by Dave Pritlove
Date Added: Friday 18 May, 2018
I had coolant leaking from the front of the engine, only discovered when my radiator burst and the temperature gauge went to maximum. I ordered a new water pump, radiator, thermostat and gasket and new belts (as only the alternator belt had been changed since I bought my Mk1 150,000 km ago). I'd inspected all hoses and they appeared ok.
Ordered early afternoon and that evening I sprayed as many nuts as I could access, with WD40 to help when coming to remove them. Next morning I checked the order tracking to find expected delivery was 1400-1500. On cue, the order arrived just as I was finishing parts removal and cleaning the old gasket off the water pump mount. Apart from half the screws retaining the plastic cover under the engine front breaking, everything came off OK.
Fitting the pump was a little fiddly but not difficult. It took quite a while to clean off all traces of the old gaskets and it was easy to miss bits so take time. Holding the new gasket, and the smaller side-entry gasket, in place was almost impossible and I eventually resorted to tacking them in place with vaseline - a practice which I believe is frowned upon but I judged it less risky than kinking the gaskets. I also gave up on the top rubber dust seal as I could find no way of keeping it in place. There was not one fitted to the pump I took off and I was worried a poorly fitted version might catch in the timing belt.
The new pump had a cast metal impeller, the one I took off was pressed stainless steel. The outer rotating plate onto which the pulley fits was a circular disk on the new pump, rather than the three-spoke hub on the old one and as shown on the picture for the new item. This made it impossible to secure one of the dust cover retaining bolts unless it was inserted part way into the cover before positioning the cover - easy to work out but worth a mention.
The hardest part of reassembly was accessing the two bolts holding the side-entry feed to seal the gasket. It was not possible to get a torque wrench on them so I tightened as evenly as possible with an open ended spanner. This was slow as only a small turn could be made each time due to access.
Incidentally, the removed pump spun freely and was probably perfectly ok to refit, there does not seem to be much to go wrong with them other than bearings. In most cases, I suspect, new gaskets are all that would be required but the work would be exactly the same.