sportroadster Posted January 11, 2018 Share Posted January 11, 2018 I am new to pre-war cars and to mechanical brakes is particular. Bought a 28 Buick a few months ago, it is in nice shape but braking seemed to have only 1 wheel that was braking and locking up. Got all wheels adjusted per the manual now have both rears that can lock but front barely have enough leverage on them. I can still turn the fronts by hand with all four wheels up in the air and rears locked Checked the evener and rod from pedal is connected to hole closest to front wheel brake rods Checked for friction and found some issues but all are resolved with same results So what is next, drill a new hole in the evener closer to the front brake rod side? Open to any suggestions Will Link to comment Share on other sites More sharing options...
Bob Engle Posted January 11, 2018 Share Posted January 11, 2018 My first question on mechanical brakes is "Do you have the correct woven lining on the brake shoes??" I have seen too many relined shoes with bonded lining . The compressed bonded linings require too much pedal pressure to work properly on the mechanical brake systems. Model A Fords are set up so the front wheels don't lock up. The concern was loss of steering with locked front wheels. If your car can skid the rear tires on a panic stop, you probably have as much braking as you can expect. Bob Engle Link to comment Share on other sites More sharing options...
Guest Posted January 11, 2018 Share Posted January 11, 2018 Most of my brake adjustment books suggest if part of the system is locking up and part is not that you should back off the one/ones that are locking. Tightening up the ones that don't lock up is the wrong way. Bob Engle is right about the linings. My Pontiac locks all four wheels with half a pedal (now that I have gone back to the correct linings) and on a government MV inspection my braking is 60% front and 40% rear. Link to comment Share on other sites More sharing options...
hidden_hunter Posted January 11, 2018 Share Posted January 11, 2018 37 minutes ago, Tinindian said: Most of my brake adjustment books suggest if part of the system is locking up and part is not that you should back off the one/ones that are locking. Tightening up the ones that don't lock up is the wrong way. Bob Engle is right about the linings. My Pontiac locks all four wheels with half a pedal (now that I have gone back to the correct linings) and on a government MV inspection my braking is 60% front and 40% rear. That was our experience with the 1926, basically we ended up having to do a couple of passes around the car making adjustments to get them right. If the material is slightly out of round it's also difficult to get them even but it should wear off the high spots pretty quickly when adjusted properly. Also make sure that your rears aren't dragging Much easier on the 22 cad.. no front brakes to worry about Link to comment Share on other sites More sharing options...
DavidMc Posted January 11, 2018 Share Posted January 11, 2018 The comment above by Bob Engle might imply that the correct woven linings are not bonded. I have those woven linings on two cars, both with band brakes and they are both bonded. I agree however that the lining material used on cars with hydraulic brakes are not suitable for the mechanical brakes. Link to comment Share on other sites More sharing options...
Roger Barrett Posted January 12, 2018 Share Posted January 12, 2018 Get a copy of the shop manual for the car and adjust the brakes per the instructions there. Follow every step. There are a bunch. Things get changed over the last 90 years and the geometry of the linkage is compromised. As others have said it's important to have the correct linings and of course no oil on the brakes. Link to comment Share on other sites More sharing options...
sportroadster Posted January 12, 2018 Author Share Posted January 12, 2018 Thanks for all of the suggestions. I bought the car from an estate sale, so I cant ask the previous owner about the brake lining. The Buick has external band brakes so easy to see the linings and they look almost new on all 4, and they do work on the rears. As an aside the parking brake are internal shoes on the rear and easily lock up the rear. Did all of the adjustments per the manual and I can get the fronts, and rears. to lock up by manual pulling on the brake cable/rod of the individual wheel. Did the recommendation of loosening the rears and tightening the fronts which did nothing. After studying the brake system some more notice there is an "evener" in the system which as the word says is supposed the evens the brake load front to rear. I also have draft horses and wagons and we use eveners on all of our wagons to even the loads between 2, 3 or even 4 horses so I am familiar with them. By offsetting from the middle you can lighten the load for the horse which has the greatest moment arm, same would apply for front and rear brakes which is why I am considering offsetting from the middle of the evener. Do model A's not use a evener in the brake system? Guess I'll just try to drill some new holes in evener to see what happens, removing floor does not seem too bad to gain access to evener. Thanks again. Will 1 Link to comment Share on other sites More sharing options...
