The intake and outlet valves looked fine, the rubber diaphragm was a bit distorted but still pliable with no tears or holes. I adjusted the diaphragm and reassembled, but it's still not pumping.
A spares/rebuild kit consisting of rubber o-rings, valves and diaphragms is about $30 US, while a replacement Mk 3 from discounters is $100. I like saving money and don't mind the work, but I wonder if the rebuild will do the trick or if I should save the trouble and splurge on a new one.
The deformed diaphram and perhaps one of the other seals is likely sucking air. I have rebuilt both the galley and the head pumps with mixed results. The first one I did was great, however the second one leaked for some unknown reason and I could not get it to stop and ended up finding a replacement at a used gear chandlery. During the rebuild, it was pretty tricky to get everything to line up with the spring in the middle of the body trying to push everything apart. Since I am pretty thrifty, if I had to, I would try the rebuild again.
