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2001 Windstar coolant flush, rear acc heat??

09-27-2006, 11:17 PM
Hey all,

I just bought a 2001 SE Sport and am going through the list of 'things to do' that I've found here, in Haynes and in the Ford service manual and maintenance schedules.

I'm about to flush the coolant and replace it but I'm having a bit of trouble before I get started. I have the procedure to flush engine/rad, and backflush heater core, but how does the rear accessory heat figure into this? I'm not even sure how it operates and I'm having trouble finding info on it.

About the only thing I can find is in Haynes which says the standard heater holds 15 quarts and the rear aux heater holds 16 quarts of coolant!!! I hope they mean it holds 1 more quart than the 15 in the rad!!

Anyway, before I get started on this can anyone give me some insight into the rear aux heater? Also, any tips you have about cleaing it out would be appreciated.

One more thing. Ford recommends clean tap water. Anyone use distilled instead?

09-28-2006, 03:22 AM
You're correct, the rear heater adds 1 qt to the whole system.

There are no water valves in the heater system. The two heater-coils are hooked up in "parallel". All of the temp control is achieved by air blend doors ... mixing hot and cold air streams.

I think tap water is fine for the flushing procedure. Pushing out the flushing water with a final compressed air blow out is good. Distilled water is a good choice for the fill-up.

09-28-2006, 06:56 AM
Personally, I used distilled water - but I also use a hose when flushing out lines, so I know there's still some tap water in there.

The last time I flushed the system, I also replaced the thermostat - so I was able to get direct access to the line that feeds the rear heat. I flushed it out as best I could.

It took me awhile to get all of the air out of the system. I ended up driving up and down some local hills, stopping periodically to top off the system.

09-28-2006, 03:12 PM
Alright guys, thanks for that. I went to Ford today and got 2 big jugs of collant, the thermostat and gasket....for $77CDN!!!! yikes.

Now, the guy there wasn't sure what I was talking about with the chemical flush stuff suggested by the Ford procedure so I got some Prestone flush over at Walmart. I'm having second thoughts on this though.....should I give it a try along with the flushing process (garden hose in my case)?

09-28-2006, 06:06 PM
It really depends on what condition your system is in. If you remove the thermostat and inspect it for rust and crud ... and find none, and if you drain the radiator and don't get a whole bunch of crud or solids there ... I wouldn't even got through the exercise of flushing (but that's just me ... guess I haven't had many coolant issues over the years).

But if you find crud and rust .. I would use every chemical weapon I could find to clean it all out!

And then refill with a anti-freeze rich (65% or so) mixture.

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