I changed the coolant in my car and not wishing to go through a lengthy and messy flush I decided to drain the antifreeze and flush twice with distilled water.

What I wanted to do was have the least possible amount of coolant to take to the hazardous waste disposal site. I did not want any to be flushed into the sewers by draining it on the driveway, this is illegal around here.

Using the quantity of coolant removed each time I calculated the amount of original coolant left in the system and used this to determine the amount that required to be added to reach the 50/50 mix specified. I marked buckets with graduations in liters.

Two gallons of Zerex G-05 concentrate, 6" of 3/8" ID hose and a wide screwdriver for the draincock. You cannot say drain **** as separate words. Is this discrimination against male birds?

Your challenge is to mathematically calculate the amount of coolant to be added at the end of the process and I will check my own figure. Easy eh?

The SRT6 is said to have a coolant capacity of 14.5 liters.

1, I managed to get 9.5 liters out the first time.

2, I filled with 8 liters of distilled water and ran her up to temperature, with hot water going to the IC and heater systems. Then I managed to drain 8 liters.

3, I filled again with 8 liters, repeated the heating cycle and re drained 8 liters.

4, I filled with my calculated antifreeze amount and topped it up with distilled water. I then took it for a long drive,left it to cool down and topped it up again with about a liter or so of water. I think I will have to top it up again with about another 1/2 liter after another drive. It seems to take a while to balance out and that amount will bring me up to the amount I removed the first time. The coolant in the tank is now clear green, the blue dye in the OEM coolant tinting the very light yellow of the Zerex. You can now easily see the bottom of the tank through the coolant.

Your task if you decide to take the challenge is to calculate how much new antifreeze is to be added to make a 50/50 mix in the system. Your computer will not self destruct after you have read this as in Mission Impossible.

I was surprised at how much was trapped in the system, I wonder how much would have come out if I could have found a block drain.

The simple method would have been to drain, flush and then add 7.25 liters, but as I always say how hard can it be to do it exactly. LOL

Removing and replacing the belly pan was a major pain with the car on the ground and the two clips seem useless unless they are broken, they fit in the slots but fall out again. Are mine broken or bent or am I missing something?

 

Dave,

FWIW, I recently replaced the radiator in my sons' 1997 Lincoln Town Car (4.6 l V8) and it took quite a number of hours of running to burp out all of the air. 3 liters of air! And I disconnected the upper rad hose and filled the rad before sealing it up.

I recently learned of some air-powered vacuum cooling system service tool


that's supposed to make this issue a thing of the past.

 

I agree it's not as easy as it was back in the day, drain it on the driveway, stick a hose in the rad, run it to flush it out, use corrosive substances to clean every thing inside, then pour in the coolant and add water, then top up the next day if needed. Do that every other year.

Animals, fish and insects died every time someone changed their anti-freeze. The good old days. No wonder we are in a mess. LOL

They use something like the apparatus you describe at the assembly plants, stick a hose on and bingo all filled to spec. Nobody wants to go out and waste time checking the level a couple of times. The filler wore a rubber apron and boots, maybe its a bit cleaner these days.

 

Mine were both broken also when I bought the car.
I made the following mod :

Hold the belly pan up as far as it will go on the clips and drill a small hole in the clip at that point.
Put a cotter key through the hole to hold the pan up. No need to bend the cotter key, mine have stayed in place just fine for almost 2 years now .....

 

Thanks for the tip.. Due to change oil this week and will do this one myself while I'm there. Same "fits but wont stay" issue.

 

Dave, answering your quiz accurately is impossible. Each time you added water and flushed, a different ratio of coolant was drained out. Why? Because of the coolant that was left in your IC system/circuit and mixing with the added water at an unknown factor/ratio because of the shared OEM surge tank. To get all the coolant out of the IC system, you need to open up the lower hoses to the Heat Exchanger and or remove the Heat Exchanger from its perch and dangle it down and open its draincock. And then, to really get it all out, compressed air(10p.s.i. or so). This procedure is not in the service manual. All it shows is the HE dangling, to drain for removal. Yes, a huge PITA. Fortunately it doesn't have to happen very often. Did I mention that you need to remove the front bumper to do all that? When I split my systems up, and added a Bigger HE and small fill tank, I plumbed in a tee in the lower hose and added a new draincock, so the next time I want to flush the IC circuit, I can open the new drain below. Those that are using the Supercooler have a draincock.

 

I suggest you use the hygrometer to test the concentration and determine the exact freezing point. Saves a lot of calculation and is still accurate. Taaa Daaaa Woody

 

I actually used low pressure compressed air on the whole system and the IC system directly. The first flush fluid was really dark still and the second was clear enough to easily see the bottom of the bucket about 12" deep fluid. All lines heated up and the fan came on, I estimate an air lock of 1.5 liters, 9.5 - 8 liters. On the first drain I emptied the hose above the thermostat and the lower hose, I think this netted about 1/2 liter. In my first post I said I think it will need a further liter or so, that is wrong I think it will be less than a 1/2 liter.

I think a good estimate can be made, there remained 5 liters after the first drain of which 2.5 liters was antifreeze, subsequent flushes reduced this concentration. How much remained after the second flush?

