coolant flush

[john cris]

I'm fixin to replace a leaky radiator, water pump, fan clutch and upper and lower hoses. The T-stat and housing were replaced about 10K ago as well as the coolant temp sensor. I'm going to use a 60/40 mix of Napa (antifreeze/distilled H2O) and Redline water wetter. This is a 2003 4.0 SOHC motor with original water pump and radiator with 150K. Are those back flush kits really that effective? What else needs doing?
Thanks,
John

 

[Number Twelve]

It has been my experience that the radiator passages act as filters for the debris, so that is the primary target. The usual flow through a radiator is rather generous, so most debris will be found there. Any that isn't found there has settled somewhere inconspicuous to the velocity of the normal flow. For instance, some particles at the bottom of the cylinder jackets will usually stay there indefinitely and your flushing activities have a low probability of exceeding the natural flow rate, but you're welcome to try.

In days of old, the, "pros" used a recirculating pump with some serious chemical content. One place where I worked had a huge vat where the radiators were boiled over night. The next day, the leaks were soldered shut because the passages were a copper alloy and would accept lead solder. One ingredient would be oxalic acid. I would be fearful to inflict such corrosive contents on modern radiators. I would back flush the radiator and expect some particles to be carried out of the radiator simply due to mechanical forces.

Now that there is a mix of ferrous metals and aluminum exposed to the water flow, and computer aided design has accomplished removing all possible excess quality in the radiator fins, a proper flushing solution is no longer a cup of non-foaming detergent and a pound of oxalic acid. I guess somebody makes a proper flushing product, but I don't know what it would be. I would just rely on the water velocity for my first attempt. Only if the radiator refuses to surrender its load of particles and the engine is in danger would I try something more chemically active.

ps, Don't neglect the heater core(s). They need to be addressed separately in order to get a good velocity flush.

 

[john cris]

I'm surprised the heater core should be flushed separately. I was going to install a back flush tee on the inlet to core and use that to cycle water through the system. I will also remove the T-stat during the flush. Man this is going to use a lot of water.
Thanks for the help,
John

 

[lincolnshibuya]

I'm fixin to replace a leaky radiator, water pump, fan clutch and upper and lower hoses. The T-stat and housing were replaced about 10K ago as well as the coolant temp sensor. I'm going to use a 60/40 mix of Napa (antifreeze/distilled H2O) and Redline water wetter. This is a 2003 4.0 SOHC motor with original water pump and radiator with 150K. Are those back flush kits really that effective? What else needs doing?
Thanks,
John

I'd recommend zerex than using generic coolant. I've seen lots of neglected cars/truck which turns to rust or corroded because of bad coolant (or some nearly water concentrate) redline water wetter is just pure advertisement crap.