Another Master cyl question

[halfcockedcustoms]

I am finally switchin to a dual pot master(also puttin disc brakes on the front)..I've read up on the threads many times,,but I have made myself confused a lil...I am stickin with manual brakes and got a master for a 72 manual disc truck..This is where I am confused,,Do I need to extend the pushrod for this master? The bore size in the stock single and the new dual pot are the same size/depth...Can somebody please unconfuse me..Thanks

[slepysal]

For what it is was worth I had to extend mine about 1/2 inch.
Are you bolting the new directley to the fire wall or using an addaptor plate,that will make a diffrence. Is your push rod addjustable? If so then you can addjust it as needed, if yours is not then you will have to install and see if it has enough travel then get another one or moddify yours. Not hard , just a bit time consumming hope this helps

[Tx Firefighter]

I had to extend it too. The master cylinder came with a new one. I cut it and the original one and welded them together to get the right length.

[halfcockedcustoms]

Originally Posted by slepysal

For what it is was worth I had to extend mine about 1/2 inch.
Are you bolting the new directley to the fire wall or using an addaptor plate,that will make a diffrence. Is your push rod addjustable? If so then you can addjust it as needed, if yours is not then you will have to install and see if it has enough travel then get another one or moddify yours. Not hard , just a bit time consumming hope this helps

Its bolted to the firewall and it is adjustable,,thanks for the info...

[slepysal]

Originally Posted by halfcockedcustoms

Its bolted to the firewall and it is adjustable,,thanks for the info...

Then you should be good to go ! You should be able to use your old one, and chances are you wont need any addjustment!

[bubba327]

I always check for clearances when assembling, I use my kids modeling clay as a plasti-gauge.
I put a little ball of clay on the rod end ,then assemble and dis-assemble the master cylinder on the booster(or pedal rod) and check tolerances. I can either find a longer rod or machine a little bit off. An easy way to keep brakes from either dragging or that annoying distance in the pedal travel.
This works mainly on power booster applications , without the booster, you can feel the play in the pedal and adjust things under the dash as the other guys mentioned.