To flush or not to flush?

[J&T's 82]

I just got a low mile 95' Chevy pickup that at one time belonged to my grandfather. When looking over the truck I noticed that the radiator was about a half gallon low on coolant and full of rust/dexcool brown. I have gotten all the old coolant out and was wondering if using Preston Super Flush or similar was a good idea on a system this old?

[shumpertdavid]

You will likely need multiple flushes to have a chance at the system ever being completely clean again. I generally start out with dawn soap. Put a few ounces in the system and drive it until it starts getting rust colored again, drain, flush, repeat. If we are into warmer weather then I just refill with water and soap until I'm happy with how clean the system is, then I go abck to a 50/50 antifreeze/water mix. The radiator and heater core will hold a lot of debris in the tubes and slowly releases it over time. Heavy sediment also settles in the block passages and gets stirred and moved around slowly as Rpm increases, hence the reason it takes a while to get it clean.

[UserX]

Get one of these and remove the thermostat temporarily. I hate orange DexCrap.

[UserX]

Make sure to run the heater on full blast to get the core too.

[Mysticcobrakilla]

Cascade (powder) dish detergent. The only way to go.

[shumpertdavid]

Make sure to run the heater on full blast to get the core too.

This only applies to vehicles with Hester control valves. Uou don't have to run the heater full blast, only have it in the heat position generally.

[theflammer]

Cascade (powder) dish detergent. The only way to go.

Very interesting; haven't heard this one. I gather you have done it before successfully ?

[sdun]

I've cleaned heavy equipment systems with Cascade powder. It will make it look new inside even after an oil cooler goes bad and fills it with oil. We use a whole box on a bulldozer that holds around 20 gallons.