Coolant...

[Qwazert]

Thinking I should probably change the coolant this summer...don't know when (or if) it was last done.
So what is everyone using for coolant, and how much will I need?
Is it OK to add new coolant to older stuff...I can't possibly drain ALL of it out!

[nra1ifer]

You CAN and MUST drain the old out, flush the system, and put fresh coolant in. I use Tractor Supply's FleetCharge in my 1995 PSD. Plan on buying a couple of gallons of coolant, and 8-10 gallons of distilled water. After you drain the old coolant, you'll use distilled water during the flushing process, and when you finally fill the system with the new coolant.

I'd have to do some looking, but there are write-ups for the entire process readily available. Don't scrimp on something as important as your PSD's cooling system.

[351fifty]

They sell coolant flush kits at napa, I actually poured distilled water in the heater core hose till I was satisfied with the flushing

[JD3020]

I've been told by multiple mechanics(gas and diesel) that you don't have to get 100% of the old coolant out, if your staying with the same type(generally color) of coolant. If your truck has regular green coolant, and you wanna switch to red ELC, then you must do a complete flush. But its still a good idea to do a complete flush either way, and use a chemical to help break up any crap that is in the system.