The brake pedal shaft has a hole in it. A pin goes there, and attaches the shaft to a stirrup. The stirrup is part of the master cylinder. The pedal shaft pushes into the Y of this stirrup. A person might think that if that pin falls out, the brakes will still work, pushing against the rod even without a pin.

Except that if the pin falls out, the pedal springs toward you, and disappears up under the dash right behind the steering column. You will reach for the brakes and your foot will find air. No pedal anywhere. You have to tilt your head to one side to even see where it has gone to.

I didn't hit anything, but from now on I will keep an eye on the cotter key that keeps that pin in place. And I squeezed the stirrup together so there's no pressure rubbing against the cotter key.

Rick;

This certainly makes the point of how important that lowly cotter pin is...I typically replace cotter pins with "hitchpins" of the appropriate size (including at that clevis... even the one on Brakedrum nut)...these are a bit beefier, and not split, but solid and can be reused indefinitely...this seems to me to be more consistent with the philosophy of the entire car!

To Derek's mention of point-of-wear...since the clevis pin makes contact edge-on on both pedal and yoke, these edges are susceptible to wearing the holes in the pedaltube oval (after a few hundred thousand miles, and a few hundred million pushes of that pedal...damn...those Volvos just don't last!)...a dab of grease on these wear areas keeps the rate of wear to a minimum. HA's suggestion of adding a bushing would be a possible solution as it increases the bearing area...I'd be real careful about taking any material away, or weakening pedaltube further in any way by drilling...I think I'd prefer opening up the hole only enough to TIGging in a steel bushing with a close ID clearance for the clevis pin, and grease that...I don't think a full-blown bearing is really necessary here...

Cheers

Since you are PUSHING on the clevis, a minor reduction in the section doesn't make
much difference as long as it stays in place. There is little or no tension on the
reduced section (only what the spring provides).

I've had brakes completely fail on me 3 times in my life. Certainly gets your heart pumping.

Bonus points have to go to the PV, which was kind enough to have the hand brake mechanism fail when I rather excitedly pulled on the hand lever.
--
'63 PV544 rat rod, '93 Classic #1141 245 (now w/16V turbo)

My brakes failed once, and once was enough.

Leaking rear wheel cylinder, the car parked pointed in the direction I needed to go, and I jumped in and started to go. I didn't need the brakes for a couple of hundred yards down the road when I had to slow up for a stop light. Pedal to the floor (all the fluid leaked out of the MC), emergency brake wasn't adjusted right (was pulling like a maniac on it), turned off the engine, rear end of the car that was infront of me coming up fast, luckily, nobody was coming the opposite direction (which is where I ended up), when I finally stopped, I was even with the driver that was stopped at the light in front of me (I was in the wrong lane).

Paul

My brake failure on the road occurred on the NY Thruway -- approaching a toll plaza in an air cooled VW Beetle--the cause was the same type of pin through a clevis that came apart--luckily Beetle hand brakes really do work. -- Dave

First time for me was on my old 122 (second car I ever owned). The pins retaining the front pads fell out, and they rattled out and started scraping against the inside of the wheel. I decided the sound was worth checking out, went to slow down and pull over - oops! Not too exciting, on a straight road, nothing ahead, I was able to just slow down and pull over without getting too excited.

Next time I'd been hearing a light scraping/squealing sound from the front end of my winter beater Bronco II. Looked a time or two, didn't really see anything. Then one hot summer day I was approaching a sharp left hand curve in the road and went to apply the brakes, and nothing (split circuit brakes too - huh). Post mortem diagnosis on that one was a sticking RF caliper that got hot enough to boil the fluid, which must have blown a steam bubble back through the lines and emptied out the master cylinder somehow, since the rears didn't work either.

And the PV, this one was purely my fault. I'd done a complete overhaul on the brakes (car had sat for 17 years in a carport prior to me getting it). New wheel cylinders all the way around, new shoes, new master cylinder rebuild kit, new rear drums. Got it all together, all worked great, no problems for about a week. then I was zipping along on an overpass, in the left turn lane, approaching a line of cars stopped in my lane waiting to turn left. Put the brakes on a little more firmly, got some braking, then bam, pedal lost pressure and went to the floor. Pumped, nothing. Cars coming up fast! Hauled on the handbrake, and something popped loose under the car and it loosely pulled all the way up. Luckily, there were no cars in the lane to the right of me (going straight), so I was able to (in the nick of time) swerve hard right and avoid the cars, sailed through the intersection (I honestly don't recall if the light was red or green, but I didn't really have a choice in the matter at that point) then just geared down, down, down, pulled over in a parking lot and tried to settle my heart rate and adrenaline level back down. Post mortem on that was that the little slotted pushrod on the rear brakes that goes between the shoe and wheel cylinder piston must have been just sitting on one of the 'ears'. Worked fine for a while, but the first time I pushed a little harder than normal, the ear bent over and popped off the shoe. Then the wheel cylinder piston popped out and released all the pressure. After that, i sort of learned to slow down my wrenching, do it in shorter batches, be a lot more careful. I'd done all the brakes in one sitting, including an epic battle with the rear drums, and I'd simply gotten sloppy on the last one I did, being tired, stressed out (really struggled with those drums), and wanting to be done.
--
'63 PV544 rat rod, '93 Classic #1141 245 (now w/16V turbo)

The correct name for the "stirrup" is clevis.
"Yep, Maltby's Hardware store can fix you right up if you need a wick for your coal oil
lamp or a clevis for your walkin' plow, but don't go there lookin' fer no grade 5 bolts!"

Also the brake pedal shaft is what both the brake and clutch pedal pivot on.
What came out due to the lost cotter pin was the clevis pin.

