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My Big Block '73 didn't come with power brakes. So, I decided to go with the Hydro Boost system.
Step 1) Remove master cylinder and factory pushrod from brake pedal. I got the clip off the brake pedal clevis pin, but there just isn't enough room to slide the pin all the way out. I guess this was probably engineered for safety reasons, but I'm stuck on step 1...
look above the pin, if its similar to trans am/Camaro you need to disconnect the spring and loosen the mount this gives a bit of free travel and the pin should come free its been 20 plus years so im fuzzy on specifics but I had a similarl issue with a customers pedal years ago when he wanted custom pedals installed I had work almost upside down
Many years ago, I had a brake job and had the master cylinder replaced. One day, some time thereafter, was doing a high-speed run at about 100mph and came up on a toll plaza in the distance. Went to hit the brakes and nothing. All the way to the floor. Started putting the car in lower gears until reached 2nd gear and then had to use the parking brake - which we all know if virtually worthless. Got to a stop about 50 feet from a car in front of me. Turns out, the clevis pin had fallen out. Now, reading this, I'll wager the shop did not do a good job of putting the pin in and it eventually worked loose. Same shop had to do it right! For free, of course. Was a scary event.
The pin hits the metal "Pedals Housing". I tried using a big screwdriver to pry the brake pedal to the side, but it only moves a little bit. I'm about ready to try to cut the pin in half, because the new HydroBoost came with another pin.
I think I would cut it. Does the new system hook to the same place on the brake pedal? From my 75 AIM It looks like power and manual brakes hook to different holes and use different striker plates. Power appears to use a lower hole than manual but the pedal appears to be the same. I would orient the pin backward to what it is now if possible or use a bolt with a nylock.
Good luck!
Can't recall how the brake lever pin is secured but the clutch pedal pin has 2 or 3 tiny spot welds. Mine failed on the clutch pedal and the clutch pedal dropped to the floor, that's how I know. You maybe fighting tiny spot welds on the brake pedal also.
Have you tried to push the pedal in and out? If you unhook the pedal spring it will be easier to move and it should be able to come forward or backwards enough to clear.
Have you tried to push the pedal in and out? If you unhook the pedal spring it will be easier to move and it should be able to come forward or backwards enough to clear.
The brake pedal pushes down pretty easily. I tried with the pedal in all different positions, plus while prying to the side with a long screwdriver. The pin is loose, but it just won't come out. I'm going to clamp a skinny pair of vice-grips on the pin head and then try to cut it with a Sawzall. That assumes I can get my fat head, a light, and a Sawzall all under the dash at the same time
The new brake clevis pin assembly is a completely different design that doesn't use the stock retaining clip on the end of the pin. I'll post a picture when I get it installed.
I don't think the brake pedal has more than one cross-hole for the master cylinder push rod to hook up to.
There should be two holes; one for the clevis pin and one for the striker bolt. When you switch from manual to power brakes, the striker is different and you switch holes.
Having said this, I’d go ahead and cut it. I’m moderately sure the pin was installed backwards. Since you have a new one, don’t sweat it.
The AIM shows the pin exactly as yours is. I bet they installed the pin and clevis before the pedal was installed in the housing. I can't see another way of doing it. That whole assembly would need to come out and that nasty little return spring on the lever would maybe be a nightmare to install.
Auto w/power has a bucket of clearance, can't explain the standard being that high up, seems like you shouldn't be the first to run into this. As you say, maybe the wrong pin
M
look above the pin, if its similar to trans am/Camaro you need to disconnect the spring and loosen the mount this gives a bit of free travel and the pin should come free its been 20 plus years so im fuzzy on specifics but I had a similarl issue with a customers pedal years ago when he wanted custom pedals installed I had work almost upside down
its a pita to get at but the design is actually intentional, that pin should never be able to come free on its own because if it did there would be zero brakes.
its a pita to get at but the design is actually intentional, that pin should never be able to come free on its own because if it did there would be zero brakes.
See my post where I lost the pin. Zero brakes at 100mph coming up on traffic. Mild panic, to put mildy.
In Mooser's photo the nut above the power clevis is where the non power clevis hooks. That appears to be where your your clevis is and where the interference happens. The power unit clevis is located lower down like Mooser shows.
My Big Block '73 didn't come with power brakes. So, I decided to go with the Hydro Boost system.
Step 1) Remove master cylinder and factory pushrod from brake pedal. I got the clip off the brake pedal clevis pin, but there just isn't enough room to slide the pin all the way out. I guess this was probably engineered for safety reasons, but I'm stuck on step 1...
Thanks,
John
I know this post is a year old but I’m having a hell of a time with this clevis pin also. I was wondering if you ever figured a ‘secret’? I have a manual brake 69 that I’m upgrading to hydrate hydro boost. I was able to get a small pry bar up there and push against the brake pedal enough to pull the old clevis pin out! Now I loosely installed the hard robots with the new clevis attached. The new pin is actually slightly longer so there is no way I could get it even close to getting in. I will attempt to old pin again tomorrow but was hoping someone had a ‘trick’ for this. If I could use the lower power brake hole it would be a breeze!! Unfortunately this hydro boost was for a manual car so it lines up with the top hole. Drilling a hole in the side of pedal housing would be a lot easier!!
There is a special place in hell for the engineers that designed that Clevis pin!!!! The only thing that got me through it was knowing everyone else had the same problem and eventually got it!!! My main problem was that my pin came in from the passenger side. I rebuilt the brake/clutch pedal assembly when I had the car apart and my AIM shows the pin going in from the passenger side. Big mistake. I was able to get the old pin out with a short pry bar and wiggling it. Spent hours trying to get the new one or old pin back in that way and it wasn’t going!!! The new pin is slightly longer but uses a cotter pin instead of that clip. Here’s how I did it for the next poor bastard that does this upgrade.
Thread the new horseshoe clevis on with 2-3 threads exposed on the inside. Install new hydro boost but leave all the nuts loose. Get under the dash and remove the brake light switch. The pedal should be up as high as it will go against the rubber bumper and clevis should be about lined up with the upper hole. Install the new clevis pin from the LEFT side (your right when you are lying on your back). It has just enough room under the nut for the brake switch bracket to get in the clevis hole. Wiggle the brake pedal a little while pushing row clevis pin and it slides in!!!! Now adjust the Clevis rod (another pain in the *** as I can only move the adjustment nut about 1/16 of a turn, flip the wrench, turn, and repeat a couple of times until my thumb cramps up horribly!!!). And tighten up the bolts on the hydro boost. Adjust so brake pedal is about 1/8-1/4” off the rubber bumper for fluid expansion when very hot.
11-19-2018, 01:41 PM
Help! I can't get the brake pedal clevis pin out!
