|
Sponsored Links (Register now to hide all advertisements) |
|
|
Thread Tools | Display Modes |
05-21-2017, 09:11 PM | #1 |
BANNED
Join Date: Apr 2017
Location: Lower Left Coast
Posts: 469
|
Angle of Brake Arms
After reading waaaaay too many postings on brake adjustment, and the Service Bulletin Nov 1928 pg. 298, 299, 300, I am a bit confused.
From all the postings and advice I have determined that the Front arms need to be set at a 15° angle, but I am not sure what the rear brake arm angle is to be before adjusting the rods to length. According to the Service Bulletin, it says nothing about a starting angle of the arms before starting the brake rod adjustment. While I am at it, what about the E-brake arms? Thanks. |
05-21-2017, 10:25 PM | #2 |
Senior Member
Join Date: Apr 2015
Location: Boise, Idaho
Posts: 1,578
|
Re: Angle of Brake Arms
On the rear brakes and e-brake you just take up the slack and then adjust the clevis yoke so the pin just slips into place...it's tough to tell when the slack is taken up if the anti-rattlers are in place.....I set mine initially with the drums off so I could see when the shoes and band started to move...
At least that is what I have read.
__________________
Early '29 CCPU that had a 4-speed, but not any more.......in the family since '62 |
Sponsored Links (Register now to hide all advertisements) |
|
05-21-2017, 11:35 PM | #3 |
Senior Member
Join Date: Mar 2016
Location: Lynden, WA
Posts: 1,564
|
Re: Angle of Brake Arms
I am close to diving in on my brake adjustments as well. I got them set so they work pretty good, getting a few miles on them first. I easily have 15 degrees on the fronts, I adjusted up the back rods until they just started to pull hard. I'm waiting for a day that I can spend going through the procedure.
|
05-21-2017, 11:53 PM | #4 |
BANNED
Join Date: Apr 2017
Location: Lower Left Coast
Posts: 469
|
Re: Angle of Brake Arms
OK, FWIW.
I have read and read and since I am not into working with wood, this is how I think I will approach this. First, get all the brakes installed and the service brake arms set at 15°, front and back and the cross bar set so it can NOT return to hit the cross member with the pedal returned to top position, since the rod from pedal to cross bar is adjustable too. Now, since Randy Gross doesn't install brakes, he has no thoughts on hos to adjust them. So, I will bring the adjusters up until the brakes lock the wheel from turning, then back off 2 clicks or until the wheel rolls free, no more than 3 clicks. I really think this should work since I do NOT want the rear to lock up before the fronts, but have equal braking on all wheels. If I find, after driving and braking, from easy to hard, that one wheel works harder or heats up, readjust to get all wheels doing the same work. But as a starting point, just lock up, and back off to turn freely.
__________________
Before Walmart you had to buy a ticket to the fair to see a bearded lady! |
05-22-2017, 12:24 AM | #5 | |
Senior Member
|
Re: Angle of Brake Arms
Quote:
__________________
What's right about America is that although we have a mess of problems, we have great capacity - intellect and resources - to do some thing about them. - Henry Ford II |
|
05-22-2017, 12:36 AM | #6 |
BANNED
Join Date: Apr 2017
Location: Lower Left Coast
Posts: 469
|
Re: Angle of Brake Arms
Sponsored Links (Register now to hide all advertisements)
Ok, so you are saying that when I have the cross shaft and rod correct, I should wind up with a 15° angle at the beginning of the brake shoe movement? This sounds possibly wrong. Not to argue. The way I read the Service Bulletins and forum postings, the angle should be the relaxed setting on the wheel brake to "start the braking process". With this it gives the cross shaft 15° travel and pedal enough travel to lock up all the brakes without bottoming out or running out of pedal. Now, I could be wrong, but this is how I read it.
__________________
Before Walmart you had to buy a ticket to the fair to see a bearded lady! |
05-22-2017, 09:02 AM | #7 |
Senior Member
Join Date: Apr 2015
Location: Boise, Idaho
Posts: 1,578
|
Re: Angle of Brake Arms
When you get the front brakes apart i think you will see that Mike is correct.
With the original operating wedge and operating pin the cam on the actuating arm will not even begin to move the operating pin until the lever is near 15° or even vertical... The "pills" that fit into the wedge help you set this angle by effectively adding length to the operating pin
__________________
Early '29 CCPU that had a 4-speed, but not any more.......in the family since '62 Last edited by 1955cj5; 05-22-2017 at 09:15 AM. |
05-22-2017, 09:32 AM | #8 |
Senior Member
Join Date: May 2010
Location: Young Harris, GA
Posts: 1,821
|
Re: Angle of Brake Arms
Mike is absolutely correct. The wedge must be actually operating the shoes, all slack out, when the arm is still tipped forward 15*. The solution is to lengthen the operating pin.
