How complete of a coolant flush is needed?

[Petesexpy]

I did just the rear heater core flush on mine last Sunday using a 3-gallon bucket. Took 18 gallons and only the last bucket was free of rust. I ended up pinching the garden hose and releasing the pulse of water after my 3rd bucket was clear. Took additional 2 buckets to clear. And that's every year...

 

[jr1under]

And that's every year...

Earlier in this thread you said you'd learned your system was always going to be full of rust no matter what you did. Is that because of salt infiltration every winter or is the rust something that goes on forever once it starts?

 

[Petesexpy]

Earlier in this thread you said you'd learned your system was always going to be full of rust no matter what you did. Is that because of salt infiltration every winter or is the rust something that goes on forever once it starts?

It seems to me it just goes on once it starts. Just inherent to the 1st gen expeditions.

 

[jslt]

After a few days of driving, the coolant filter seems to be keeping the fluid in the gas bottle a bit cleaner. Once my replacement filters arrive I'll do a full flush and see what comes out. The weather just got real cold here and having heat has been very nice!

I am going to switch Zerex GX-05 coolant when I finally add it in. The green stuff that was in there didn't seem to be doing a very good job.

 

[JamaicaJoe]

I have a 2001 that is a Florida vehicle. The radiator support rusted out which is very unusual as there is little to no rust anywhere else. I suspect there may be some sort of electrolysis going on with respect to the aluminum radiator core and everything else that is iron or steel. Once I get all that sorted out I am going to measure for stray current. It is tricky to solve that problem as simply shorting it out might make things worse somewhere else.

 

[jslt]

Just a quick update. New filters arrived so I got around to doing one more flush of the distilled water and then replaced the coolant filter. I hooked up the rear heater core and I went ahead and put the GX-05 coolant in so I can finally stop worrying about parking outside in the cold.

Everything is working, but not getting any heat out of the rear core, so I am slightly concerned that the filter is reducing the line pressure too much for effective rear circulation. It may just need a few cycles to purge the air out of the system so I haven't given up hope yet. Front heater core is working great and now I am on to the next gremlins with this car (heated front seat not working).

 

[jr1under]

Just a quick update. New filters arrived so I got around to doing one more flush of the distilled water and then replaced the coolant filter.

Any change in the amount of rust that came out from the flush?

 

[jslt]

Any change in the amount of rust that came out from the flush?

It seemed like very few flakes/chunks came out, but the water was definitely cloudy. I’m going to run the car for the next year and then do another full coolant flush next fall and then maybe keep on a two year cycle after that.