Grimy Posted January 12, 2018 Share Posted January 12, 2018 +1 to getting and studying a manual, preferably BOTH the Buick manual and the ca. 1930 all makes manual which has some field lessons-learned in it. The GEOMETRY of the components is most important. I spent a lot of time identifying and correcting well-meaning but very wrong modifications to rods on my 1925 Pierce, which had been resting for 10 years. Here are a few examples, which may or may not translate to your Buick: 1. The cross shaft under the drivers seat on my car has a lever on each end (pedal and rod to rear brakes) and the shaft must be able to move freely within its cast iron housing. It was stuck. I removed the assembly, let it soak for a week in solvent, then tapped off the levers, and drove the shaft out of the cast iron housing with some difficulty. I then burnished the shaft, which is a close fit to the housing, and used bore brushes to clean out the ID of the housing. Added penetrating oil, tapped shaft back into housing, attached levers, worked it back and forth, adding penetrating oil through the oil holes in the housing (no oiler fittings), and after a long time had it working smoothly. 2. At the rear of that car are levers which operate the rods to the cams within the drums (internal shoes). According to the books, the resting position of these rods is 45 degrees to the rear, and at full application of brakes they are vertical. These positions are essential for proper mechanical advantage (lever and fulcrum). 3. Free operation of pivot pins for external contracting brake shoes is essential. In service, I find I need to grease them at 400 miles. 4. Disassemble, clean, polish and oil EACH clevis pin. 2 Link to comment Share on other sites More sharing options...
Gary W Posted January 12, 2018 Share Posted January 12, 2018 There is no "evener" on the Model "A". Brake cross shaft, levers at the ends. The actuating levers at the wheels MUST not be straight up and down. As Grimy said, they should be at least 15 degrees forward so you get the mechanical advantage. In the Model "A" you can add "brake pills" to the bottom of the push rod to effectively move the lever forward. (Front brakes). and yes, no slop anywhere with mechanical brakes. Every small bit of slop multiplies throughout the system. Link to comment Share on other sites More sharing options...
Bob Engle Posted January 12, 2018 Share Posted January 12, 2018 Buy a teens Buick and you won't have to worry about front brake adjustment. Use of the pedal brakes and emergency brake at the same time is sometimes needed. Bob Engle 2 1 Link to comment Share on other sites More sharing options...
sportroadster Posted January 13, 2018 Author Share Posted January 13, 2018 Agree, should not complain, at least the rear brakes work, but there is something inside of me that wants everything to function as it is supposed to. To be continued.... Link to comment Share on other sites More sharing options...
Grimy Posted January 13, 2018 Share Posted January 13, 2018 48 minutes ago, sportroadster said: there is something inside of me that wants everything to function as it is supposed to. When all else fails, follow the instructions....in the Buick manual, or an aftermarket brake-specific manual. If you can intuit how to achieve optimum performance without reference to a manual, good on ya. Link to comment Share on other sites More sharing options...
sportroadster Posted January 13, 2018 Author Share Posted January 13, 2018 I followed the instructions in the Buick manual for the right model and year line by line and the result is still not acceptable Then I thought I would go to this forum to get expert and practical input as to how to proceed. Am I missing something Link to comment Share on other sites More sharing options...
