Water Pump - To Change or Not ?

[Stag74]

Whilst underway to replacing my mk2 Stag's damaged inlet manifold and doing a carbs rebuild, now the water pump is nicely exposed and potentially easy to work on.

Is it the considered right thing to do to fit a new water pump whilst access is available or is it best to leave well alone? I wasn't aware of any pump issues prior to strip down.

Thanks

[mike@thenook]

If you've got the inlet manifold off I would certainly take a look at it - careful with buying new ones though as there a lot out there 'made from butter' and will not last long - if the shaft and gear on yours looks good I'd just get a re- build kit and diy or if not too confident let Tony Hart or Robsport have it to recondition.
LD do a good upgrade kit which replaces the normal seal with a ceramic one, to fit this you have to have the impeller machined by LD's guys. Probably worth it in the long run.

Cheers

[flying farmer]

Difficult one this, the pump could be perfectly ok for thousands of miles if left alone, or it could fail catastrophically within a few miles wrecking your engine in the process!

As a compromise you could remove the pump cover and check the impeller for backlash, if the gear teeth are good there should only be a few degrees, then just refit the cover with the correct thickness gaskets.
If there is significant backlash the teeth could be on their way out and pump removal for inspection would be a very good idea,but the odds are the jackshaft would also be knackered.
Sometimes you can be lucky and the pump will come out with the cage attached, in which case it can simply be refitted with new O rings if it looks ok.

If the cage stays in the block then the pump will have to be stripped to refit the oil seal, rebuild kits are cheap but sometimes the pumps leak water after a rebuild unless the impeller is skimmed flat.
If you do decide to remove the pump, don't buy a new one until you have seen the gear teeth condition. If the jackshaft teeth are worn fitting a new pump will not help, and might even hasten the engines demise as the teeth will not mesh correctly. Personally if the jackshaft teeth are on their way out I would spend my money on an electric pump conversion instead as it saves having to strip the engine to change the jackshaft.
I have personally had two water pump/ jackshaft teeth failures. The first was on a Dolomite Sprint engine (same water pump). I caught this one just before the teeth stripped completely and fitted an electric pump.
The second one was on my 1st Stag 3 months after I bought it. This resulted in a seized jackshaft, broken timing chains, bent valves and a total engine rebuild, so I tend to be very wary of water pumps!
Neil

[Stag74]

Catch 22 I guess. Will speak to the suppliers you mentioned tomorrow to get their thoughts too.

What started out as just a wrong fuel pump when I bought the car then became leaking carbs, broken and leaking inlet manifold, and just tonight discovered dizzy pedestal bolt fixing flange broken off on one side.

So with that track record, best I check the pump.

Roy

[mike@thenook]

Out of interest, who did you buy this car from? Any chance of recourse for what appears to be perhaps a lack of honesty on the part of the seller?
All fixable I know but......

[Goldstar]

Inlet manifold cavalry on the way.....

If the jackshaft is good and you are fitting a new water pump, speak to Stuart at SOC spares.

[flying farmer]

Wouldn't bother too much a bout the broken flange on the dizzy, one side holds it just fine, just don't get too enthusiastic tightening it up or you will break the remaining one!
Neil

[Stag74]

Out of interest, who did you buy this car from? Any chance of recourse for what appears to be perhaps a lack of honesty on the part of the seller?
All fixable I know but......

No recourse, was bought privately at a fair price both ways. But i was told engine had recently been fully rebuilt which it clearly was not. Knew there may be some risk involved but for an mot'd car, it's more than I bargained for.

[Stag74]

Will speak to Stuart at soc as well.

Have decided to make an L-shaped clamp washer for the dizzy broken side. That should work ok. And yes, will be very mindful of over tightening.

[mike@thenook]

Stuart is a great guy, used to buy loads of parts from him years back - always helpful and never expensive

[Mark Serj]

I had never even seen a Stag water pump (or any other car make come to think of it - just bikes) until I took mine out due to it leaking. I got a rebuild kit from LD and I machined the impellor to fit the ceramic insert. This is a straight forward job as regards the machining / seal fitment but LD don't charge too much to do it anyway. As regards the pump rebuild, it's quite straightforward providing you:

1. Read well up on it first
2. Make sure you use suitable tools to press out / extract and press the bearings / seals back in
3. Take your time and check, check and check as you go.

If you aren't too confident, get TH or LD to do it all for you