Help with brake pedal please

[wareaglescott]

I installed my pedal box yesterday. I cant seem to get the brake pedal adjusted to stop hitting the frame rail.

And I cant tell how much the frame is restricting the movement. I am not sure if I just don't know how to adjust it or if my heat shield is causing the problem. I put the heat shield on the back of the piece the pedal box attaches to and it is in between the pedal box and the frame. It is bolted down and very thin. I cant tell if just the minimal added thickness is causing the issue.


Now in this picture you are seeing the heat shield on the back of the Fpanel. That is cut around the other area and not the issue. What I am trying to show in this picture is how tight the black pedal box piece is sandwiched up to the other black frame piece it mounts to. Hard to tell from the picture but the thickness of the heat shield causing the pedal box to sit possibly further aft than if it where not there cant be more than 1-2mm.


I have messed with the threaded rods from the master cylinders quite a bit. If I want the pedal to move away from the frame do I need to screw them into the receiving piece more or back them out?
I feel like I am totally missing something here in the adjustability. Any suggestions are appreciated.

[boat737]

Have you put in your brake light switch yet? That will, after adjusting, keep the pedal off of the 3/4 inch cross bar. Is the pedal at about the right position with the pedal arm touching or just off of the cross bar? I wouldn't think a few thousands of an inch would make that big of difference in where the brake pedal is positioned. (I could be wrong though, it's been known to happen.)

Also, you will probably run into the clutch interference on the angled 3/4 inch bar as well. Search the forums for different fix's on that. (Here's mine from a couple months ago http://thefactoryfiveforum.com/showt...terference-Fix )

[Courtnie Provencher]

The brake pedal can hit the 3/4" tubing, and not be a problem. Our rolling chassis is set up just like that. Unfortunately, you're not going to know if you need more adjustment out of the masters until you drive the car and see what how the brakes feel.

[wareaglescott]

Ok thanks Courtnie.

[silver_pilate]

Screwing the pushrods into the clevises will pull the brake pedal off of the frame tube. A small change in the pushrod depth in the celvises will have a large effect on pedal position. I have my balance bar set to be level with no pre-load, and my brake pedal just clears the 3/4 tube and activates the brake switch. I'll adjust once up and running.

--Nathan

[wareaglescott]

Screwing the pushrods into the clevises will pull the brake pedal off of the frame tube. A small change in the pushrod depth in the celvises will have a large effect on pedal position. I have my balance bar set to be level with no pre-load, and my brake pedal just clears the 3/4 tube and activates the brake switch. I'll adjust once up and running.

--Nathan

Thanks Nathan. I was having trouble telling exactly which way was doing what so this is helpful.

[boat737]

Screwing the pushrods into the clevises will pull the brake pedal off of the frame tube. A small change in the pushrod depth in the celvises will have a large effect on pedal position. I have my balance bar set to be level with no pre-load, and my brake pedal just clears the 3/4 tube and activates the brake switch. I'll adjust once up and running.

--Nathan

According to Wilwood, you start by screwing in the Front M/C rod 4 turns into the clevis, and the Rear, 7 to 8 turns into it's clevis. When I started that way, both rods were slightly pushed into the M/C's with the pedal against the brake light switch/stop. so I turned both rods equal turns into the clevis's (keeping the 4 turn difference between them) until the brake pedal had some play in it and the M/C pistons/rods were fully extended. It took about 4 more turns each.

BTW, Wilwood also says to start with the balance bar exactly centered in the brake pedal, with about .1 inch clearance on each side to the clevis's (a total of .2 to .25 inch total clearance. It seems excessive, but that way both M/C rods will be parallel to each other. Wilwood is adament about that clearance.) And if you need to move the balance bar for brake bias, only move it a few turns at most.

[wareaglescott]

According to Wilwood, you start by screwing in the Front M/C rod 4 turns into the clevis, and the Rear, 7 to 8 turns into it's clevis. When I started that way, both rods were slightly pushed into the M/C's with the pedal against the brake light switch/stop. so I turned both rods equal turns into the clevis's (keeping the 4 turn difference between them) until the brake pedal had some play in it and the M/C pistons/rods were fully extended. It took about 4 more turns each.

