Comprehesive howto for brakes?

[freak]

1930. My brakes are very weak. I tried to adjust them with the service manual and I still get very weak brakes. I have watched Paul Shinn's adjustment video and I think I'll run out of rod before I get them tight enough. Surely because of inexperience with these mechanical brakes. I don't know what to look for as far as worn components. Not sure the arms on the backing plate are adjusted. Can they be adjusted? Maybe drums are warped? Really need to get these working better but don't know where to start. Seems like starting out by adjusting rods is not good unless everything else is adjusted. Need help!

[nkaminar]

Others will chime in and help. Here is my input.

Ford adjusted the lengths of the rods at the factory and advised in the service bulletins that they were not to be changed in length by the dealer or owner. If needed they could be adjusted to a specific length by then not touched again. This is contrary to a lot of instructions found on the web and other places. All brake adjustments were to be made by the brake adjusters.

I have checked the length of my rods to provide the correct angle of the levers, for instance 15 degrees forward at the front, and then not touch the lengths.

Ford advised to turn the adjusters in until the wheels start to drag and then turn them one notch out.

Check the free movement of all the brake parts. The shafts for the brake arms should turn freely and not be excessively loose in the bushings. Grease helps.

The shoes should move out easily when the brake lever is moved. Check this with the drums removed. If there is binding, correct that.

Check the condition of all the parts. The wedges in the front should be in good condition. Check that there is adequate lining on the brake shoes. Check the condition of the drums. If they are stamped steel, replace with cast iron. Check the fit of the shoes in the drums. They should make full contact.

Check that the shoes are centered. There are tools available to check this that come with instructions.

If the shoe linings are glazed, take some 80 grit sandpaper and remove the glaze.

Good luck with your project and be sure to report back with you success.

[whirnot]

Originally Posted by nkaminar

Others will chime in and help. Here is my input.

Ford adjusted the lengths of the rods at the factory and advised in the service bulletins that they were not to be changed in length by the dealer or owner. If needed they could be adjusted to a specific length by then not touched again. This is contrary to a lot of instructions found on the web and other places. All brake adjustments were to be made by the brake adjusters.

I have checked the length of my rods to provide the correct angle of the levers, for instance 15 degrees forward at the front, and then not touch the lengths.

Ford advised to turn the adjusters in until the wheels start to drag and then turn them one notch out. .

And that's why you should not take your instruction from someone on you tube.

[700rpm]

The Service Bulletins are good for learning what was important to know when the Model A was new. They are not a guide for how to restore a 90 yr-old vehicle. That is not to say they should not be consulted during restoration or maintenance, because specs and tolerances and such are still relevant. But they should be only one book in a library of restoration references, including MAFCA and MARC publications and private books like Les Andrews’s series. Also, if one is new to the Model A it is wise to join a local club, where years of experience and assistance are available that can help you through the arcane and antique peculiarities of making these exceptional machines work properly, even after nearly a century on the road.

[freak]

Originally Posted by nkaminar

Others will chime in and help. Here is my input.

Ford adjusted the lengths of the rods at the factory and advised in the service bulletins that they were not to be changed in length by the dealer or owner. If needed they could be adjusted to a specific length by then not touched again. This is contrary to a lot of instructions found on the web and other places. All brake adjustments were to be made by the brake adjusters.

I have checked the length of my rods to provide the correct angle of the levers, for instance 15 degrees forward at the front, and then not touch the lengths.

Don't you have to set the 15 with the pill first?

Originally Posted by nkaminar

Ford advised to turn the adjusters in until the wheels start to drag and then turn them one notch out.

I was pretty sure the service manual said turn in to drag then back out 2-3 clicks.

Originally Posted by nkaminar

Check the free movement of all the brake parts. The shafts for the brake arms should turn freely and not be excessively loose in the bushings. Grease helps.

The shoes should move out easily when the brake lever is moved. Check this with the drums removed. If there is binding, correct that.

Check the condition of all the parts. The wedges in the front should be in good condition. Check that there is adequate lining on the brake shoes. Check the condition of the drums. If they are stamped steel, replace with cast iron. Check the fit of the shoes in the drums. They should make full contact.

Check that the shoes are centered. There are tools available to check this that come with instructions.