I really don't like the pills. They are too coarse of an adjustment. "1 is not enough, 2 is too much" sort of thing. Also, they put the pin end up pretty high in the wedge hole. I'd hate for that pin to somehow jump out! It is better to weld up the end of the pins to get the desired angle of the arm. Weld up and then grind down to a nice round ball ends. Then the pin sits deep in the hole on top of the wedge, as Henry designed it. YMMV.
__________________
Jim Cannon Former MAFCA Technical Director "Have a Model A day!" |
05-22-2017, 10:23 AM | #9 | |
Senior Member
Join Date: Jul 2011
Location: Redondo Beach, CA
Posts: 5,849
|
Re: Angle of Brake Arms
Quote:
Make sure your operating pins are not worn also. I just installed new ones from Bratton's and was able to use just one thin shim. Mike is right, on the front with all free play out the angle should be ~15° toward the front of the car. Last edited by Y-Blockhead; 05-22-2017 at 10:39 AM. |
|
05-22-2017, 10:34 AM | #10 |
Senior Member
Join Date: Jun 2010
Location: Polk City, Iowa
Posts: 526
|
Re: Angle of Brake Arms
I needed 2 pills on one of my brakes. Did not want to put 2 pills on the bottom for the reason expressed in post #8. I put one on the bottom of the pin and one on the top of the pin. Seemed to work for me. I don't know what some of you experts think of this but I am willing to learn. Maybe this was a bad idea.
__________________
Steve Hanna, Polk City, IA |
05-22-2017, 10:43 AM | #11 |
Senior Member
Join Date: May 2010
Location: Mpls, MN
Posts: 27,582
|
Re: Angle of Brake Arms
I'd just replace the push rods if they are worn.
2 new rods put the levers where they should be on one I worked over. |
05-22-2017, 11:14 AM | #12 |
Senior Member
Join Date: Jul 2011
Location: Redondo Beach, CA
Posts: 5,849
|
Re: Angle of Brake Arms
They're actually pretty cheap@ $2.15 ea., aren't they? https://www.brattons.com/front-brake-operating-pin.html Considering 4 shims will put you back $1.90.
|
05-22-2017, 11:26 AM | #13 | |
Senior Member
Join Date: May 2010
Location: Central, IL
Posts: 3,968
|
Re: Angle of Brake Arms
Quote:
__________________
1929 Model AA - Need long splash aprons! |
|
05-22-2017, 02:43 PM | #14 |
Senior Member
Join Date: Jul 2011
Location: Redondo Beach, CA
Posts: 5,849
|
Re: Angle of Brake Arms
Haha, I can relate to that! But if all the free play is adjusted out and everything lubed up nicely, there shouldn't be too much Jack Hammerin' going on.
|
05-22-2017, 03:37 PM | #15 |
BANNED
Join Date: Feb 2013
Location: Coatesville, Pa
Posts: 719
|
Re: Angle of Brake Arms
Seems to me the critical angle is not the 15* but the angle when the brake is on real hard. It should be 90* to the brake rod there by giving maximum leverage. JMO.
|
05-22-2017, 04:32 PM | #16 | |
Senior Member
Join Date: May 2010
Location: Largo Florida
Posts: 7,225
|
Re: Angle of Brake Arms
Quote:
Thats correct. Beyond 90/0º leverage is lost. The 15º spec is good to keep the arm within the 'leverage' range. |
|
05-22-2017, 04:35 PM | #17 |
Senior Member
Join Date: May 2010
Location: Largo Florida
Posts: 7,225
|
Re: Angle of Brake Arms
This brake system is non-energizing. The rear brakes should lock just before the fronts.
The service bulletins says how they should be adjusted. I'm a fan of a brake adjustment board however. |
05-22-2017, 06:00 PM | #18 |
Senior Member
Join Date: Mar 2015
Location: Greenville, SC
Posts: 1,099
|
Re: Angle of Brake Arms
After getting everything set according to the book and "feel" would fine tuning with an infrared temp sensor be of any benefit?
John |
05-22-2017, 06:06 PM | #19 |
BANNED
Join Date: Feb 2013
Location: Coatesville, Pa
Posts: 719
|
Re: Angle of Brake Arms
I only use the temp sensor to check to see if any brake is dragging. Not much use for fine tuning.
|
05-22-2017, 07:51 PM | #20 |
Senior Member
Join Date: May 2010
Location: Largo Florida
Posts: 7,225
|
Re: Angle of Brake Arms
You could use your temp gun if you like, probably wouldn't hurt anything.
I think a dragging brake can be felt, heard when spinning the wheels or even rolling the car. I 'fine tune' the brakes just by testing them. I don't want it to shuck or jive and I like both rears to lock at the same time and both fronts to drag and lock slightly after the rears and stop the same. I adjust till they do. But, maybe thats just me. |
|
|
Sponsored Links (Register now to hide all advertisements) |
|