To flush or not to flush....

[riverman]

As part of my restoration and overhaul of my 44 GMC, I am debating whether or not to give the cooling system a full flush with an additive to give it a good clean out. I've never had any problems with the cooling system in the three years that I have had the truck and I've been assured that the rusty looking water that courses through the system isn't anything to be alarmed about.

 

However, I would like the peace of mind that all the fluids are tip-top but I've heard a couple of horror stories about people flushing their systems only to find that the core of the radiator has been wrecked in the process - I suppose this would suggest that it was on its last legs anyway but I'd appreciate any advice - should I do it at all, what additive if any should I use etc etc.

 

Thanks in anticipation

[N.O.S.]

I guess some flushing additive might potentially cause damage to the rad core but as you say it only finds weak spots which would eventually fail. I've used additive on a couple of occasions without problems, but admittedly the radiators were in very good condition.

 

Best way I've found is to constantly alternate between flush and reverse flush with a really good flow rather than just one way flush. It seems to be this flow reversal which does more to dislodge accumulated deposits than anything. And keep at it - it took 1/2 a day to clean out a Rolls C6 diesel block and cooler - I couldn't believe the almost constant flow of rusty water!!!

 

Of course a good flow helps - a 1" hose on my 6" water pump gives a marginally better flow than a domestic tap But I'd certainly stick a pressure washer outlet on the block - just be gentle with the radiator!

[Tony B]

A gentle flush won't do any harm. I'd then add fresh coolant with K Bar conditioner. The K Bar will keep things sweet.

[Marmite!!]

I'm just making up some adapters for my Power Flushing Machine I use in my business, it uses a high volume, low pressure pump with reversible flow & hot or cold descaling chemicals. it flushes straight to drain & any metallic particles are caught by the twin magnetic filters.. I can descale & clean a complete central heating system in about 7 hours so should work well on a vehicle...

[N.O.S.]

I bet that finds a few heating system leaks Lee :cool2: You're right, it would be the mutt's nuts for vehicle use.

[rambo1969]

If it ain't broke, don't fix it!

[MARTIN CROSS]

Hi

I always put water wetter in to improve the efficiency of the cooling system.I think Halfords and Frosts do it.

I had a V12 Jag and that never overheated even in heavy traffic or queues.

Martin

[riverman]

Good advice, guys -thank you - I'm inclined to go with the "if it aint broke dont fix it" for the time being and I know what to do if I get any problems!