radiator flush

[Phantom]

G'day al, Now i know this aint all that technical and might sound like a really really dumb question , but i'm not scared to ask. What is the best way to flush the radiator / motor out? and what type of coolant(diluted i presume) do i use to replace the rusty dirty water in my radiator/ motor ?
                  Cheers (Dumb) Rusty

[Glenn 'Stinky' Stankevicius]

Better to ask a dumb question than make a dumb mistake.

The use of coolant is more complex than you think.
I have been told and so far it works.
If you cooling system is good, do not use coolant but an anti-corrosive additive. The gear I got was green and looks like traditional coolant.
Coolant raises the boiling point of the water in the system, but it does not dissipate heat as well as what water alone will.
You will probably get a different story from a coolant salesman though  

[Glenn 'Stinky' Stankevicius]

as to flushing the motor/radiator, there are two schools of thought.

1. Don't back flush (pressurised water in the opposite direction) or you can block up the water passages with the junk that's in there.

2. Do backflush to clean out the max amount of crud.

If I was doing it, I'd pull out the thermostat and flush it out with the garden hose, then refill with water and anti-corrosive.

[Phantom]

Thanks Stinky
                            Cheers Rusty

[mcl1959]

Rusty I found that no amount of flushing or high pressure water would get all the gunk out of my motor.  What I ended up doing was removing the manifold and taking out the 3 welsh plugs along the side of the block.   Once I spryed the high pressure cleaner in the holes (especially the back one) I couldn't believe how much more sludge was still in the block - and this was after I had used radiator/block cleaner and taking the thermostat cover off.
I would have liked to take out the rear welsh plug as well but this is much more difficult to do.
All it costs is 3 welsh plugs and a manifold gasket - about $20

Ken