What's the best thing to clean a radiator?

[fordperv]

The radiator for my capri looks pretty grim inside a kind of sludge orange colour, I was wondering what the best thing would be to clean it with thats effective? Or theres an old school radiator guy down the road should I just take it to him and ask him to do it?

[Shep Shepherd]

I'm told that cellulose thinners does a good job, although I've not tried it myself.

[Mr A Lawrence]

Xdishwasher powder/tabs work well.

 

Plug the hose holes and mix some in boiling water and tip it in.

 

Leave for a while then flush well.

[PiperCub]

^^ Not tried it myself but that's what I've had recommended, it may need two goes though. Also, don't know why but was told the cheapo stuff works better. 

[Tamworthbay]

I used bilthamber deox c to get rid of the rust then dishwasher tablets to clean out any other crap. Worked well on my Capri . It sprang a leak six months later but I am 99.9% sure that was unconnected.

[DodgeRover]

Crumble dishwasher tablets into water (flush the antifreeze first) and run for a while then drain and flush again

[somewhatfoolish]

If you've a rad bloke nearby then taking advantage of their cleaning tank is a good idea.

[Uncle Jimmy]

If it's making hot coolant colder I'd leave well alone!

[sierraman]

Fernox works well, it's designed for high temp central heating systems.

[Snipes]

Radweld.

[MikeR]

white viniger and heat ....

[jonny69]

It'll probably spring a load of leaks once you rinse it out. Don't let that put you off.