Evening Adjustment for Brakes

[Mike1291]

I'm having a hard time understanding why my rear brakes are at the very end of their adjustment while my front brakes have plenty of room on the rods. My cross shaft is what I think is the correct angle and the brake arms appear at the correct angle (about 15 degrees to the right). My front pedal is also adjusted at the pedal though that clevis is barely on the threads (plenty of inward adjustment). I adjusted the brakes according to Les Andrew's book, but with a front brake bias.

I have the ability to take off my rear hubs now and was looking for feedback as to what I should check.

 

[nkaminar]

Is the car stopping OK? It sounds like the rear shoes need to be re lined, but you will only know that after taking the drums off.

 

[Mike1291]

Yes the car stops well but has a little more pedal travel than I'd like. I had to make a compromise by adjusting the car based on my limited adjustment in the rear.

In 2024 I put on new shoes, rollers, etc. I also checked the adjusting wedges, adjusting shafts, operating pins for the shoes, and replaced as needed.

 

[Y-Blockhead]

Your first picture - The actuating arm should be straight up and down, not at an angle. Adjust at the pedal, then re-adjust your brake rods per Purdy Swoft's instructions.

I see this a lot because it is not mentioned in Les Andrew's book or the YouTube channels.

See figure 413, page 203 of the Service Bulletins.

 

[Mike1291]

Thanks Y-Blockhead. I'm going to do as you say but I might have an issue with my brake light switch being on all the time.

I also found a nice illustration of all four wheels in the bulletins as well.

 

[Y-Blockhead]

Thanks Y-Blockhead. I'm going to do as you say but I might have an issue with my brake light switch being on all the time.

I also found a nice illustration of all four wheels in the bulletins as well.

Hmmm, you shouldn't but who knows. The brake pedal rod plunger should be ~1/16" from the cross member.

 

[Keith True]

You need to get those cross shaft arms vertical before you do anything else.You can deal with the brakelight switch in whatever way you can come up with,but not by taking those arms off the vertical position.Also,when you are looking at the cross shaft make sure it is not hitting the driveline when it swings.

 

[Jim/GA]

I'm having a hard time understanding why my rear brakes are at the very end of their adjustment while my front brakes have plenty of room on the rods.

You mention adjusting the rods but you do not mention turning the brake adjusting screw that sticks out of the backing plate. Are you turning that also?

 

[JoeCB]

At the risk of starting a heated discussion about the position of the brake actuating arm it seems that the optimum "at rest" position should be just forward of vertical. The reason being that maximum mechanical leverage is achieved at the vertical position. Initially positioning the lever, a bit ahead will allow for the take up of any slack in the system before reaching the maximum leverage position of true vertical, thus exerting maximum leverage at the point of brake engagement.
Joe B

 

[nkaminar]

I see a lot of work here. The rods should be set up as the service bulletins show with the lengths as indicated. If the pins and other parts are worn, that should be corrected first. The brakes should only be adjusted using the adjusters. If they do not adjust correctly then there is something worn or wrong in the brakes that should be corrected. The red book shows how to fix things.

 

[Big hammer]

Thanks Y-Blockhead. I'm going to do as you say but I might have an issue with my brake light switch being on all the time.

I also found a nice illustration of all four wheels in the bulletins as well.

The brake rod return springs ( commonly known as anti-rattle springs ) probably are NOT pulling the brake rods back towards the brakes on each axle, this will pull the brake pedal back and also actuate the brake light switch .

IF the brakes stop you straight ahead and not pulling one way and your complaint is the pedal has too much travel, shorten the rod between the brake pedal and cross shaft. Oil the clevis pens rod ends at each connection may help with the return springs not pulling the rods back towards each axle.

When adjusting brakes support your car under the front and or rear axle, IF the axle is hanging down and you adjust the brakes ,when you lower the car your brakes will be too tight !

I really dislike commenting on brake issues because of liability ! GO SLOW and easy testing after any brake work !

 

[Mike1291]

I shortened the rod between the pedal and the cross shaft about 20 turns on the clevis pin (it was all the way out) and now my cross shaft looks like the Service Bulletin. Thanks for those who suggested checking that.

