Brake and Clutch Pedal Height Discrepancy

[taguy16]

I converted my '73 Road Runner to a manual transmission and used a used pedal assembly what I was led to believe was for my car. Now with everything installed as per the Chrysler Plymouth factory shop manual the brake pedal is a good two inches lower than the clutch pedal where you press down with your foot. I'm wondering if this is normal because I've never seen this on any other car I've worked on, and it seems odd you would have to press the brake pedal down almost to the floor to stop the car. In case it matters the car has power brakes and I replaced the master cylinder at the time I did the conversion. I also installed a new clutch pedal bumper which determines how high the clutch pedal is off of the floor.

To fix this I've tried lengthening the adjustment on the pushrod that goes into the back of the master cylinder, but all that did was make it so that the piston in the MC started to compress when I forced it down on the brake booster with the nuts on the studs. The reason why the pedal is so low appears to be because the rod that connects the pedal arm to the pivot on the pedal box is so short. What length is the correct one so I know if mine is right or not, and were different lengths of these used for different years/applications? I'm thinking that maybe the pedal box assembly I got acquired the wrong one of these rods somewhere along the way.

Any insight into this would be much appreciated.

 

[Russ69Runner]

It sound's as if you did not get the rite one for your car. The pedals should have been even at the bottom. Sorry to say this. Just my thought's. Even the stroke on the brake pedal dose not sound rite. Russ.

 

[69hemibeep]

I don't know the cause but I have noticed that on several cars.

 

[taguy16]

I found this article that explains the differences and similarities between the Mopar pedal assemblies: https://www.hotrod.com/articles/mop...2_z-four_speed_pedals-1971_1974_b_body_pedals . The 71-74 B Body pedals in the picture in this article seem to line up better than mine. I still think that if there's a problem with my pedal assembly it's with the link connected to the pedal arm.

 

[Russ69Runner]

Cant say for sure but on the 69 runner the clutch and brake pedal all hang on the same pin with bearing's and bushing's. After looking at yours is it put together that way also.

 

[taguy16]

The problem is that the master cylinder is so much higher than the brake pedal on the '71-74 b-body cars so Chrysler had to go with this complicated multi-link set-up to compress the piston instead of just a single pushrod like on most other cars where the MC is at about the same height as the top third of the brake pedal arm.

I still think finding a longer front brake pedal link or lengthening the one I have is what I'm going to have to do to get it to come up closer to the height of the clutch pedal and so I get a better pedal stroke.

 

[Russ69Runner]

Some times we have to do things to make it work. Good luck Buddy. Russ.

 

[69hemibeep]

I have a 73 e-body pedal with that gizmo on it, came off of a power brake car. Looks like it changes the geometry of the swing to the master.