Cooling System OH Rust In Fresh Fluid; Next Steps

Bratch

TJ Enthusiast
Supporting Member
Joined
Jan 22, 2018
Messages
113
Location
OKC
Our LJ has been getting hot at idle. Yesterday I replaced the aftermarket radiator with a new Mopar radiator, I also replaced the lower radiator hose, and both heater core hoses. I had replaced the upper hose, water pump and thermostat over the past 2 summers.

Prior to replacing the radiator I did a slow Prestone flush and a fast Prestone flush the day of the swap. After replacing everything I’ve ran distilled water and drained to check and still have rust in the water.

What should my next step be? I’d planned to run distilled and flush every couple days until it cleaned up but I suspect there is a chemical treatment that would help.