I have just changed the gasket on the waterpump (I hope it was the gasket has gone, but I have a feeling it might be the seal, as water is coming from one of the holes I don't think it should.

(it's a 1.8 waterpump mated to a 2.0 zetec engine)

Anyway, upon fitting the whole lot back together, The cambelt works it's way off... and Whatever I try, it does the same.

Has anyone any idea why idea it does this? Or if I need a new water pump?

The pump is only 400 miles old... so would not be best impressed if it needs replacing already!

Thanks

Tom

sounds like the bearings have gone in the pump allowing the cam belt pulley to run on the skew throwing the belt off

Do you mean the cambelt or alternator belt? If you mean the alternator belt then I too suspect the water pump bearing. I had a pump go after 3000 miles, I put it down to too tight on the belt, but then it was a Halfords part so might just have been crap!

There's definitely something wrong with the water pump or its mount. I suspect there's a noticeable misalignment of the pump's pulley with the rest of them, causing the belt to "go off the rails". This could be caused by the pump's bearings failing (which could cause the pulley to cant to one side, giving misalignment), or by the mount itself. If the pump is leaking as well, it sounds like the whole pump is due for a holiday at the rubbish tip!!