How effective is a power flush? (Cooling system)

i have not had a system stopped up as bad as you say yours is but i have used cleaner during regular maint. as a preventative and it seemed to work good in removing debris.when i used the cleaner i remove all fluid by removing bottom radiator hose and remove thermostat, flush system with a waterhose and refilled with water and cleaner and drove approx 50 miles or so and removed bottom rad hose and evacuated system do not use the draincock then i ran a hose from my water heater in the house and flushed hot water thru the block by placing hose in upper radiator hose allowing to drain at lower hose and then flush radiator by placing hose into rad. filler neckand allowing to drain at bottom of radiator. do this flush with the water hose prior to adding cleaner and after draining and also do this on a day where water wont freeze in system. replace thermostat with a stant super stat or mr.gasket 195* thermostat and proper mix of antifreeze and distilled water.....good luck and post results.

I am a ASE certified Toyota Mechanic and toyota of santa cruz.. (as if it matters in a ford forum!) and we do POwer flushes as a regular maintenance procedure. in my opinion yes and no... you will be able to replace ALL of the old coolant with a power flush.. we have electrical Power flushers at my work, but you will need some serious additives to break down any build up. I still say to go ahead and do it.. just make sure you pay attention on how you go about it so you don't run all the crap from inside you intake and motor through the fins of you new radiator..

The chemical cleansers work quite well. Just be careful to not leave them in there too long (beyond the instructed time frame) or you will ruin seals and have to replace, say, a water pump. Been there, done that. Don't take advice from someone just because their '93 Cobra is LOW miles and clean - they may still be retarded when it comes to the coolant system.

At my work, we use that machine that pushes coolant backwards through the system. It beats a drain+fill, but there are more effective ways to really clean it out, but because they are very time consuming, we just can't use them and be effective.

First drain all the coolant out, add water and some good cleaner like Prestone Super Flush. Drive the car around for a while with just this mixture, then drain again, do this again. Drain the fluid with the motor at operating temprature. Here is where it gets messy! Pull the upper hose and T-stat housing and run the motor while keeping coolant in the system with a garden hose. When it starts comming out clear, shut off the motor and then drain the water. Then pull both heater core hoses, and spray water from the hose into the heater core one hose, then the other, and do this until it comes out clean. Just spray in if from a few inches back, putting the garden hose right on the heater hose might break the heater core. Put a NEW t-stat in the car, and fill with a coolant mix using distilled water and coolant concentrate. This will get it as good as your going to get it.

I want to also empasize using distilled water or the pre-mixed 50/50 antifreeze. I read a lot about cooling systems last year and the use of tap water, any tap water whether it is from a well or city, is far and above the main reason for cooling system sludge problems and radiator/heater core failures.