If the shoe linings are glazed, take some 80 grit sandpaper and remove the glaze.

Good luck with your project and be sure to report back with you success.

Thanks I'll be checking everything more.

[freak]

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Originally Posted by whirnot

And that's why you should not take your instruction from someone on you tube.

I was under the impression that Paul Shinn's video was the go to for brake adjustment.

[700rpm]

Originally Posted by freak

I was under the impression that Paul Shinn's video was the go to for brake adjustment.

Always good to get a second opinion. There are a lot af variables in the brake system.

[alexiskai]

I think P.S.'s procedure is an attempt to get decent brake performance out of cars with a wide range of actual brake components without taking the brakes apart. Adjusting the rod lengths compensates for the different wear levels on the individual brakes. The point is to equalize the braking force from each wheel and roughly calibrate it. In contrast, the official procedure – such as the directive to set the rod lengths so they align with the levers at 15° forward – is designed to maximize the braking force by optimizing the physics.

The official procedure assumes that your brake shoes, operating wedges, levers, etc., are all within official tolerances. Shinn's procedure is designed to be used at club events with random cars showing up. You can't stop and replace any parts at these events, you're just trying to get the best performance possible under the circumstances. It's a fine procedure for that scenario, but I agree that I wouldn't use it when overhauling my own brakes in my own garage.

[freak]

Originally Posted by alexiskai

I think P.S.'s procedure is an attempt to get decent brake performance out of cars with a wide range of actual brake components without taking the brakes apart. Adjusting the rod lengths compensates for the different wear levels on the individual brakes. The point is to equalize the braking force from each wheel and roughly calibrate it. In contrast, the official procedure – such as the directive to set the rod lengths so they align with the levers at 15° forward – is designed to maximize the braking force by optimizing the physics.

The official procedure assumes that your brake shoes, operating wedges, levers, etc., are all within official tolerances. Shinn's procedure is designed to be used at club events with random cars showing up. You can't stop and replace any parts at these events, you're just trying to get the best performance possible under the circumstances. It's a fine procedure for that scenario, but I agree that I wouldn't use it when overhauling my own brakes in my own garage.

What exactly is the 15° measured from? Just with the slack taken out of the lever? Hold it backward all the way without exerting any real force? Then it should be at 15°? And furmore... to get to 15 is the only adjustment "the pill"?

[nkaminar]

Freak,

To answer your question, after setting my rods for 15 degrees lever position, I had to add a spacer (pill) to be able to adjust the brakes.

[Bob Bidonde]

Do not mess around with your brakes if know not how they work and how to restore them. Take your Model "A" to a knowledgeable club member or restoration shop and have the brakes done right and safe.
All of the above advice is well intended, but unless you have knowledge and experience, the advice is like a foreign language - strange!

[alexiskai]

Originally Posted by Bob Bidonde

Do not mess around with your brakes if know not how they work and how to restore them. Take your Model "A" to a knowledgeable club member or restoration shop and have the brakes done right and safe. All of the above advice is well intended, but unless you have knowledge and experience, the advice is like a foreign language - strange!

One thing that's nice about brakes is you can do it through the mail. The rears in particular are hard for a novice to rebuild. I sent those to Randy G. I did my own fronts, but I sent them off to be arced.

[freak]

Originally Posted by Bob Bidonde

Do not mess around with your brakes if know not how they work and how to restore them. Take your Model "A" to a knowledgeable club member or restoration shop and have the brakes done right and safe.
All of the above advice is well intended, but unless you have knowledge and experience, the advice is like a foreign language - strange!

I've done many a brake job. Just not on my A. I'm quite an experienced mechanic but there's always something you haven't seen. I'm confident I'll get it working correctly.

[Y-Blockhead]

One of the biggest improvements I made to my brakes after checking and replacing any worn parts and shoes and adjusting was to replace the steel drums with cast iron drums.

Most 90 yo steel drums have been turned one too many times (even states in the Service Bulletins NOT to turn them) which is one of the causes of brake fade.

[nkaminar]

Freak,

Adjust the lengths of the rods first to get the 15 degrees from vertical in front. I forget what is is at the back but the principle is to get the best leverage. If the levers are not near vertical when applying hard braking then you are not getting the best mechanical advantage.

