Astraea has a Henderson MK 5 manual bilge pump in the cockpit. It sucks water from the deepest part of the bilge and gets the final water from the bottom of the bilge that the other pumps leave behind. A few weeks ago while I was pumping the pump rocker arm assembly broke and I knew it was time to rebuild the pump.
I ended up buying 3 service kits to get all the right parts. The first was the rocker arm assembly, Whale part number AS0531. When I disassembled the pump I found that the diaphragm was in good condition, but the diaphragm plates that hold it were made of aluminum and had corroded badly and needed replaced. I ordered a new diaphragm plate kit and rebuild kit, Whale part numbers AS0561 and AK8050.
The rebuild was easy, just remove a few screws, clean everything up with a rag and reinstall. The whole rebuild took just a few hours and $160.52. I bought my parts from Downwind Marine online and they were delivered two days later.