Where are the mathematicians on this forum?

 

Sounds like a lot of rock and roll Dave! My gizintas and cyferin ain't too good so when it comes my turn to do this, I'll take the easy route and have Rudy put a V8 in.......

 

One would presume that after the first drain/refill that there would remain 2.5 liters of coolant in with the 8 liters of distilled water you filled it with, plus 2.5 liters of water already in from original fill (IF the original fill was still 50/50) . This would make it ~ a 19% mix of coolant (10.5 water, 2.5 coolant). Provided the mixture blended completely with the water, when you drained and added 8 liters of straight water, you drained out a touch under 6.5 liters of water and a touch over 1.5 liters of the original coolant. This leaves ~1 liter of original coolant still in the system. Refilling again brings the ratio down to .03%. So your remaining 5 liters is only .39 liters of coolant, the rest straight water. Topped off at 50/50 gives you 8.6 liters of water to only 4.39 liters of coolant (34% mixture).

 

So simple, a caveman could almost do it.

 

My math (good luck following it! It confuses even me!);

Start out with 50/50 mix
__________________________________________7.25L water 7.25L coolant
Remove 9 liters of mix_______________________ -4.25L water -4.25L coolant
Add 8 liters water___________________________10.5L water 2.5L coolant 19% mix (2.5L devided by 13L total amount of fluid)
Remove 8 liters of mix (61% of total fluids)_______ -6.5L water -1.5L coolant (10.5L water *.61 = 6.5, 2.5L coolant *.61=1.5)
Add 8 liters water___________________________ 12.0L water 1.0L coolant 7% mix (1L devided by 13L total amount of fluid)
Remove 8 liters of mix (61% of total fliuds)_______ -7.4L water -.6L coolant (12L water *.61=7.4, 1L coolant *.61=.6L)
Add 4L of water and 4 of coolant________________ 8.6L water 4.4L coolant 34% mix (4.4L devided by 13L total amount of fluid)

Even if you get it completely topped off (at full 14.5L) with 50/50 mix from a bottle you are only adding another .75L of coolant. This gives you a slightly better 35% mixture.

 

To make it easy and discard all irrelevant numbers just work with what is left in the system not what is taken out.

After first drain there is 2.5 liters water and 2.5 liters of coolant in the system, a 50/50 mix.

In the system after adding 8 liters is, (8 + 2.5 ) liters of water and 2.5 liters of coolant.

Remove 8 liters which is 61.5% (8/13 x 100) and there remains 38.5% in the system. 38.5 % of 2.5
= .96 liter

After adding 8 liters there is (8 + 4.04)liters of water and .96 liters of coolant in the system.

Remove 8 liters = 61.5% and there remains 38.5% of the .96 liters = .37 liters coolant and 4.63 liters of water in the system.

The full system requires 7,25 liters water and 7.25 liters of coolant, so add 6.88 liters of coolant and top up with 2.62 liters of water.

(6.88 new + .37 old) coolant + (2.62 new + 4.63 old) water = 14.5 liters

I think this is correct, I get the same figure if I do it in fractions rather than percentage.

MoparFreak69 is correct. Cool is appropriate here I think.

I went to a 50/50 mix in the system.

 

I didnt go quite as precise, but its all good. Results are pretty much the same.

 

Did you turn the heat on 'high' and run the fan at least on high enough to fully open the heater core valves? Doing so may increase the reduction of the concentration, and help keep the air bubbles to a lower amount (the water pump actually pushes air through some when it is running. How does the heater work now? Anyway, whenever I flush/fill systems I turn the heat to high/high and let the W/P help me replace more coolant during flush/fill.


Ooops, NM, I see step 2 I misread that one! Sowery!

 

Great thread! I noticed in the service manual they refer to "reverse flushing" with compressed air and water. I believe the majority of shops have some sort of machine that flushes the old coolant out. But that method will still not remove any of the fluid from the heat ex changer setup correct since it is separate? Only area where it ties together is the coolant overflow tank correct? So the DIY method seems to be the best route.

So in a nutshell:
Drain original fluid
Fill tank to max with distilled water
Drive car with heater on full blast. Get it up to temp and then do a couple WOT pulls.
Let car sit for a while
Drain fluid out
Fill with water again and repeat driving and cool down procedure.
Drain fluid out
Fill with 50/50 G05/distilled water mix to max level on overflow tank

Correct?

 

I disconnected the IC hoses and blew down them with low pressure air. I also blew into the main system with low pressure air and it actually got quite a bit extra out.
When filling I added the correct amount of G05 and topped up with distilled water. I figured it would soon mix up inside the engine.

 

OK so basicly doing it this way do I leave the NW Coolant Separation Kit OPEN or CLOSED while doing all this ??

So in a nutshell:
Drain original fluid
Fill tank to max with distilled water
Drive car with heater on full blast. Get it up to temp and then do a couple WOT pulls.
Let car sit for a while
Drain fluid out
Fill with water again and repeat driving and cool down procedure.
Drain fluid out
Fill with 50/50 G05/distilled water mix to max level on overflow tank