Radiator Flush 98 Expedition

[Fitz98]

Hi to all.
I think the next thing I want to do maintenace wise on my 98 Expedition 5.4 is a coolant flush. I have 145K miles and don't know if it has ever been changed.
What is the best recommendation to flush the system?
Type of coolant recommendations?
Process recommendations?

 

[Trav]

Very difficult to do a complete flush on these with rear heat.
You need special tools to get the lines off,if you have the tool then taking the rear heater lines off will help.
The block drains are not easily accessible either and will probably be rotted in place.

Opening the radiator drain will yield about 2 1/2 gallons,
total system on mine was about 24 qts.
Removing the thermostat and flushing it through then blowing it out with compressed air worked okay.

I use Peak Green on these,they came with Green OEM.
Ford did back spec G-O5 for these but you probably wont get enough of the old stuff out to do a proper conversion,the green is safe.
I drain the radiator only every 2 years and refill with green and it stays nice.

 

[Fitz98]

So here is what I was thinking...
The whole syatem is 20.8 quarts (5 gallons) per the owners manual.
If the radiator holds 2.5 gallons, then I thought I could buy 10 gallons or so of distilled water, drain the rad, put in 2.5 gallons of water plus a rad flush treatment.
Run the car until hot, with front and rear heaters going to circulate that old coolant out of the cores and lines. Cool, drain, repeat.
Keep repeating until running clear.
On the last one drain the radiator and refill. That should be about a 50/50 mix if the radiator holds 2.5 gallons.
Does that sound like it will work?
I will search for the Peak Green as you suggested.

 

[doitmyself]

That will work. It is a very slow process since it takes a while for it to heat up enough to open the thermostat. I also found that even with five fills and drains, there was still a trace of coolant in MY system. It varies by vehicle, but have a plan in place if you decide you need even more distilled H20.

The Zerek Flush (not Cleaner) advertises that whatever is left in the system is safe, but I have no way to confirm that.

At that age, you might consider a thermostat replacement. I push mine probably longer than I should.

 

[Fitz98]

It seems like it is easy enough to drain at the radiator, and recently I have plenty of time, so I can do plenty of drains and flushes over a few days until it runs clear.
Are flushing chemicals good, or over rated? Ay that are prefered?
I think the T-stat change is a good idea.

Just had a thought, what if I remove the T-stat just for the time I am flushing the system? In theory, the water would be circulating all the time cold or hot right?

 

[Trav]

Yes it will,good idea!

 

[AdRock]

To flush the block and heater core out I usually remove the thermostat and shove the garden hose into the upper radiator hose and let it run wide open to backflush everything out the bottom.