Radiator flushing - should I use Rad flush compound?

Hi - I’m flushing the rad and renewing the coolant - the Haynes says use a Rad flush compound to clean everything out.

I can’t find any Rad flush which says it is suitable for motorcycle engines in Halfords (rad flush for bikes because of the aluminium components). Anyone know anywhere that sell bike specific rad flush.


Not sure what is special about bikes. Most cars have aluminimum engines these days.

Yeah - I think it’s the Haynes being ultra anal as usual - i’ll just stick the hosepipe in the rad and flush it with that.

+1 Good old tap water is quite sufficient:)

Bloody Haynes, complicating things as usual! :wink:

Exactly what I went through when replacing the coolant. Haynes said rad flush, but a bit of digging round on t’internet convinced me than a tap and hose pipe would do just fine.

If you want to thorough, disconnect the radiator to engine hoses and hose wash each through separately.

Then again, if you’ve looked after the cooling system and the bikes under, say, five years old it’s all a bit of a waste of time. It’s a sealed system and if it’s had the right stuff in it there it’s most unlikely there will be any muck of any cosequence in there.

I think I might follow the thorough route oldguy - the ZX7R is 9 years old and was previously owned by some guy who thought he’d just rag the arse off it and never bother with simple niceties like regular servicing.

Consequently I’ve been gradually nursing the bike back to health - sorting out the cooling system is next on my list - I was keen on using the rad compound because I’ve got a sneaking suspicion the bike has never had it’s coolant changed - just topped up* As you say - it is a sealed system so hopefully it will be relatively clean.*In the same way that it appeared to be running on the original set of plugs!

Hmm. 9 years old, poor maintenance. I’d give it a chemical flush through.

The days of different flushing chemicals for bikes and cars have long gone. Cars have caught up with bikes, so the Halford products should be o.k. Just check the concentation levels as cars have much bigger coolant volumes than bikes.

Yeah thanks Oldguy - I guess they both use aluminium components these days - cars and bikes.

I would too, with a two part flush agent. I’d also take the radiator off to clean it out.

Yep - I think i’ll go with a proper chemical flush and clean the rad/hoses after all.

Better yet, take the chance to change the hoses. And all those iffy clips.

If they’re 9 years old, they’re due a change anyway.

(And there’s not a lot worse than putting cash and TLC into a job and then being let down by the ungrateful beast. Fair ruins your day.)