Grimy Posted January 13, 2018 Share Posted January 13, 2018 Sorry, I overlooked that you'd done the process according to the manual. Are all the clevises and other "joints" cleaned and freshly lubed? My experience was that years of standing resulted in much friction and no lube in all those many points. Rears: If you have a cross shaft actuated by the pedal is it moving freely? (May have to disconnect pedal rod or rod to rear tor both to determine this.) Clearance if any when brakes fully applied? Fronts: Pull the drums one at a time and have someone operate brake pedal slowly (no cylinders to pop!). With brakes applied, what's the clearance (if any, there shouldn't be) on the shoes? All parts moving freely? Joints clean and lubed, moving freely? By watching the operation while someone pushes the pedal you can spot differences from side to side, and perhaps where someone has mucked around with thr rods, either by bending them or by maladjusting the turnbuckles. Best wishes, and please let us know what you find. Link to comment Share on other sites More sharing options...
raydurr Posted January 13, 2018 Share Posted January 13, 2018 To begin , the factory 1929 Buick manual brake adjustment procedure , even though correct is very confusing. You could adjust through basic reasoning if certain baseline criteria are meet. One overlooked area of easy braking is clevis pins. most are rusty or sticking. Each rod or cable will utilize them. All clevis pins must float freely for optimum results. Return springs in the original places are a must. The brake linings need to be of the exact same material and be the same age. Soft weave is best. Make sure no rods or linkage components have been modified. Each wheel on my 29 has various adjustments to some degree. It is trial and error at some point. I frequently check the brake drum temperature with my hand after each drive. Link to comment Share on other sites More sharing options...
Mark Shaw Posted January 13, 2018 Share Posted January 13, 2018 On 1/11/2018 at 9:47 PM, Grimy said: at full application of brakes they (the levers) are vertical. In my experience, this often overlooked. Sorry to disagree with Gary, but I agree that the levers must be perpendicular to the travel of the rods for maximum leverage. The manual will provide lots of good information about brake to drum clearances but the manual instructions are often not as useful as practical application. I suggest you make sure all the rods and levers are adjusted to the best of your ability and find a dirt or gravel road for testing. Have someone watch as you accelerate and brake hard when you are about to shift into 2nd gear and do as Tinindian instructed: On 1/11/2018 at 1:15 PM, Tinindian said: if part of the system is locking up and part is not that you should back off the one/ones that are locking. Tightening up the ones that don't lock up is the wrong way. Link to comment Share on other sites More sharing options...
Grimy Posted January 13, 2018 Share Posted January 13, 2018 33 minutes ago, Mark Shaw said: In my experience, this often overlooked. Sorry to disagree with Gary, but I agree that the levers must be perpendicular to the travel of the rods for maximum leverage. Mark, since you quoted me, I assume you meant "Grimy" rather than Gary. My example was on a 1925 Pierce, not a Buick, and I certainly agree that the levers need to be as described in the appropriate manual. Actually, in my case, when the Pierce levers are vertical they are indeed perpendicular to the rods so the principle is the same on both makes. Link to comment Share on other sites More sharing options...
Mark Shaw Posted January 13, 2018 Share Posted January 13, 2018 On 1/12/2018 at 1:46 AM, Gary W said: The actuating levers at the wheels MUST not be straight up and down. No Grimy, I don't agree with Gary W. 1 Link to comment Share on other sites More sharing options...
Gary W Posted January 13, 2018 Share Posted January 13, 2018 On 1/11/2018 at 11:23 PM, sportroadster said: Do model A's not use a evener in the brake system? I apologize. I thought he was asking about Model "A" Fords mechanical brake system. And to get the mechanical advantage we set the brake actuating lever 15 degrees forward at the front wheels at rest. At full pull, the levers are pretty much at the top of their travel, perpendicular to the brake rod. I thought he was talking about lever position when you set it up, not the position at full brake. My bad. Link to comment Share on other sites More sharing options...