BTW, Wilwood also says to start with the balance bar exactly centered in the brake pedal, with about .1 inch clearance on each side to the clevis's (a total of .2 to .25 inch total clearance. It seems excessive, but that way both M/C rods will be parallel to each other. Wilwood is adament about that clearance.) And if you need to move the balance bar for brake bias, only move it a few turns at most.

I had to thread both mine in about as far as they could go to get the brake pedal off the frame. Now I don't have the lines run or any fluid in the system yet. Will that make a difference? Should I be concerned it took so much thread just to get it off the frame.

[boat737]

I had to thread both mine in about as far as they could go to get the brake pedal off the frame. Now I don't have the lines run or any fluid in the system yet. Will that make a difference? Should I be concerned it took so much thread just to get it off the frame.

It does seem somewhat out of the range of reasonableness, and I doubt loading, priming, bleeding the system will make any difference. You can tell if the M/C pistons are fully extended, since they have an internal spring. Just push them in a bit, and they will return out to their limit (a spring clip holds them in.) Is the brake pedal located in about the correct position in the footbox? It should be near the clutch, maybe just a tad forward/down of it, and rearward of the throttle pedal.

[wareaglescott]

It does seem somewhat out of the range of reasonableness, and I doubt loading, priming, bleeding the system will make any difference. You can tell if the M/C pistons are fully extended, since they have an internal spring. Just push them in a bit, and they will return out to their limit (a spring clip holds them in.) Is the brake pedal located in about the correct position in the footbox? It should be near the clutch, maybe just a tad forward/down of it, and rearward of the throttle pedal.

Brake pedal looks to be in correct position best I can tell. Don't have my clutch master cylinder yet so the pedal is hanging freely. Don't have my Coyote motor so I have not done the accelerator pedal yet. My seats are on backorder so I cant really put one in to sit in and see how the pedal position feels! Eyeballing it in an empty space with no frame of reference it looks pretty good though! haha
Thanks for the feedback.

[boat737]

I'm out of town at the moment, so I can't get a measurement on mine. Are there any folks out there than can take a measurement on where the brake pedal sits? Say from the forward wall of the footbox, or back from the step in the floor?

[karlos]

None of these photos are very good but hopefully they help a bit. Every installation will of course be different, but my pedal is very close to the frame tube as well (first two photos). When I installed the master cylinders I adjusted the thread engagement on the clevises so that I had about 1/16" clearance between the pedal and the frame after making sure the MC pistons were fully retracted. I then adjusted the brake light switch so that it was fully depressed with the pedal in that position.

The last photo shows that the center of the pedal is right at 11" measured to the front of the footbox. I placed the ruler so that it rested on the round frame tube and just touched the front of the footbox.

[edwardb]

Mine looks very similar to the pictures posted by Karlos. The brake pedal arm looks to be 1/8-inch or less away from the frame. I also show about 11-inches measured the way Karlos shows. I also agree with his explanation of how to adjust. Make sure the MC is all the way out against the stop and turn the pushrod in the clevis to get the pedal at the proper location. Then adjust the brake light switch. Note also with the 1-inch MC and 7/8-inch slave I described in my build thread for a hydraulic setup, the clutch pedal will adjust to the exact height as the brake pedal and give perfect clutch actuation. Note this is different than the standard 1-1/8 inch MC that Forte typically supplies. I had that size installed initially, and the effort was a bit heavy plus moved the slave too much.

[Jacob McCrea]

For what it's worth, it might be good to fabricate an adjustable pedal stop, so that the clutch pedal bottoms out on the stop before impacting the 1" frame tube. It looks like you could bolt or weld a stop to one of the two square tubes down there. I can post an example of what I did for my coupe if you want.

[boat737]

I forgot I had this . Balance bar adjustment.

http://www.wilwood.com/PDF/DataSheets/ds252.pdf

http://www.wilwood.com/TechTip/TechPedalTip.aspx

http://www.wilwood.com/TechTip/TechCaliperTip.aspx

[wareaglescott]

Thanks for the replies. I have been out of town for a few days. Plan to look at the measurements and other info today or tomorrow.