Changing coolant and flushing system

[Greg]

I'm changing my gf's coolant this weekend.

It's very rusty and sludgy so I got a bottle of radiator cleaner. You add it to the coolant, run engine for 20 min, drain the coolant and then it says to flush the system.

How do I flush the coolant system?

I've been reading that reverse flushing the system is the way to go - so do i just stick the hose up the drain plug and crank up the pressure or what?

Thanks guys

Greg

[gatty]

i thought it was best to remove bottome hose and run the garden hose into top?

anyone clear this up

[Greg]

yeah i 'm confused!

[Jordan]

I saw its best to disconnect the top pipe, have the engine running at idle, and just fill the radiator with the garden hose at the same rate that it empties. When the water coming out turns clear its done. Let the radiator empty a little so theres space for the coolant.

I wonder how UAS do a flush? I read on their site that they only use demineralised water, dosent come from the tap

[snake]

On the side of the block there is a plug to drain the water from the water jackets around the cylinders, dont know if people actually do this or they just do similar to what you have mentioned. In the work shop manual it recomends to undo the plug to let the water drain from there as well as from the radiator hoses.

[nedb]

I did mine as snake just mentioned. Undo the bolt on the side of the block get a hose into the radiator and flush it all out.

This way you flush the whole system instad of just the radiator.

[performance-wise]

If you got rusty water then you might have to replace your hoses aswell.

Give em a squeeze and if they sound and feel "crackly" then you have a build up on em and probably should replace em.

[GIGOLO]

Another way would be to remove the the Thermo housing (and while its out test the Thermo) and run the pressurised water into the radiator and through the engine. If you have access to an air compressor you could flush out the water after with the air, then reconnect everything (you will need to use a silicone gasket to reseal the thermo housing) and refil with appropriate water and collant.

Cheers

[Jax]

To remove gunk from radiator, it is obviously best to reverse the water flow through it! Normally, the water flows from top to bottom. If you remove the radiator cap, and the bottom hose, and use a garden hose from the bottom [preferably sealed as much as possible - wrap a rag or something around it.., it will remove UPWARDS that which has lodged in tubes from above.

The thermostat will stop flow to other parts, so that this will concentrate on cleaning rad. Then use other suggestions to flush out block,etc. Think about where the flow is going when you're doing these things, so that you don't dislodge rubbish from,say, block,and deposit it in radiator.

Remember that larger pieces may be dislodged than can't pass thru radiator tubes, so you can actually make it worse, if you're not thinking.