Thanks for responding. '55-'58 dual action pump is the listing. No, no factory service manual. I am using this pump for a 'custom' application.
In your fist exploded view up there, that part # 9418. On both sides of the pump housing,,,,, I'm guessing, on each side of the arm pin # 9378, looks like a ball bearing seated into the pump housing.
I have gently tapped with a punch and hammer, either side and nothing moves.
That little 'ball' has to come out first to access the pin. I can not figure out how to remove either one of those little retainer balls.
I have GOOGLED and You Tubed in every wording possible, disassembly, assembly, rebuild, etc, spent hours looking at every video on the subject. Only ONE video showed a pump with those little ball bearings, but did not cover how to remove them!
Hate to destroy a good pump housing to find out what holds those little balls in place! Somebody on here has tackled the removable.
thanks