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Discussion Starter · #1 · (Edited)
I have a '68 XR7 that I'm converting to factory power disc brakes, and from auto-trans to T5.
Years ago I pulled a power brake pedal out of a '68 automatic that looks like this:

http://images.cjponyparts.com/media.../9df78eab33525d08d6e5fb8d27136e95/p/d/pda.jpg

If I cut the pad size down will this work correctly alongside a clutch pedal?

I ask because when I look them up online it seems that the welded-on arch at the top is only on automatics. I assume this arch only acts as a return-stop for auto's since there's no clutch axle present to act as a stop, but wondering if I'll need to remove that as well?
 

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There is a difference from power and manual brakes, also 67/68. Check out mustang steve website, they have all that info listed with his conversion kits.
 

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Discussion Starter · #3 ·
Thanks. Yeah, I've been on there too, and I'm very familiar with the power/manual variants (I have the 5" pin to pinion spread for instance which is correct for my application), but the automatic/standard power brake pedal variations don't seem to be detailed there, unless I'm missing it.
 

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Yes, it will work correctly without removing that 'arch'. I recently converted from auto to T5 in my '69 with power brakes and simply had to cut material off the left side of my brake pedal to fit the new pedal pad. Everything else remains the same.
 

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Discussion Starter · #5 ·
Thanks guys. Also on Blue68cat's recommendation I revisited Mustang Steve's, it did at least confirm what that arch is for:

IMPORTANT:
On cars with manual brakes, the steel lever arm you see welded to the top of the pedal serves as a stop to keep the pedal from being able to travel back towards the driver far enough to pull the pushrod out of the master cylinder. If the rod comes out of the master cylinder, there will be no brakes.
Most master cylinders for manual brake cars have a positive rod retention clip built into the piston. The rod snaps in place and is very difficult to get out. MOST DISC BRAKE MASTER CYLINDERS DO NOT HAVE THAT FEATURE, since they were mostly designed for use with a power booster.
When swapping master cylinders and brake parts, BE SURE there is no way the rod can be pulled out of the master cylinder, by either a positive lever stop on top of the pedal, or by positive rod retention clip in the master cylinder, or both.
 
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