New Water Pump

V Mad · Post by **V Mad** » Mon Oct 03, 2011 3:39 pm

A long time back I bought a spare water pump. It was new, boxed made by Airtex, USA.

I am now trying to fit it, but I find that the impeller fouls on the inner pump housing when offered up. The reason is that the impeller protrudes about 12.5mm compared to 10.5mm of the old pump.

I am pondering whether to fit a thicker gasket to fix the problem. I can get hold of some really thick proper fibre gasket material. Or are there shims I can get?

Any helpful suggestions/comments would be more than welcome.

bigbob · Post by **bigbob** » Mon Oct 03, 2011 4:57 pm

You also need to check the position of the fan mounting flange. It may need pressing to the correct position to stop fan hitting the rad. May also be a problem if you shim pump forward to clear impeller.

V Mad · Post by **V Mad** » Wed Oct 05, 2011 7:24 pm

bigbob wrote:You also need to check the position of the fan mounting flange. It may need pressing to the correct position to stop fan hitting the rad. May also be a problem if you shim pump forward to clear impeller.

I have already set the flange to the correct dimension, but I need to sort out the impeller clearance problem. I seem to remember some pumps had a backing plate, but I cant remember if I took one out last time I removed the pump, if so thatr might be the answer. But I will probably need to turn everything upside down in my workshop and shed to see if I have one.

V Mad · Post by **V Mad** » Sat Nov 26, 2011 3:03 pm

Well, I made a thick gasket from some special heavy duty gasket material that we had at Brooklands. This alone was not thick enough so I added a standard gasket and some Hylomar. Now its all back it runs fine.

The other job was to remove and check the starter motor. Althought it never failed to start the engine it turned over very slowly. There was a lot of play on the shaft, and a circlip was broken, so I took it to Roy Auto electrics in Shepperton for a refurb. All is back in now and running much better.

This Tiger has proved to be my best ever classic car. Its bullet proof and reliable over the six years I have owned it.