Water pump, here we go again ...

Returned from the Alps with an oil leak from the water pump. So in the previous weeks I removed the carburettors, manifold etcetera again, in order to rectify the problem. As I already have covered that not so long ago I won’t bore anyone with the details. With the pump cover removed I wanted to undo the impellers bolt, to fit a big washer, so I could lever the pump out easily. I needn’t have worried, at the first turn of the spanner the complete water pump assembly (including brass cage) came out. So no need to use this simple but effective puller again ...

With the pump out in one piece, the cause for the leak was easy to spot. The oil seal that should sit snugly on top of bearing, was completely visible through the holes in the brass cage. This means that one way or another the seal got dislodged from the brass cage, enabling oil to leak out. Either I didn’t fit the seal properly or there is something wrong with it.

As I only fitted this pump two weeks ago it hadn’t endured much in the way of use, making dismantling it rather straightforward. There was no visible damage to the seals so I reused both of them. Only this time I made double sure that the oil seal was properly pushed into place, with the water thrower tightly on top of it. Followed by the coolant seal and the impeller.

Having finished the pump, it was time to put everything back. Only little problem I encountered was the manifold + carburettors assembly. Before I fitted these I had glued the gasket and O-ring to the cylinder head’s mating face. But while fitting the manifold (with the carburettors fitted to it) I managed to dislodge the gasket. But I got it in place in the end. Only to find out, while refilling the coolant system, that there was a leak from the O-ring. Turned out that the supplied O-ring was to small, as a result of which it had moved inside the recess while I tried to reposition the gasket, causing the leak ...

As you can see the inside diameter is spot on, but comparing the original O-ring with the supplied one clearly shows the size difference ...

Should have done that before fitting the ring ! But it turned out that the supplied ring fits perfectly inside the original one. So to prevent this happening again I used both rings, glued in place with sealant ...

And with the manifold ready for refitting I had another go at removing the old gasket. Nothing difficult there, you only have to be careful not to drop bits of gasket into the inlet ports. And when it happens the air compressor is very useful indeed ...

After that is was a fairly long wait for the new gasket to arrive, which eventually arrived last Friday. So yesterday morning I started reassembling the manifold and carburettors. First I glued the gasket to the head with a little bit of sealant ...

After which I fitted the manifold. As I removed the carburettors from the manifold this was much easier, then the previous time. But I did use a few drifts, just to make sure the gasket couldn’t move too much ...

Also used a small 13mm socket with a flexible joint to fit the bolt that sits underneath the thermostat cover. As it is slightly oversize I didn’t tighten it up with this socket, but used a ring spanner with the correct size (½”).

And with the manifold in place ...

It was just a matter of transferring these parts from the boot to the engine bay ...

And take her out for a spin ...

Back home I found a little bit of oil underneath the water pump slot, and I had to tighten one of the radiator hoses slightly. Will see how that develops in the near future ...