Full use of braking range; brake pedal height adjustment - 3000GT/Stealth International Message Center

ProwlerGT · 08-25-2007, 04:28 AM

BRAKE configuration = FWD ATX

Ok I'm pretty pissed off. I have been waiting months to install a new brake booster because I could not get my old one (with adjusting the push rod) to bring the brake pedal to spec height from the FLOOR of the car to the TOP of the brake pedal as defined in the manual which is 7.0 - 7.2 INCHES high. I have just installed the new/used booster (the other one was broken anyway; made a popping sound when I pressed the brake pedal) and I have performed the procedure in the manual and even had my sister read it to me slowly as I was under there looking at it to make sure I understood the words and my eyes corresponded. lol

Could a few of you go measure the distance from the floor (without the floor mat) straight up to the top of the brake pedal and tell me what you come up with please? Please make sure your measuring stick is STRAIGHT from the floor to the top center of the brake pedal as shown below in the diagram. I figure if I can get a few of you to do this it will help me with my theory that possibly the service manual is incorrect.

For those that do not know here is how it goes:

Brake stop light switch > small mounting plate > touches brake pedal arm > cotter pin connects to > brake booster push rod

The manual says to loosen the nuts for the brake stop light switch and the brake booster push rod and then to adjust the push rod in the respective direction in order to adjust the pedal level height. Well here is the damn thing... I have adjusted the push rod as FAR as it will go (JUST LIKE I DID USING MY OLD DAMN BOOSTER) without the push rod bolt starting to unscrew from the bracket that attaches to the cotter pin.

I have adjusted the brake stop light switch (it turns in its place) as far back as it could go (as far back = as high up as I could get it to allow the pedal to go to reach a 7.0 inch height) and so now having adjusted the push rod out as far as it can go it barely misses meeting up with the brake stop light switch by about 1/4 - 1/2 inch. I stop and measure the pedal height in this configuration and even with the push rod having pushed the pedal as far up as it can go I'm still at 6.0 MOTHER FUCKING INCHES !!!!!! AHHHHHHHHHHH !!!

This is why I'm doubting the manual because I have a known good brake booster and I know that I NEVER hear people talking on the boards about making adjustments to brake pedal height anyway. Am I on a wild goose chase or what?

Does the thickness of the brake pedal plastic/rubber itself over time decrease a whole INCH? Is this throwing off my measurement?

Did I BEND the brake pedal ARM by pushing the brakes too hard one day? I find it highly unlikely this would be the case, but I'm entertaining everything here.

Is the brake stop light switch supposed to push more so on the brake pedal arm than it does now? Its got like a spring loaded switch in it.

Is the brake pedal return spring supposed to provide some INSANE recoil and PULL the pedal back up very hard-tense like?

I don't like having the push rod turned to the edge/end of the rod/bolt inside the bracket that holds the cotter pin, but again this is the only way I can even achieve 6 inches of brake pedal height. Should I be adjusting the pedal height AFTER the system is all back, hooked up, and installed again? I'm currently trying to set the height while the booster vac line, MC and brake lines are disconnected.

ProwlerGT · 08-25-2007, 08:55 AM

I'm running a theory here that the TT and NA versions of our cars have different brake pedal heights for the reason that I know there are differently sized brake booster's on our platform. I believe I have the smallest one and I'm going with the idea that the smaller booster should have a lower break pedal height simply because I cannot adjust the height to be taller than about 6 inches whereas the manual states it must be 7.

For my FWD ATX 1995 NA it is physically impossible with what comes with the car to adjust the break pedal to 7" high from the floorboard UNLESS the ORIGINAL booster and the new/used one I put in were BOTH worn down by exactly 1 INCH each.

It would seem to make sense to me in the TT you'd have a bigger booster and slightly higher brake pedal height for longer braking stroke.

What ya'll think? Is ANYONE going to chime in here cause this is driving me nuts and I believe we need to solve this cause if the service manual has left out this tid bit then it needs to be known.

stfuad · 08-25-2007, 11:53 AM

I can measure it on monday when I see my car again. Unless someone else does it.

ProwlerGT · 08-25-2007, 03:31 PM

Quote:

Originally Posted by stfuad

I can measure it on monday when I see my car again. Unless someone else does it.

I'd really appreciate that and if I could get at least 2 other people to do that too then I'd feel pretty confident that whatever number comes from it is the right one which I'm guessing will not be 7" from the floorboard. I think its gonna come up to be like 5.5" or between that and 6".

THANKS !

ProwlerGT · 08-26-2007, 05:03 AM

Quote:

Originally Posted by stfuad

I can measure it on monday when I see my car again. Unless someone else does it.

Doesn't look like anyone else is gonna do it or cares so I hope you don't forget this Monday. I think this is a serious issue, but apparently others don't seem to or just don't have this problem.

