Hi All,

I love my new 07 frame.....There's quite a big difference in geometry and it seems to turn a lot tighter now too.

But I have just one last problem to solve.....There is coolant dripping out of the radiator cap over flow pipe while the engine is running....?

I did not disconnect any radiator hoses at any time. But during the radiator refit the plastic right-angled pipe on the radiator cap popped off. I could see it was a simple o-ring seal snap fitting so I just popped it back in again.without any fuss. But I'm concerned now that there might have been a ball bearing or a spring that popped out too.

Does anyone know how these caps work or have any other ideas what might be causing this?

Best of balance.

Neo

Edited February 18, 200917 yr by Neo

Did you fill it right to the top with coolant ? if so it's got to have some expansion room, and will drip a little until it finds it's correct level.

The tube doesn't have a check valve in it.

I could not resist a look at this little KTM 50 that one of my guys has sitting at the shop today. It has the same setup on the radiator cap so I popped it off, nothing there on the top elbow, as it seems the main relief spring and valve are in the larger part of the cap.

Ishy's point is valid, as you just need to cover the cooling coils and top plate in the radiator and leave a bit of headspace for expansion, as anything else may be expelled anyway.

I've found with the new KTM radiators you can run the water right up to the base of the filler neck and they don't spit any water out, so not far off full.

Maybe you should try a new cap, there about

The radiator was not drained or topped up during the frame swap.

But one thing I did recall was the overflow tube was previously routed in a way that made it kink near the spout. I checked my other bike and it was also routed in this way, with that kink. So just for the hell it I routed the tube the old way and hey presto the drips have now stopped...go figure that!?!

Best of balance.

Neo

I happened to spot the little overflow hose on the floor next to one of my favourite rock steps! I've clicked it back into place, but wasnt sure where the overflow pipe should be routed (or if it really matters)?

It doesnt seem to be a very good design as it fell of by itself leaving a hole in the top of the filler cap! Not sure how long it had fallen off for, but no coolant seems to have been lost.

I doubt it would just fall off, probably got knocked off or dislodged last time somebody filled the radiator maybe even at the factory if it's a new bike, then over time it has made its way down past the frame and radiator on to the floor.

The cap has a sealing washer with a pressure relieve valve in it so it doesn't matter if it has the tube on or not, the tube is just to safely divert the hot steam down the side of the frame if the engine over heats.

Shows how much I know!!!

I routed the tube the old way and hey presto the drips have now stopped.

Hmmm...... It's still dripping, just very slowly.....looks like I need to buy a new cap.....

Thanks gents.

Best of balance.

Neo