fhorta

To be exact , the measurement is 1 and 3/8 of an inch. The old one does seem to be one inch. If this new one was one inch, it be all good. The MC being deeper than usual and the booster rod being shorter than usual just messing me up.
just to be sure, the booster rod needs to backed in all the way before attempting to adjust the adjustable screw, right?

dmoe69

I'm not sure what you're asking, the booster rod is the adjustable screw. Once the jam nut is loose, the rod can be turned either in or out. I would be suspicious about that master cylinder. The rod can become separated from the diaphragm that pushes it. If that is what you are asking, then yes, the rod needs to be pushed all the way back until it is back in its (unseen) socket in the center of the diaphragm.

fhorta

Yes, that's what I was asking. Thanks. Looks like either a MC push rod adapter or booster rod extension kit , or another MC with less depth is solution. I don't really want to order another MC

dmoe69

When I had this problem upgrading my '66 mustang to power brakes, Scott Drake (the manufacturer/company of sale) volunteered to send me the "longer" booster rod. The one that came with their booster was short, like what you have. Fortunately, it was the same company sending me the replacement and it was a direct fit. Looking at the aftermarket rods, I don't see much information on rod diameter or thread pitch. I would be leery that any replacement you receive may not fit your booster.

fhorta

So the booster rod can be replaced? I have the one from old booster but didn't know they can be replaced. How do you do that without damaging booster. I don't care damaging old booster, but don't want to damage new one.

dmoe69

No, sorry for the misunderstanding, only the threaded end was replaced.

fhorta

So still at it. I bench bled, bled brake lines, was getting solid stream of brake fluid seen through clear plastic attached hose to bleeder valve. Got very decent pedal, but when started car, pedal soft again. In fact , brakes don't even engage. I have car jacked up so all four sides off the ground. The rear drums turn freely with no resistance when I put in gear. Any thoughts on this? I even adjusted brakes very close to the drums to where there is some resistance when sliding in drum. Also, I got the tool to get proper distance with master cylinder and booster push rod. I even measured with gauge so I think that part is good. I ended up making a kit from hardware store to get additional length.

I will add that I checked all sides for any leaks at the bleeder ports, brake lines, and the wheel cylinders. The only thing susspect of leak was front passenger side hydraulic line. Seems it needed a little snug. Once I did that, no signs of fluid there anymore.

I did also isolate the rear brakes by putting the plastic plug into the front brakes' port on MC. So now with car off, I get half pedal. But with car on, no pedal again. My plan is to leave like that to keep back brakes isolated and try bleeding process again. Thoughts, comments, ideas, suggestions appreciated. Maybe I should start whole process over again; bench bleed MC again, etc..?