After that, and assuming you have completed all the repairs as needed, try adjusting the brakes starting with the adjusters all the way out. If you cannot get them to adjust then add a pill, but do not change the length of the rods.

If you are a mechanic then you should be able to get the brakes working well enough to lock up the wheels. As in any mechanical system just make sure everything works freely, that no parts are excessively worn, and that the shoes fit to the drums.

And, as blockhead said, use cast iron drums.

[freak]

Originally Posted by nkaminar

Freak,

Adjust the lengths of the rods first to get the 15 degrees from vertical in front. I forget what is is at the back but the principle is to get the best leverage. If the levers are not near vertical when applying hard braking then you are not getting the best mechanical advantage.

That's part of what I'm having trouble with. With the rod disconnected, the lever (or arm) on the backing plate stands straight up with no force applied. Only when moving past straight up will the brakes start being applied. So to adjust the lever to 15 (without even dealing with the rod yet) is where I am confused.

[Ruth]

Originally Posted by freak

That's part of what I'm having trouble with. With the rod disconnected, the lever (or arm) on the backing plate stands straight up with no force applied. Only when moving past straight up will the brakes start being applied. So to adjust the lever to 15 (without even dealing with the rod yet) is where I am confused.

You need to add a pill(s) to the actuating rod to get it 15° forward, then reconnect the rods.

or replace the operating pins if they are worn excessive. Should be 7¼" long. I actually had a bent one that was causing me heartburn.

Purdy Swoft had a good brake setup procedure that I always follow with great success.

[freak]

Ok thanks. I think that's what nkaminar was saying too.

[Ruth]

Originally Posted by nkaminar

Freak,

To answer your question, after setting my rods for 15 degrees lever position, I had to add a spacer (pill) to be able to adjust the brakes.

Originally Posted by freak

Ok thanks. I think that's what nkaminar was saying too.

I think nkaminar was saying it opposite. I think you have to set the 15° before you set the rod length. You don't set the lever 15° by adjusting the rod length, you do that with the pill(s).

[Y-Blockhead]

Purdy's Brake adjustment procedure has always worked for me. And yes, the 15° lever position must be correct before you start. Add pills or replace parts as needed to reach 15°.

No, Purdy does not use the "Brake Board".


Purdy’s Brake adjustment

Here is what works for me, even if there is wear in the system. Disconnect all of the service brake rods at the clevis end. Adjust the brake pedal rod so that the brake switch plunger is 1/16 inch from the inside back of the center cross member with the brake pedal at the top of its travel. This is where the pedal rod plunger contacts the brake light switch on the 30-31 models. In extreme cases, to give more threads at the clevises it may be necessary to adjust the pedal rod all the way back to the center crossmember without the 1/16 gap. Because there will nearly always be some wear in rear wheel bearings and axle housing bearing races, I first adjust the rear brakes. With any wear, rear brake adjustments made with the rear wheels off the ground will be TOO tight with the wheels on the ground. With the tires properly inflated for easy roll, I adjust the rear brakes with the tires on the shop floor. You only want very slight drag if any or the brakes will quickly overheat. Unless something is too tight, wheel bearings, brakes or the tires are low, a man should be able to slightly push the car back and forth by hand while making adjustments at the rear wedges to determine brake drag. You don't want much drag. After the rear brake adjustments at the rear wedges have been made Move to the front. With jack stands under the front axle, adjust the front brakes at the wedges until the brakes lock and back off as needed .You can check brake action by spinning the wheel and moving the brake lever by hand before connecting the brake rods. After the front wedges are adjusted, its time to move on to the brake rod connections. If you want good brakes, BELIEVE me, forget about any exact measurement here!!!!!!! The brake rods need to all be adjusted at the clevis ends so that the clevis pins will just enter the pinholes with ALL slack removed. This setup will have the pedal at the top of its travel and ready to put the lining to the drum. There is no need to concern yourself about whether the rear brakes engage first, its built in. I guarantee that if the brakes are right or even have some wear this setup will give very good brakes. anything less will not. In testing and as new parts wear in, adjustments will need to be monitored I usually make panic stops in sand or dirt to gauge skid marks and adjust as needed.