Now as for the brake light switch - since my car is a 31 it's mounted on the cross member. Currently the plunger is more than 1/2 inch away from the frame, which means my light switch will be on all the time now. My pedal is all the way up in its travel, so it doesn't need a return spring (at least in the current configuration).

Is there something wrong with my cross shaft or the cross shaft rod?

 

[Keith True]

Sounds like somebody lopped a little off the rod to fit the situation.Over the years those rods get lengthened,shortened,bent,and twisted to fit at the moment.You can add onto it and make it work.But,do that after you've adjusted everything according to the service bulletins.

 

[Big hammer]

Synder’s catalog online says the pedal to cross shaft should measure 16 inches from the mushroom ( switch end ) to the threaded end at the pedal . Disconnect the brake light switch and get the brakes adjusted !

 

[Mike1291]

I checked the rod and it's exactly 16 inches, from mushroom to the end of the threaded rod.

Asked a local club member and he mentioned something about maybe a wrong pedal or a wrong pedal shaft on my transmission. Not sure if that makes sense though.

 

[Diastole]

At the risk of starting a heated discussion about the position of the brake actuating arm it seems that the optimum "at rest" position should be just forward of vertical. The reason being that maximum mechanical leverage is achieved at the vertical position. Initially positioning the lever, a bit ahead will allow for the take up of any slack in the system before reaching the maximum leverage position of true vertical, thus exerting maximum leverage at the point of brake engagement.
Joe B

Does anyone have thoughts on this poster’s comment about mechanical advantage of the lever arms and their at rest position being forward of vertical?
Despite what Les Andrews and the Service Bulletins say.

Diastole

 

[philosofriend]

I suspect that unless your pedal has too much depression before the brakes engage that putting the cross shaft lever leaning forward would not make any difference. There shouldn't be that much slack in the system.

After the initial setup, slack should be taken out of the system as the lining wears by tightening the square adjusters on each wheel. All other adjustments are major initial set-up work, not normal minor adjustment.

When my A had mechanical brakes, whenever the pedal seemed to have too much depression before anything happened I would put on my work clothes, get a wrench and do the following: Coast down a big hill that is going to need a lot of braking. At the bottom immediately pull into a parking lot and cautiously try touching each brake drum. If any of the drums were noticeably cooler than the rest, tighten the adjuster on those wheels two clicks. This always restored the pedal. Then, drive home carefully and slowly trying not to use the brakes at all. Feel the drums, a hot drum would be dragging and the adjuster at that wheel needed a click taken out.

 

[Y-Blockhead]

When my A had mechanical brakes, whenever the pedal seemed to have too much depression before anything happened I would put on my work clothes, get a wrench and do the following: Coast down a big hill that is going to need a lot of braking. At the bottom immediately pull into a parking lot and cautiously try touching each brake drum. If any of the drums were noticeably cooler than the rest, tighten the adjuster on those wheels two clicks. This always restored the pedal. Then, drive home carefully and slowly trying not to use the brakes at all. Feel the drums, a hot drum would be dragging and the adjuster at that wheel needed a click taken out.

I use a digital thermometer from HF to measure the drum temps. Saves on the digits…

 

[philosofriend]

Yea, you hold your hand about two inches away for a few seconds, you can sense if it is too hot to touch, a thermometer would be much smarter.

Somehow this reminds me of the neighborhood kid a year older than me who earned my unending respect when we were fooling with a lawnmower. We got it started but there was no apparent way to stop it. He casually reached down and pulled the wire off the spark plug with his bare hand.

 

[Y-Blockhead]

Somehow this reminds me of the neighborhood kid a year older than me who earned my unending respect when we were fooling with a lawnmower. We got it started but there was no apparent way to stop it. He casually reached down and pulled the wire off the spark plug with his bare hand.

Haha, in my youth I worked with an older mechanic who would just pull the spark plug wire off with his hand to determine which cylinder was missing. Learned a lot from him but I only tried that trick once...