I did a coolant flush on my '04 Disco a few days ago. It had Dexcool in it and I feel confident that I got all the old stuff out by flushing it several times. The last flush I did with distilled water.

Before I refilled the system, I drained as much water out as I could by lowering the disconnected bottom radiator hose until water no longer came out. I assumed that I likely didn't get all the water, so I put in a mix of about 60% Prestone to 40% distilled water. I was able to get about 1.5 gallons of this mixture in. After driving it around a bit and purging the air out, I got about another .25 gallons in.

I checked the boil-over point with a Prestone hydrometer. It said that I was protected to 259F. A 50/50 mix of Prestone should give protection to 265F. So it looks like there was more residual water in the system than I thought. Do I need to be concerned or is this enough protection? Oh -- I did add a bottle of Water Wetter too.

What is the best way to remove all of the water after doing a flush?

 

https://landroverforums.com/forum/di...ce-life-49082/
There's talk in here of hooking up an air compressor to flush all the water and coolant out. I'm going to try it in a few months when I flush it again.

https://landroverforums.com/forum/di...en-hose-45250/
This link is a good write up on how to flush with water from Savanah Buzz. I would follow steps 3-7, except use a compressor and maybe a blow gun attachment for the individual hoses.

I think without pulling the engine drain plugs, you're probably going to have a little water/coolant left over, regardless of how you do it. I've heard they are tough to remove, and it's not worth it for the little thats left in the engine.

 

The ideal way to remove all the fluid is by using a vac. system designed to remove all the coolants and then when reversed, it will re-fill your system leaving no air anywhere in the system.
You should have replaced both the t/stat and the coolant pressure cap when changing out your coolant cause Dexcool eats them up. I also recommend adding a bottle of either Water Wetter, Purple Ice or BG's Super Cool to your system for better heat removal.

 

DiscoMike -- yes, I did replace the t/stat, cap, and added a bottle of Water Wetter.

What are your thoughts on the mixture as it looks like I am under a 50/50 ratio since the max temp is 259F (measure with a hydrometer) instead of 265F (this is what you get with a 50/50 mixture). Am I being overly paranoid or should I remove some of the mixture and add straight coolant to get the max temp up to 265F?

 

your fine; if you cooling system is working properly you will never see temps that high. And if your motor does get up that high it's probably toast anyway.

 

2nd this. I am unending the peak 50:50 and have not seen over 207F. I added a bottle of water wetter after and I seem to top out at 204-205F. I am not sure if it is because of the additive, or the 207F was an isolated incident

 

What he said, you are to worried about heat, what is the freeze protection, that is the question.

 

Sorry for the late response -- but I just did a quick weekend trip to Moab to check out the new Disco. I am very pleased with its' performance!

The hydrometer states that my freezing point is -7F. It gets to maybe 0F here a few nights a year here in Salt Lake City -- so I should be good.

Thanks for everyones reponses!!

 

ummm - with wind chill while underway on cold day, you could slush up the radiator. Need more anifreeze.

 

That doesnt seem right for a 60:40 mix.