I checked the plunger going into the master cylinder and tightened it up about 5/16 inch so there was no pedal play. Still can not get it to pump up. Finally opened a bleeder valve and stuck a hose on it, then pumped master cylinder twice. Not much fluid coming out and had bled that cylinder before. I think I have another bad master cylinder. The bore on this master cylinder is 1 inch and 3/4 ton pickups of that year had a master cylinder with a 1.125 inch bore. Looks like about all else is the same, so I may just go with the bigger bore MC. Is there another test for the master cylinder that I could try? Never had this much trouble with brakes on any vehicle ever before and have been turning wrenches for over 55 years.
Any thought on going with a bigger bore Master Cylinder? Cardon and Fenco both show 10-1331 part numbers.