I wonder if it would be worth putting a "leash" on the pedal, perhaps a little bit of fishing line or a spring, to prevent the pedal from entirely departing the center of the clevis in the event of a failure?

Better solution would be checking the clevis, pin and cotter or spring pin on a regular basis. I usually fit a small washer between the cotter pin and the side of the clevis, to reduce the wear of the one against the other.

The reason the clevis pin dropped out was the failure of the the split pin and and it's disappearance. Definately one where the instruction "always fit a new split pin" should be followed. Can happen on the clutch as well. The holes in the clevis wear oval which gives too much movement in the pedal before anything happens. The position can be adjusted on the push rod. The clutch clevis wears the worst and AFAIK they are NLA. I'm in the UK but will buy a couple of sets for brake and clutch from "anywhere" if they are available. Must be the correct ones though. You can lose close on 1 1/2" at the clutch pedal when the wear is bad which makes the the clutch action short and very unpredictable. Currently I've got mine adjusted out to the limit and it's OK but it needs changing to a new or better one.

Rather than replacing the clevis, due to the ovalling of the holes, could the clevis be machined, not drilled, to press fit a bronze bushing or even better a small roller bearing? I assume it would require 4 altogether, never having seen the particular clevises in question.

I did something like this with my 65 jeep cj5. The cluth was operated mechanicaly by a series of
rods-bent at the ends and just shoved thru a drilled holes with no accomodation for lubrication or adjustment. I rigged up a new set up, much like a bell crank, with a step down bushing I got at a plumbing supply house and some pipe. I added a zerk fitting to the main shaft and it all worked perfectly. One of my prouder moments.

Clevis and pin arrangements are often used in linkages and farm machinery.

I am not sure of any exact interchange, but I would not be at all surprised if a farm supply or similar hardware store had the parts to build a comparable arrangement. Hopefully out of stouter materials.

As for fitting a bushing or bushings, I suspect it could be done easily at the same time, and with the right replacement clevis, would only require drilling the pedal itself. In fact, a larger pin might wear less simply because it has a larger bearing surface.

As part of my braking upgrades, I've been playing with different setups at the wheels...maybe I should look into different setups at the pedal, too!

I installed a MC from a 940, and a brake switch kit from Swem (Ron Kwas) and added a piece of flat bar to keep the brake pedal from swinging out:



Paul

Paul;

Nice installation!...that's about how it should look...you make an interesting point about the beneficial side-effect of the Brake-Light Switch Upgrade, in that it prevents the pedal from swinging up and under the dashboard with the loss of the clevis pin (I doubt it would do much to help keep your brakes though...

Your full crossbar mod is how the kit for the Automatic Trans is made also...it's not normally necessary on manual Trans installations...what is that control cable going through the former Ignition Coil hole controlling...your nitrous valve?...just kidding...it looks like a throttle cable from an injection system...

Cheers

Ron,

If that the correct mounting position for your brake switch? I still haven't installed mine yet, because I don't know where the best place to mount it is. Do you have any pictures?

My email is luke.j.ball@gmail.com

Thank you.
--
1959 Volvo Amazon 121

That looks like a good setup. I should have said I've been modifying the HYDRAULICS as opposed to "at the wheels". I'm running a 1980 RX-7 master cylinder, and manual proportioning valve to adjust the rear brakes bias. In front I've converted to a late '90s Mustang caliper and rotor; in back I'm using a Ford 7.5" rear axle with 9" Ranger drum brakes. I've got a similar brake switch to Ron's mounted on a bracket in front of the pedal; it has open and closed circuits so I can use it both for brake lights and to shut off the cruise control.

Ron's idea of greasing the pivot is a good one. If I have problems with the hole getting wallowed out then I'll sleeve it, make a pin from high-carbon steel and drill it out for a grease nipple.

Hey!

I know somebody looking for information about the Ford rear axle upgrade. He tried John Parker, but never got the answers he was looking for.

I think he needed to know what Ford's to get the axle from. Do you have any pictures or info about the conversion you can give me?

Paul

I'm doing mine a bit differently than most.

I've got an old Ford Ranger rear axle (7.5" ring gear, not the heavier 8.8...I'm not putting out that much power) with 10" drum brakes. The Ranger shares our 5x4.5" lug pattern.

The Ranger axle is set up with the differential offset. The SHORT side of the axle is just right for the 122. So you need to shorten the long side and replace the axle shaft with a second short side axle shaft (about $100 new, or grab a second Ranger).

While you're at it, collect the two LONG axle shafts, because Ford Fox-body Mustang/Fairmont/Zephyr/LTD etc guys use those to swap to 5-lugs in the back (I actually got mine as an accident of Fox chassis ownership, I've got a converted 1980 Mercury Z7 Zephyr).

You'll need to match up the brackets for the springs, shocks, and panhard bar, and have the driveshaft made the right length and flange for the Ford axle. Lastly, you'll need to play with the parking brake cable ends to match them up to the Ford brakes.

It sounds like a lot of work, but what I've been doing is collecting the parts free/cheap, I've already started measuring and marking where the brackets will need to be. Although I can weld, I'd rather have the suspension parts welded by a professional welder.

I expect I'll have maybe $300-350 into this by the time it's done...compared to the $500 a pair of new brake drums for a 122...if the price is still the same and they are still available.

Brake parts would then be in the $35 range for a drum, $15 for the shoes, $10 for hardware, and all off the shelf for a 1983-2002 Ranger, in stock today at your local parts place.

I don't expect a real improvement in braking power; for me this is a logical path to follow for a daily driven car where historical accuracy and overall parts longevity are second to enjoyability and availability. Waiting 2 weeks for a $250 drum is fine on a second car. Having a warehouse would be fine but I'd rather let NAPA or Advance Auto be my warehouse.