Hi everyone,

I’ve had some different types of coolant in the cooling system of my DII and I think it’s time to correct that. The weather here has a typical range of 30F to 85F with average days being around 75F in the summer.

I’m wondering if there’s a generally accepted ideal coolant for these vehicles? I've read all sorts of suggestions, like use Zerex or just use any green stuff, or only use the real LR fluid, but I figured I’d check and see if that’s changed.

I’d plan to get concentrate and dilute it with distilled water. Is there a ratio you use or a ratio you’d recommend for this climate?

I’m also wondering if there’s a best accepted method of draining the system?

The system hasn’t been cleaned in a while (I’ve never done it) and I’m wondering if I’d just run hose water through it to clean it up, or if that would be a bad idea? I have lots of bad ideas, but I try to check before going through with them.

I hope everyone is well. How about this heat?

Also, is it an old wives’ tale that it’s good to run the heater all the time, even -and especially- in summer? Or will this start to break the heating system, so I’ll be screwed when I’d actually like it to work?

 

Does anyone have any suggestions for this? I've seen a lot of information that is either conflicting or probably isn't specific to a climate like the one I'm in.

 

I think your're over-thinking it. I use regular green Prestone, 50/50 with distilled water and pull the lower rad hose to flush it every 2-3 years. Done and done.

Others may have different ideas.

 

Yeah, definitely overthinking it. Low cost green coolant 50/50 is fine.

 

Drain the radiator, pull the block drains on either side and fill with water, run and bleed, run and bleed, run and bleed. Then start over. Do this as many times as you have to until the stuff you drain out looks like water. Then fill with pre-diluted green antifreeze, I use the Peak Asian formula green, because its REALLY green. But I think any green will do.

 

Pull the lower hose from the radiator and let it drain. It'll be messy; be sure to use a BIG catch pan.

Refill with water only. Some people say to use distilled water. Distilled water is very inexpensive so use it if you like.

Repeat the process as many times you have until there's no visible color left. For my truck that usually takes 2-3 cycles. At that point the system will be very, very close to having water only in it.

At that point, drain it again as completely as you can and refill with Prestone concentrate, not the 50-50 mix. That will give you, with the water that's left in the system, very close to the 50-50 mix that is your target.

 

on these trucks the coolant is always flowing through the heater core.

 

Thanks - I'd heard that green coolant types shouldn't be used and that it was more of a reddish-pink coolant that's intended to be used here.

When you flush the system, do you mean you just let it drain or do you use distilled or hose water or some other kind of flush?

 

So that means running the heater in the vehicle helps the system cool better, or that doing so is pointless?

 

@neuropathy well cranking to max will turn off the AC, and with the fan on max you will get a bit of additional cooling so it helps a bit. Ideally a manual switch for the AC fan would be more helpful as it would move more air if you are moving slowly along a trail.