Having just spent three long, arduous days trying to remove all sorts of shite from the depths of my radiator finning, I have the following comments to add to this.

Firstly, having, in a fit of petulance, read the RepROM (a first for everything), I note that they specify that the tube from the fluid container to the filling valve should be full of coolant before the work proper starts.

So, having obtained a vacuum of -9bar with my compressor and left it locked off while I made a pot of tea I confirmed that the perishing radiator was indeed not leaking as I had first thought. Of course, had I thought, I would have done a vacuum test before I removed and cleaned it, but hey ho!

Having connected up the coolant container I then cracked open the inlet valve and let the tube fill with fluid and then closed it off again and re-established the full vacuum. Then, when I opened the inlet valve there was no air in the inlet tube getting into the system. Knowing how fickle the K is about air in the head, this is well worth bearing in mind for those new to the job and indeed those of us who don't normally read the ifn manual...

It is also worth noting that despite holding a vacuum of -9bar for well over ten minutes, as soon as the radiator got hot and up to working temperature the top hose does start to leak if you happen to have forgotten to put the clamp back in place. Don't ask me how I know this. So blow is bigger than -9bar suck in this instance.

Also for those who are yet to try it, I can confirm that despite my initial doubts the SGS Foam+ as discovered by Rae, is indeed a very effective cleaner despite some folks not being convinced. It really does not like being applied to a wet radiator which is a bit of a bugger if, like me, you were soaking the radiator overnight in a tub full of water. I used my compressor to dry off the radiator as much as I could and then, once applied to both the back and front of the rad, I gave it about ten minutes to work its magic but this didn't produce much in the way of foaming action. I tried giving it a second dose on top of the first and this produced masses of foam which literally lifted the shite out of the fins and left it sitting on top of the foam. I guess that our radiators have more densely packed fins than the average domestic or commercial air-con system.

I used about 90% of the litre bottle over three days so at the going rate of about £20 off Amazon it worked out about 4% of the cost of a new rad.

I should also add that my radiator was not caked with cack in the bottom outer corners but rather it was solid in a band right up the centre of the rad. This was doubtless caused by my filling the 'ladder' up the middle with about a gazillion holes in a vain attempt to get more air through the rad. It did that but it also took about three agricultural harvests worth of mud and straw with it and they used to build houses with that...so I've now sent off for a hole remover to restore it to its OEM form.

Being overtaken by a car? Hmmm!

£210 for the valve check seems very reasonable. I shall file that under 'Interesting!'

You could try Behind Bars in Kenilworth. Andy Spencer the owner is trustworthy and competent. I'm not sure he's a K expert, but he's certainly worked on plenty of BMWs, so there shouldn't be any surprises in a K.

The trouble with K valve checks is that it's inherently expensive because of the time to strip the bodywork down.

You almost want to do a deal where you strip it, push it into workshop, he does the valves, then push it out and stick all the plastic back on. Probably wouldn't go down well with most indies though.

You can strip the bodywork and ride it to them. I did that when I had the K12 cleaned and sealed with wossisname...

Love the vids Ritchie, even the upside down bits, you just have to pretend you are the pillion and not the rider.

I drove the pass long ago in the car with a manic, speed-freak girlfriend and we got tangled up with a bunch of bikes who were trying, but not hard enough...

When we pulled over in a lay-by for a brew, some of the bikes pulled in and one of the guys came over and said 'You should ride a bike mate.' Well, I only had two at the time but I took it as a high compliment.

Honister used to be used as a selective (timed and competitive) section on road rallies back in the day and it was as scary as 5#/+€ in the dark, especially for the poor navigators!

I remember your angst at the time Rae. You were on holiday somewhere iirc. The West Country?

We all need to bear in mind (even those of us with a hoard of new radiators stashed away) that the K rad is aluminium- not copper-cored and has plastic side tanks which are crimped in place utilising tabs moulded in the aluminium. If these tabs lose their grip then the rubber seals between the ally and the plastic start to leak and then all is lost. This is how I lost the rad on my K12.

So it isn't just the crap that causes the overheating but it may also be eating away at the tabs. As may anything that we squirt on the rad in our efforts to clear out the crap...

Do you remember when you bought a new bike and only had to figure out where the reserve tap was...