Yanmar water pump seals

[Topcat47]

I've got my wee pump off and in bits. Very easy so far. The trouble is I can't budge the old seals. I've tried a gentle approach, tried levering with a screwdriver, and sprayed the inside with release oil but they seem stuck. Even a hot air gun on the casting doesn't help. I don't have a press, although why one would be needed is beyond me. The workshop manual for the 1GM10 tells me how to strip and rebuild the rest of the engine but is quiet on the subject of the water pump. The seals are not huge and I'm reluctant to apply too much force and am wary of damaging the pump housing.

 

[rotrax]

Try drilling a 2mm hole in one near the edge. Then screw in a tightly fitting self tapper. Grip the self tapper with a small good quality mole grip and pull or use a block of wood to lever the seal out.

This always works for me.

 

[Topcat47]

After removing the shaft and bearings, that came out easily, I eventually laid it down on the bench, pump uppermost, and used a long needle punch, as advised by Marine Power. The lower seal came out quite readily, but the upper seal was still quite difficult to remove. How anyone would do this at sea is beyond me, but needs must, I suppose.

I assembled the seals on the shaft, then re-fitted the shaft after turning the body upside down. A squirt of GT85 was all that was needed to refit it.

I tried drilling into the old seals, once they were out. The seals are different sizes and I doubt it would be possible to drill into the larger and be sure of missing the pump body when the drill penetrates the seal, never mind hitting the smaller.