Mark Shaw Posted January 14, 2018 Share Posted January 14, 2018 Gary, don't feel bad. Just sell that Ford and get another Buick! Wouldn't you really rather have more than one? 1 Link to comment Share on other sites More sharing options...
sportroadster Posted January 22, 2018 Author Share Posted January 22, 2018 Well tackled the first suggestion which was to reduce the friction in the overall braking system I disconnected all the brake rods and levers close to all 4 wheels and also the brake pedal. I now had a brake system where because of the evener in the middle I could independently verify the perceived friction in both the front and rear brake control system Found that I could easily manipulate the rear system with a single finger and barely any pressure, not true for the front. Front took two fingers and firm pressure. After lubricating the swing levers and also backing off the nut on one of the levers most of the friction was removed Front still takes more pressure than the rear but both well in the acceptable range I would think Net result after hooking everything back up was no noticeable difference at the wheels, with car on stands I can lock the rears and the fronts while having resistance can still be easily moved with two hands. So next I think is still adding an additional offset hole to the brake pedal connection on the evener further towards the front wheel side. Pain to get to, and cant get a drill on it so need to figure a way to remove it To be continued... 1 Link to comment Share on other sites More sharing options...
sportroadster Posted January 25, 2018 Author Share Posted January 25, 2018 Finally success, figured out a way to gain access to the evener and was able drill another brake pedal rod position hole The evener is a bar to which the brake pedal, the front brake rod and the rear rod are fastened. the brake pedal is connected in the middle and the front and rears coming from the opposite side on the ends Coming from the factory are 3 positions for the brake pedal rod, dead center and 2 with about a 5% offset on each side of center so allow from more power to one side or another. I was already on 5% more towards the front but that still did not lock fronts, so I drilled a hole about 15% towards the front That gave the front brakes about 65 % of the effort applied by the brake pedal and 35% towards the rears That seemed to do the job as all 4 wheels now lock together, which is defined as car with wheels up in the air and me not being to rotate the wheels by hand Before fronts had some drag but never locked. Of course on the road with 4000 lbs pushing the wheels I don't expect them to lock up So the question still is why did I need that much more effort towards the front with all of the drag in the system removed? Best guess is that the brake band return springs on the front have stiffened over time or that rear return springs have relaxed more than the fronts Who knows but am glad I am back to equilibrium Road test next, as soon as get my windshield from plating and it quits raining. Thanks for all of the help, Will Link to comment Share on other sites More sharing options...
dibarlaw Posted January 25, 2018 Share Posted January 25, 2018 (edited) Will: When I was working on my 1925 master touring there was no front brake action. The pivot was seized and clevis pin pins on the left were pretty sloppy. On the right side the pivot moved but the clevis pins were seized up. Also the return spring was laying in the brake drum broken in 3 pieces. After cleaning, machining oversize clevis pins for the one side then doing all the confusing adjustment sequence. I finally had some brakes on the front. For about 4 wheel spins to adjust while my wife applied the brakes. On the 5th spin I heard the return spring on the left side break. Took the wheels off and put in a bit heavier spring. Now I hope to get to the rear brakes I already know that the left side return spring (on the brake shaft) is broken. Worn clevis pins. Reaming out for an oversized pin. Note the galling of the pivot to the left. All buttoned up with hardly any play. Edited January 25, 2018 by dibarlaw Added content (see edit history) Link to comment Share on other sites More sharing options...
sportroadster Posted January 25, 2018 Author Share Posted January 25, 2018 Thanks for the suggestion, no broken springs so far, but as I mentioned I suspect springs are not performing as they were originally designed How did you figure out what springs to replace them with? Will Link to comment Share on other sites More sharing options...
dibarlaw Posted January 26, 2018 Share Posted January 26, 2018 I bought some from McMaster Carr. They were too light as the springs they showed for the correct type, diameter etc. (1/2 O.D. ) had a smaller wire size. I installed a similar spring with a 5/8" diameter(plenty of room in the drum) because it was a heavier wire gage. Larry Link to comment Share on other sites More sharing options...
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