I just recently picked up a 2003 Land Rover Discovery, and the previous owner used a 50/50 mix coolant. They also told me they added water to that. Meaning it is already a 50/50 mix and then they mixed that with water. They live in Seattle so the winters aren't that cold, so this probably wasn't a problem for them, but I live in Montana and the winters are much harsher. I am worried that this mixture will freeze in the cold Montana winter. I have read up a little on flushing the coolant out, but I am curious how far a should go with this? Should I just pull the plug and drain out as much as I can, and refill with 50/50 coolant and no water? Or do I need to go the whole nice yards and actually flush the whole system out with a hose and what not?

Any guidance on the best way forward to make sure I don't have this thing freeze and split over the winter would be helpful.

Thanks,

Lazerbrains

 

I used a flush called Zerex. Empty it, use a wet/dry vac to push out the coolant, then fill with flush and distilled water, heat up, cool, drain, and repeat with distilled water until clear. Then empty completely, again with the wet/Dry Vac, and fill with Peak 50/50, tank raised. Run it to 200. Let it cool completely. Fill the coolant bottle, run it and see how temps are with an OBDII Tool. Check the next morning for air at the bleeder screw, fill there if so.

 

If you don't know when the coolant was the last flushed and replaced it's a good idea to do so. Coolant should be flushed and replaced every two years in. It's not a difficult job at all, just somewhat time-consuming and messy.

You can also get an antifreeze tester like the one linked below for under three dollars to check what's in your truck now..

https://www.walmart.com/ip/TESTER-CO...STONE/16817506

 

Great! I ordered one of those testers and will see what it says. I have no idea when the last time it was flushed was. The vehicle has been pretty well maintained. But probably good to just do it for good measure. Is a shop-vac really needed for this process?

 

The block drains, if you haven't located them, aren't that hard to find. Having no idea what coolant/water mix was in mine I just flushed it by running a hose in the reservoir with the heater hoses disconnected, then through the heater core both directions, and finally pulled the block drains and let the hose run from the reservoir through the drains.