Rad Flush - antifreeze question

For systems that have rusty looking water I used to use DuPont 2-part powder anc flush repeatedly. I tried liquid flush sold by Caterpillar dealers and it worked way more effectively than mouse milk sold in parts stores. The EPA apparently likes sold to consumers stuff that is environmentally friendly I guess.

Thanks for the tips! Seems to be fine after a few days of commuting. I have picked up a new thermostat and will definitely flush twice.

My next question is how do you drain the heater core of all its garden hose water? I will be using distilled water and concentrated coolant to fill the system, but I want to remove as much tap water as possible. Should I just be able to disconnect the heater hoses from the engine block to blow out the water inside the heater core?

I use Prestone Radiator and Flush, which has similar directions. I did not want to spend that much time so I just took about a 1-2 hour drive. Drained the water/flush coolant and refilled with water. Drove about 15--30 minutes with the heat on, then drained that water. Repeat. YES, a second clean water flush.

Most modern engine have no way of draining the block so there is still a lot of clean water in the block. Looking at the total cooing system volume (owner manual) I calculated home much 100% antifreeze should be in the system.

I double checked the antifreeze concentration the next day after another 1+ hour drive. It was actually too high, so I removed about 2 quarts and add that much water back.

A few months later I had a mechanic ask how did I get the remote coolant reservoir so clean for an 17 year old vehicle.

I don't know what engine you have, but the Cummins diesels are sensitive to the type of anti freeze needed. Be sure to use exactly what the manufacturer recommends. Temps only slightly below freezing shouldn't matter for overnight sitting time. If worried, throw a trouble light under the hood to keep the chill off until the flush is finished it's cycle and replaced. Don't forget a thermostat change at this time as well. After going through all the trouble to replace hoses, flush and fill, it's something that should be considered. A new radiator cap may be another item you could consider changing now too.

Other than the darn hazordous chemicals you have to dispose of, why not simply drop it off at a radiator shop, have it serviced and take it home laater the same day?