Konfyoused · 08-26-2007, 06:47 AM

I'll be going out to finish putting the intake back on my car in a bit, so i can measure mine for ya.

Konfyoused · 08-26-2007, 03:30 PM

It's raining here right now, so i didnt get real indepth with it since i have no garage to work in, but it looks like, approx. 6 inches from the floor to the backside of the bottom of the brake pedal for me, mines a 1991 base model stealth mtx.

ProwlerGT · 08-26-2007, 05:58 PM

6 inches sounds about right although the diagram shows you to measure to the top of the brake pedal - even still its within or at 6 inches. I really appreciate it Konfyoused. Now if stfuad measures his tomorrow we'll have a possible pattern.

JASOG · 08-26-2007, 07:38 PM

I get about 5.5 inches. It's a 93SL. I would maybe get 7 if I pulled the carpet down, but I'm not gonna try that.

ProwlerGT · 08-26-2007, 10:09 PM

Quote:

Originally Posted by JASOG

I get about 5.5 inches. It's a 93SL. I would maybe get 7 if I pulled the carpet down, but I'm not gonna try that.

I don't think the carpet would add more than .5 inch. I bet it is a 6 too like myself and Konfyoused came up with.

INTERESTING THOUGH - Does anyone interpret the instructions of: "Turn off the carpet etc. at under the brake pedal" as meaning the actual CARPET underneath the FLOOR MAT? I've been interpreting this the whole time as it meaning the floor mat and not the actual carpet of the car.

It doesn't look like its that hard to turn the carpet back under there and I have it in my garage so I'm gonna remeasure where I have the pedal adjusted right now.

08-25-2007, 08:55 AM	#2 (permalink)
ProwlerGT King Detail Join Date: Oct 2003 Location: New Orleans area Drives: 95 3000GT Base DOHC Trader Rating: (11)	Re: Full use of braking range; brake pedal height adjustment I'm running a theory here that the TT and NA versions of our cars have different brake pedal heights for the reason that I know there are differently sized brake booster's on our platform. I believe I have the smallest one and I'm going with the idea that the smaller booster should have a lower break pedal height simply because I cannot adjust the height to be taller than about 6 inches whereas the manual states it must be 7. For my FWD ATX 1995 NA it is physically impossible with what comes with the car to adjust the break pedal to 7" high from the floorboard UNLESS the ORIGINAL booster and the new/used one I put in were BOTH worn down by exactly 1 INCH each. It would seem to make sense to me in the TT you'd have a bigger booster and slightly higher brake pedal height for longer braking stroke. What ya'll think? Is ANYONE going to chime in here cause this is driving me nuts and I believe we need to solve this cause if the service manual has left out this tid bit then it needs to be known.

08-25-2007, 11:53 AM	#3 (permalink)
stfuad Kirby... Join Date: Dec 2004 Location: Syracuse, NY Trader Rating: (12)	Re: Full use of braking range; brake pedal height adjustment I can measure it on monday when I see my car again. Unless someone else does it.

08-26-2007, 06:47 AM	#6 (permalink)
Konfyoused SOHC Abuser Join Date: Jul 2007 Location: Winder, Ga Drives: 1991 Stealth base Trader Rating: (1)	Re: Full use of braking range; brake pedal height adjustment I'll be going out to finish putting the intake back on my car in a bit, so i can measure mine for ya. __________________ I really need to put something here, don't I??

08-26-2007, 03:30 PM	#7 (permalink)
Konfyoused SOHC Abuser Join Date: Jul 2007 Location: Winder, Ga Drives: 1991 Stealth base Trader Rating: (1)	Re: Full use of braking range; brake pedal height adjustment It's raining here right now, so i didnt get real indepth with it since i have no garage to work in, but it looks like, approx. 6 inches from the floor to the backside of the bottom of the brake pedal for me, mines a 1991 base model stealth mtx.

08-26-2007, 05:58 PM	#8 (permalink)
ProwlerGT King Detail Join Date: Oct 2003 Location: New Orleans area Drives: 95 3000GT Base DOHC Trader Rating: (11)	Re: Full use of braking range; brake pedal height adjustment 6 inches sounds about right although the diagram shows you to measure to the top of the brake pedal - even still its within or at 6 inches. I really appreciate it Konfyoused. Now if stfuad measures his tomorrow we'll have a possible pattern.

Sponsored Links
3000GT/Stealth International Message Center Advertisement

08-26-2007, 07:38 PM	#9 (permalink)
JASOG Forum Member Join Date: Jun 2007 Location: Belleville, Illinois Drives: 1993 3000GT SL Trader Rating: (1)	Re: Full use of braking range; brake pedal height adjustment I get about 5.5 inches. It's a 93SL. I would maybe get 7 if I pulled the carpet down, but I'm not gonna try that.