Flushing the cooling system

[CoupeWannabeS2]

Has anyone got any good suggestions on products for flushing / cleaning the cooling system?

Is Holts Speed Flush any good, or are there better products?

[newsh]

Barrs or Wynns stuff is ok but a flush through with clean water is usually good enough. If you have oil in there then crumble a dishwasher tablet into the header tank, fill with water, run up to temp for a few minutes then drain and flush through again before adding antifreeze and topping up.

[Error404]

Buy some oxalic acid crystals
Dirt cheap and its what most rad flush products consist of. I understand it reacts with iron oxide (rust) to hold it in solution so it breaks down deposits really well. The colour of the water afterwards is foul!

[CoupeWannabeS2]

Thanks for the replies, much appreciated.

[CoupeWannabeS2]

I am also looking to clean out my dirty expansion tank. I have made a start by getting boiling water in it, along with a dishwasher tablet, then shaking it up. This has helped, but there are still some stubbon areas of dirt.

As I cant get into the dirty chambers, I am struggling with these last areas. From an internet search I found some comments that you can put dried rice in, and then shake it around to clean the insides of the tank. Has any one tried this?

Clearly I dont want to get a load of rice stuck in there - as that isnt going to do the cooling system any good!

[220bhp]

Dan I don't think a new expansion tank is that expensive, but as Alex said you can use Oxalic acid crystals from the chemist. I use it as a bleach when restoring furniture.
You can make it with hot water so the crystals dissolve. Make sure you flush it out properly with cold water, and wash your hands as its a poison. The same poison that's in rhubarb leaves.

[CoupeWannabeS2]

Dan I don't think a new expansion tank is that expensive, but as Alex said you can use Oxalic acid crystals from the chemist. I use it as a bleach when restoring furniture.
You can make it with hot water so the crystals dissolve. Make sure you flush it out properly with cold water, and wash your hands as its a poison. The same poison that's in rhubarb leaves.

I plan to carry on with the cleaning efforts for now, as it is getting cleaner inside.

Failing that I will get a new one. I note from another thread to avoid any pattern expansion tanks such as the Febi ones which can swell up.

[GazzaG60]

expansion tank-use petrol. works a treat.

[veneto rs2]

Best thing if you want to do a proper flush of the whole cooling system it's to do it without the thermostat.
If you leave the thermostat in situ there's no way you can flush out everything that's inside.
Yes with proper products as the ones correctly mentioned you can clean the gunk but to flush it out with running water you got to do it without the thermostat

[CoupeWannabeS2]

Thanks for the comments everyone. Hopefully get out and work on the car again in the next few days. The expansion tank cleaning is coming along, and I dont think it will need to be replaced.

When I get to flushing the whole system, I will give it a go with the thermostat out. I'm sure the out door tap will come in handy that day!