When I had my valves checked a while ago the garage told me that my waterpump was leaking (they removed radiator for access and replaced coolant) but that it only leaks when the vacuum is removed i.e. when disconnecting the radiator.

If it doesn't leak during day-to-day use when the cooling system is all connected, should I worry about fixing it?

When you say leaking do you mean leaking from the drain hole underneath the waterpump?

i changed the seals on my NC29s water pump in the 1st year i had it. no way you need to go anywhere near the rad to remove it! its sat on the LHS of the bike just above the main side casing.
2 seals, non-OEM

cbr400rrn wrote:When you say leaking do you mean leaking from the drain hole underneath the waterpump?

Yes that's correct.

leopard_pagan wrote:i changed the seals on my NC29s water pump in the 1st year i had it. no way you need to go anywhere near the rad to remove it! its sat on the LHS of the bike just above the main side casing.
2 seals, non-OEM

They removed the radiator to gain access to the head as they were checking the valve clearances.

Had a leak on one of my bikes and had to replace the whole pump as you cant buy one particular part and cost quite a bit of money. One side is a mechanical seal and the other seal is o ring, theres two seals to keep the oil and water seperate so if one of them fails the other i guess is a type of back-up and the hole is to warn you that one of the seals has failed. It is up to you what route you choose to go down but ask a mechanic what they think.

I think I'd rather fix it - how much did the pump cost you? Assuming you bought new. I'll try to get a good second hand one.

I have a few good tested / cleaned used NC29 and NC23 (Tri Arm) water pumps in stock @ £35 each delivered - to UK postcodes.

Hope that helps - paypal as per signature email is quickest.

Get it fixed....

definately fix it, before it develops into engine failure etc!!!..ted

There he is
To double-check it, removing the rad cap should allow the coolant to leak from the drain hole right?