I just rebuilt two pumps for my 51 Frazer Manhattan. The only trick is to make sure the diaphragms are flat when securing the top and bottom housings. The springs push the diaphragms away from the main housing and if you tighten the screws that secure the top and bottom housings to the main housing without leveling the diaphragms, you will loose most of the stroke from the arm. The only tool you need is to space the pump arm in a position to keep the diaphragms flat or level to the housing. It's listed as KF-65 flexing tool. I used a piece of weld rod bent in a 90 degree angle and placed it against the arm and housing. To install the seals, I used the back of a socket and a punch to stake them secure into the housing. The diaphragms actually hook quite easily onto the arm and lock in position. They are harder to release than to install.
