Re:Water pump

[John Denson <john.denson@domain.elided>]

Mike,

Here's my ha'penny worth.

I have not had to rebuild a stag waterpump (thank goodness)
but I have rebuilt two pumps on two different Dolomites.
Given that I believe the pump is similar on the Stag and that both my
rebuilds lasted OK I'd suggest that rebuilding should be your first choice
- its certainly the cheapest, and you can control the quality.

As I said my only experience is on the Dolomite so please allow some
latitude if there are significant differences that I have missed (I dont
have a Stag manual to hand where I am currently residing):
Attempt to extract the pump as per the manual.
Rimmers web site for the Dolomite recommends using a slide hammer
but I used a large screwdriver set down in the radius of one of the fins
and patted the 'driver with the palm of my hand. That was all that was
required. I pushed the impeller off the shaft using a press. You could
improvise given a large enough vice but leave the hammer in your toolbox.
Get a machinist to face up the back of the impeller (making sure he has it
square in the chuck with a dial gauge) and removing as little material as
possible. I actually left slight pitting in the last one rather that go too
far. When pressing the impeller back on I found it necessary to (very)
lightly dot punch the shaft as both impellers by this time seemed on the
loose side.

Obviously use new seals everywhere.

And now to the point of all this. Both times I did this I was very careful
to set the clearance on the cover to the minimum tolerance and I believe
(it could be my imagination) that both cars ran slightly cooler. I know the
thermostat is supposed to compensate but it cant if its permanently
open.... This is not scientific I know but logically it would improve the
efficiency of the pump albeit perhaps only slightly. Anybody on the list
had this experience?

John Denson

john.denson@domain.elided
White '77 Stag