lasted 200k miles, mine were original. Some people just use generic heater hose and hose clamps under there, but it's a bad spot to have to address a leak later on.

Oh, yeah, and the thermostat, gaskets and crossover gaskets. And the water pump. The list grows...but like I said, once you drain the system, parts cost aside, why not?

 

[Dino Dino Bambino]

@Pruitoverdrive the only thing I'd add to your procedure is to disconnect the lower radiator hose from the radiator. This will allow more old coolant to drain from the engine.
If any coolant hoses are hard and crusty, replace them. The chances are that if one of them is like that, they'll all be especially if they're the original factory items. As @Samos3 suggested, don't forget the heater hoses that run under the intake manifold. A future leak from there would be a real PITA.

 

[Samos3]

Oh, yeah, also....any hose connection that is made of the black plastic will probably be at the end of it's life cycle. They get brittle over time and crack. I've even had them crumble like a dry cookie.

 

[07 Boss]

You will never get everything out of the system but the more times you "rinse" it after the flush and before your final fill. Don't worry about it. If you are you can run it a couple of times with just water and any junk left behind will be minimal. Also no need for actual coolant when you rinse it, just use water. In fact, depending on where you live you may not need that much coolant. I run straight distilled water and a bottle of water wetter, no antifreeze.

 

[Samos3]

You will never get everything out of the system but the more times you "rinse" it after the flush and before your final fill. Don't worry about it. If you are you can run it a couple of times with just water and any junk left behind will be minimal. Also no need for actual coolant when you rinse it, just use water. In fact, depending on where you live you may not need that much coolant. I run straight distilled water and a bottle of water wetter, no antifreeze.

I reread my post and I didn't make it clear that rinsing after the system cleaner is done with straight water. Get the dilution down as far as you can, THEN starting replacing that with coolant.
That's what I get for posting at bedtime...

 

[Autokyrios]

Like others have said, if you really want to do this short n sweet and don't mind taking it into Ford, having them do a flush with their equipment is way easier and is usually really cheap, especially if you get it with an oil change and such.
Just make sure if you pour regular water in it that you flush all that out. You only want distilled water in there (if you run any water at all). If there's any minerals/etc in it, you'll get corrosion.

If you follow the procedure in the manual, you'll be fine. Fill it up, run the engine with the heater on MAX for a little bit, then let it rest. You should see some fluid go down in the reservoir. Top it off, then go for a drive. You've got plenty of fluid in the tank so unless you have a leak you won't run too low. If the car actually overheats and there's no leaks...yeah I'd have to wonder what you did.

I have a vacuum coolant fill tool that's supposed to evacuate all the air, but I still go through the same motions anyway. Never had the need but it's just comfort I guess.