63 Brake Pedal Height

[Joseph S.]

Had a vacuum leak from the booster on my J-50 equipped, survivor, 63 L-75 Coupe. Had the booster rebuilt by Booster Dewey in Oregon and after installation I seem to have a lower brake pedal height (no I did not take initial measurements) than before the booster was originally removed. I have had to adjust the brake light switch in .5" which supports my impression that the pedal is lower.
Service Manual specifies brake pedal to be 4 5/8" above carpet. Mine is about 4.5" so very close to spec.
However this leaves a 2" difference between the level of the clutch and brake pedals. My 63 roadster with standard brakes has brake and clutch pedals on nearly the same plane.
I have inspected and the booster sits flush with the firewall. In addition, I have adjusted the brake booster rod clevis all the way out to achieve the highest pedal. Have talked to Dewey and he assures me he used my original parts & commented this was an issue with J-50 cars that year. Still a height differential of 2" between clutch and brake pedals seems excessive.
Is this as configured? Are other J-50 cars similarly configured?

[Timothy B.]

Re: 63 Brake Pedal Height

Joseph,

If the pedal was a different height before the overhaul than look at what changed. Certainly not anything in the master cylinder (same part), my thoughts are the parts used in the overhauled booster, very frustrating.

Hopefully others with 63 power brakes will read this, I could be wrong but my memory is telling me the rod going into the master cylinder is adjustable on the 63 booster.

[Frank D.]

Re: 63 Brake Pedal Height

I'm assuming you already know the brake pedal clevis goes in the bottom hole on the pedal downrod on power brake cars...
I had the same issue as you when my booster was rebuilt by Karp's Power Brake Service and they also stated they painstakingly used OEM or original parts - pedal height was disconcertingly low and the pedal travel, when depressed, was alarmingly low off the floorboard.

My 63 rod between the booster and M/C is adjustable, but you have to be EXTREMELY careful with it (actually don't screw with it at all if you can avoid it). At any rate the tip of that rod can be screwed in or out but is VERY sensitive....a minute amount at a time is best. If you go too much your brakes can drag....so its adjust a bit, test a bit, adjust a bit more. When all done you should still be able to push the car by hand with parking brake off in neutral. Then drive enough to get the brakes good and hot and, again, you should be able to roll the car; it should drift backwards on a hill at a stoplight with your foot off the brake.

This still didn't satisfy me so I ordered a different pedal clevis/push rod from McMaster's and installed it to get the brake/clutch pedals nearly even. Having said all that the 63 shop manual states the power brake pedal is good if, when fully depressed, it is 1" or more off the floor board. That's scary as heck to me and the new pedal push rod increased that at least another inch - prob a bit more. MUCH more confident stopping.
The pedals are nearly even too.

You may or may not want to do that to a survivor car...but I drive mine and wanted it to stop with more conviction than stock...others have used the aftermarket clevis on 63s and have had the same success that I have..

[Bob W.]

Re: 63 Brake Pedal Height

Joseph

At the top of this page go to advaneced search and type in 1963 p/b booster to pedal adjustment. There is some info there.

Bob

[Joe R.]

Re: 63 Brake Pedal Height

I'm not sure what differences there are between '63 and '67, but for '67 I determined that it was *normal* for the brake pedal to sit lower for cars equipped with power brakes than cars with manual brakes. The difference is related to the different pick-up point on the brake pedal for power brakes versus manual brakes.

While GM appears to have considered this to be okay, it bothered me when I converted my '67 to power brakes. Even with the pushrod adjusted to maximum length, the brake pedal sat about an inch below the clutch pedal and went very close to the floor when the brakes were applied. It just didn't feel right to me.

So, I substituted a longer clevis to raise the brake pedal and make it even with the clutch pedal. I'm pretty sure this is not "correct" for originality, but it sure feels better for everyday driving. The clevis I used was purchased from McMaster, but I'm away from home and don't have the part number. I can dig it out and post it on Sunday if you like.

[Frank D.]

Re: 63 Brake Pedal Height

I'm not sure what differences there are between '63 and '67, but for '67 I determined that it was *normal* for the brake pedal to sit lower for cars equipped with power brakes than cars with manual brakes. The difference is related to the different pick-up point on the brake pedal for power brakes versus manual brakes.

While GM appears to have considered this to be okay, it bothered me when I converted my '67 to power brakes. Even with the pushrod adjusted to maximum length, the brake pedal sat about an inch below the clutch pedal and went very close to the floor when the brakes were applied. It just didn't feel right to me.

So, I substituted a longer clevis to raise the brake pedal and make it even with the clutch pedal. I'm pretty sure this is not "correct" for originality, but it sure feels better for everyday driving. The clevis I used was purchased from McMaster, but I'm away from home and don't have the part number. I can dig it out and post it on Sunday if you like.

Exactly the situation I encountered, and, the solution I used to make it acceptable to me:

McMasters part number: 6071K14

I did cut about 1/2" off the new clevis to achieve the "perfect" pedal height (for me)...

[Bob W.]

Re: 63 Brake Pedal Height

Joe / Frank

Does McMasters have aweb site if so can you posted so i can order one for my 63. Thanks

Bob

[Frank D.]

Re: 63 Brake Pedal Height

My car was regionally judged with the McMaster part - I'd have to look to see if there was any point 'hit'...but I don't care...with that piece I don't even think about my brakes anymore instead of having that millisecond of panic when the power brakes got near the floorboard when stopping.

This is their web page for clevis rods...the part number I've given above is on there :

https://www.mcmaster.com/#catalog/123/1258/=170qalp

[Bob W.]

Re: 63 Brake Pedal Height

Frank Thanks for posting Mcmasters site.

Bob

[Joe R.]

Re: 63 Brake Pedal Height

Joe / Frank

Does McMasters have aweb site if so can you posted so i can order one for my 63. Thanks

Bob

I checked my records and the McMaster part that I used was the 6071K14:

https://www.mcmaster.com/#6071k14/=1712mm7