D21 brakes
Printed From: Unofficial Allis
Category: Allis Chalmers
Forum Name: Farm Equipment
Forum Description: everything about Allis-Chalmers farm equipment
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=210637
Printed Date: 07 Apr 2026 at 1:13pm
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: D21 brakes
Posted By: whatscooking
Subject: D21 brakes
Date Posted: 04 Apr 2026 at 6:17pm
| Are the drums interchangeable side to side? |
Replies:
Posted By: DrAllis
Date Posted: 04 Apr 2026 at 6:19pm
| Yes. Install so the drums splines are closest to the end of the bull pinion shaft. |
Posted By: whatscooking
Date Posted: 04 Apr 2026 at 6:28pm
| Took one side off. Curious how the balls work? Is it advisable to scuff up the drum and both sides for the disc? |
Posted By: whatscooking
Date Posted: 04 Apr 2026 at 6:31pm
| I just went in for a look and tried grinding and sanding and blew it out. Splins and drum look servicable. Didn't seem to help with stopping.About decided to send to Rick to reline everything. |
Posted By: DrAllis
Date Posted: 04 Apr 2026 at 6:44pm
| Just know that even when the brakes are working great on a D-21, you may sometimes feel like Fred Flintstone trying to stop his car. They are just borderline OK (at best) and even worse with duals, and the heavier the tractor is the less effective they are. I always lightly grease the ball pockets so they don't rust and the balls can freely roll. I also lightly grease the splines and install the drum on/off in several different locations to spread the grease film around. Wipe off any excess grease. For those who are so damn sure you shouldn't grease/lube anything because of a dirt environment, keep it to yourself. I oil gathering chains on a corn head and they are in dirt all the time too. |
Posted By: tbran
Date Posted: 04 Apr 2026 at 8:25pm
|
To your question as to how the balls work, and I am assuming you mean the balls in the brake assy, it is like this. The balls are inside two sockets that have ramps in each direction radially. Springs hold them two brake halves together. When one depresses the brake pedal, the outer bang closes around the drum half that is not splined to the pinion and tries to stop it. As it now moves slower than the splined half, it rotates slightly and the balls in question start to ride up the ramps. This forces the two halves apart slightly and causes the inner and outer brake linings to contact the outer and inner steel housings. The more pressure applied to the bands vial brake pedal the more self energizing the side pressure becomes as now the non- splined half is assisted by the braking action and forces the balls up the ramps even more. This is the reason when the two springs that hold the two halves together break or the ramps break, the brake continues to self energize and locks the wheel down and can only be released by backing up - unless it explodes and pieces either make for no brake or a complete lock up. Scuffing up the metal should not be excessive, the issue is the brake material glazes over - scuffing them up is more beneficial if there is enough pad left. ------------- When told "it's not the money,it's the principle", remember, it's always the money.. |
Posted By: whatscooking
Date Posted: 05 Apr 2026 at 5:20am
| This info really helps. Any suggestions where to purchase the linings and what type of rivet tool? |
Posted By: whatscooking
Date Posted: 05 Apr 2026 at 7:00am
I have worked alot figuring out what is the best type of antisize/lube that really works. I cringe when I see the silver stuff, it should be called sure to sieze. Hear me out or flame me doesn't matter whether on king pins,tie rods any where or just about everywhere I have had remarkable results using CRC DIELECTRIC, the stuff for coating electrical connections, dont use it there, cuases resistance. |
DrAllis wrote:Posted By: DrAllis
Date Posted: 05 Apr 2026 at 7:23am
| The original brake band and disc linings from 35+ years ago were made out of asbestos of some kind. The band/disc brake combo was designed and built by the Bendix corporation. This style of brake was used on other machines besides A-C. Any replacement linings I have used in the last 35 years just don't seem to have the stopping power of the originals. Rick Corder posts on here occasionally and can fix you up I think. |
Posted By: wjohn
Date Posted: 05 Apr 2026 at 7:41am
Always something to keep in mind if scuffing up old bands/linings (keep that dust out of your lungs)! ------------- 1939 B, 1940 B, 1941 WC, 1951 WD, 1952 CA, 1956 WD-45 |
Posted By: ranger43
Date Posted: 05 Apr 2026 at 8:33am
| Close to 30 years ago I had my 210 brake discs relined with Kevlar from SouthBend Clutch in Indiana. I have the tractor weighted, radial duals and plant beans with it. About 1200 hours on the discs. I had to pull one side to due to a broken spring, the discs had very little wear. |
Posted By: whatscooking
Date Posted: 06 Apr 2026 at 7:35am
|
Called them this morning and they said they quit that 15 years ago. When I changed clutches in BBT awhile back I had Powerstrokes T444 and Cummins 6B that had a Spicer 5 speed. The flywheel, well both sides, we're ate up and had to resurface the flywheel, usally only once. Then we started getting a Luke kit that had the flywheel side Kevlar. Next clutch job you could still see the machine marks from being ground. Saved me alot of work. |
Posted By: SteveM C/IL
Date Posted: 06 Apr 2026 at 7:42am
| try Tribco Inc Cleveland Ohio. Looks like current business on internet. Someone on here used them years ago for a 220....that's why I bookmarked it. |