My rod is too short.

[red211]

Swapping the 63 to a disc brake set up off an 87 donor truck. Not doing power at this time so swapped a dual bowl disc drum non power mast cyl from a 71 c10. Got it at OReilleys, it is the same as the impala and such. Bolted it on but rod is short, adjusted out but still short. The flange on the master cylinder that sticks through firewall is shorter than the single that was on it by a good inch. I went back and We did some checking but all were shorter. I made a spacer that fit inside plunger and that fixed it but haven't seen anyone else with this issue. I know the old master is correct since I have had it since 1980 and it was 100% original when I got it from Grandpa. Anyone else had this?

[shp4man]

Lol.

[studeclunker]

Originally Posted by shp4man

Lol.

Oh dear, me too, I fear!

You are doing disc brakes without a booster? My experience has been that disc brakes without power assist are a right good bugger to use. The disc brakes require a lot more leg pressure to work. The power booster makes it a lot more tolerable.

[nsb29]

Story of my life

[nsb29]

I did a 65 ford four wheel disc brakes stock master cylinder stopped very well no power buster

[red211]

I am not worried about performance, nothing wrong with non power, just takes more leg power. It just surprised Me that everything I have read it was supposed to be a bolt on with no modification and something many here have done without mentioning the rod length. My spacer worked perfect, I just thought it was odd no one had mentioned it.

[Captainfab]

This issue is because the '63-'70 master cylinders have a shallow bore in the back of the piston. The '71 and up masters have a deep bore in the back of the piston.

[studeclunker]

Originally Posted by Captainfab

This issue is because the '63-'70 master cylinders have a shallow bore in the back of the piston. The '71 and up masters have a deep bore in the back of the piston.

I have been considering replacing my little single pot with a dual. So, I'll keep that in mind. Cap'n do I have to replace the booster when changing over from a single to a dual?

[Captainfab]

No, not as long as you use a dual reservoir master with the deep bore in the back of the piston. A '67-'70 truck master will have that deep bore.

Originally Posted by studeclunker

I have been considering replacing my little single pot with a dual. So, I'll keep that in mind. Cap'n do I have to replace the booster when changing over from a single to a dual?

[69 C10 LWB]

I ran into the same issue with my 65 when I swapped to a dual master cylinder. I bought a 3/8 coupling nut and drilled it out and retapped it to the proper thread which I think is 7/16 fine thread and cut the head off a bolt and used that to extend the pushrod the extra inch I needed.