The Stovebolt Site Forums The Shop Area Driveline Clutch/brake pedals pivot rebuild AD?

I'm planning to rebuild the pivot area for the brake and clutch pedals on my advanced design era truck. Mine is badly worn and the pedal arms drag on the floor when pushed in. I was hoping to see a tech article on doing this rebuild, but didn't see anything. Looks challenging. Anyone done this? Advice?

I don't have an AD but it does not look challenging to me. It's one of those take it apart and see what it needs. Round bushings/tubes rotating on a round rod or tube is what I assume. If it's too far gone or out of your fabbing skills, maybe buy a donor..........OR
HERE is some of what you need.

Also maybe: click and click

Good chance for you to do a tip. Do what a professional photographer does, take many many pics, then choose the best for the tip.

There could be a few reasons the pedal arms are dragging on the floor. Most common I think is they're out of adjustment (although this doesn't need to be done often). Each pedal is a two-piece affair and can be adjusted with a 5/8" wrench (outside the firewall...engine side). You'll see how the clutch and brake pedal rods connect with the swinging arms and it is all pretty self-explanatory. If your bushings are worn, they can be replaced. There is also a spring at one end which keeps them from wandering left/right.

If the whole she-bang has worn to the point that it needs to be rebuilt at the tube on which the bushings ride...well, anything is possible, but it is on the unlikely side of things. If you hold the swinging arms (you'll need to do this from under the cab) at the top where they attach to the pedal rods and try to rock them side to side in an arc, what happens? You ought not get much play at all doing this.

I did my bushings and found the shaft was not worn just the bushings .the new bushings i got were oversized and needed to be fitted l spent hours doing it by hand a socket and sandpaper .I tried a wheel cylinder hone and it did not work very well .There used to be two types of bushings oversized and stock size .the old ones were dimpled and the new ones were solid . Worked out in the end lots of elbow grease without proper reamer tool

Make sure that your front cab supports aren't collapsed. Also check the condition of the rear cab mounts. A cab out of wack will cause the pedal shafts to rub the cab holes.

Good point. Be sure the pivots/bell crank/bushings are actually loose. Rubbing can be caused by other factors, as Carl points out.

Thanks guys. The mounts are rock solid and the pedal arms rubbed even when they weren't attached to anything. I need to pull the trans out, so I'll take a look at adjustment possibilities when I'm under there.

That's very encouraging, Mark. Mounts are a possibility I almost mentioned, but it is down on the list (fortunately). If your mounts have deteriorated to that point a couple of other things will be large red flags, and I don't think there's any way you wouldn't have noticed them.

One suggestion: if you have the chance to take this to a coin-op car wash you might do so and clean as much down there as possible. Decades of migrating brake fluid and grease mixed with road dust can make this area messy. Another comment: the arms travel in a natural arc and the pedal rods are also bent into that same arc, so there is a "happy spot" those must travel in and it isn't all that forgiving. Recently I noticed my brake light was staying on and it turned out to be a bit of the new pedal seal I installed had become caught between the rod and the hole. Added to that, the return spring wasn't quite strong enough to pull the brake pedal back as sharply as it should, so I added an extra spring down there. That tube (or steel rod, basically) that your brake and clutch arms pivot on is one tough piece of metal...incredibly tougher than the bushings, so it isn't likely to have worn out. Good luck!

Good info. Thanks Jon

Agree, but if you get enough grit in there, they will wear some. My original had some definitely visible wear on it, so I swapped it for another one off a later frame I had that had some very slight wear marks. I just put in the pedal bushings that were advertised as undersized to compensate for worn shafts, but they were a good fit on the shaft that had maybe 2-3 thousandths wear (I didn't measure it.)
My pedals had worn the upper part of the holes where they go thru the firewall, but then my front cab mounts were basically non-existent. The arc-shaped pedal arms can only go on the straight arms with the bushings, because they have grooves in the mating parts where they bolt together.