How difficult is it to replace the rear drum brakes?

On the years that have a cam plate for the brake warning switch on the shaft, watch how you install it, if it's backwards the brake shoes will hit the hub, hilarity ensues.....
That cam plate soldiered on, even after the switch was discontinued.....
 
Yes, up through '77. With no switch, Yamaha rather crudely hacked the wire bracket off and didn't drill out the switch hole .....

'77 Brake Hub.jpg


In '78, a new cleaner casting came into use .....

'78 Brake Hub.jpg
 
Last edited:
They must have discontinued the brake lining light mid production on the 77. Some of the bikes had the light in the rev counter
 

Attachments

  • 3a 77 gauges.JPG
    3a 77 gauges.JPG
    260.5 KB · Views: 221
A few "before" pics, good example of a how a part that doesn't "look that bad" on the outside can be pretty rough inside. Note; the linings fell off the shoes and were just laying in the hub..

Pics show the fold to remove shoes method, and the cam plate. When removing the pivot shaft, like any stuck part, start with a thin lube, like rust buster. Tap with a hammer and aluminum block to "start movement" add some back and forth using the arm. spray again, tap back in, you want to establish movement and spread the lube to all parts of the shaft and housing BEFORE you attempt to drive the shaft all the way out. This is stuck parts 101, Driving a rusty shaft out of it's bush dry, without lubing and freeing it up first, will cause galling and tear up the softer part, in this case the backing plate bushing, damaging it.

brake cam 001.JPG brake cam 003.JPG

brake cam 004.JPG brake cam 006.JPG
 
Last edited:
Replacing (or servicing) your drum brake (front or rear) is quite simple once you know the one important little trick involved. This is something you should do yourself as opposed to having a shop do it because you will do a better job. There are a couple other items you should address while in there. The pivot shaft that runs through the backing plate should be pulled, cleaned, and greased. Also, the brake drum surface should be cleaned. If you take it to a shop, they'll pop the old shoes off, stick the new one in, and probably won't do any of this other much needed stuff. OK, when you first pull the brake plate out, you'll probably be presented with something that looks like this .....

full


Go to the auto parts store and get yourself a spray can of brake cleaner. You can do a rough cleaning first before you start the disassembly. If you're going to re-use the shoes, mark them "Top" and "Bottom" before removal so they go back in where they came from. Now for the little "trick" - the easiest way to remove/install brake shoes is to "fold" them off and on. Hold one shoe down in it's installed position and simply fold the other one up 90° to it. The shoes will easily come off now as a set still connected by the springs. Install is the reverse - set one shoe down in position (and hold it there), set the other at 90° (and connected with the springs) on the far side of the pivots, and simply fold it down into place. Once the shoes are removed, you can do a thorough cleaning of the backing plate, getting into all the nooks and crannies (Q-tips work well here).

Now on to the other things that need doing. The shoe pivot shaft should be cleaned and lubed. Before removing it, mark the split in the brake arm on the shaft head with a Sharpie. This will allow you to assemble it later with the arm properly positioned .....

full


Once the arm is removed, you should find a felt ring seal nestled down into a depression around the top of the shaft .....

full


Pull the shaft out of the hub noting the position and orientation of the thick washer just under the flats on the brake shoe end. Now you can carefully lift the felt washer out. Clean it by dipping in solvent and pressing between clean paper towels. Repeat until the solvent presses out clean. Knead the clean felt ring full of fresh grease before install. This is the seal for the pivot shaft and is what keeps the dirt and water out.

On the shaft, you'll notice it's center section, the part that resides in the brake plate, is depressed. This is a grease reservoir. After cleaning the shaft and hole in the plate, coat the shaft with fresh grease and work it in and out of the hole to displace the excess lube. Use a twisting motion so the depression remains full. Wipe off all the extra grease that wells up around the top of the hole.

Are you replacing the shoes because you've actually inspected them and found them worn too thin or simply because the brake no longer stops as well as it should? They may be fine and have plenty of life left in them, just needing a thorough cleaning and deglazing, along with the drum. That can be accomplished by lightly sanding the surfaces but by far, the best method is glass beading them. Here's some before and after shots of glass beaded shoes and drums .....

full


full


The springs should be cleaned and if rusty, wire wheeled. Apply a light coat of oil afterwards, just enough so they shine. Before installing the shoes, apply a small amount of grease to the pivot post and the flats on the pivot shaft. After install, wipe away any excess grease that has squeezed out. The finished job should look something like this. Note the small amount of red grease showing at the edges of the flats on the pivot shaft (excess having been wiped away). And yes, this is the same brake plate assembly from the first pic after cleaning .....

full


Edit 3/21/19 - Through careful research and measuring, member 2M has discovered that the brake cam is not exactly symmetrical. One end of the cam moves or applies it's brake shoe slightly less than the other end. The splined end of the cam has a dimple stamped in it. This denotes the end of the cam that applies it's shoe slightly less. The cam should be installed with the dimple on the inboard side, towards the axle .....

arKDkY2.jpg


All the details on this can be found here, starting with post #29 .....

http://www.xs650.com/threads/650-rear-drum-brake-plates.51046/page-2

This is such a good thread as I am going to tackle this on my bike. Newbie question - how do I know if the brake shoes need replacing? I plan on cleaning and even media blasting them if need be. But how can I tell?
 
Usually you can tell by how thick the remaining lining is on the shoes. I don't have a measurement for them but could probably measure some good and badly worn ones to see. But, from the looks of and the issues you're having with your wheel in that other thread, I don't think worn shoes will be your issue. You'll probably find them falling apart, the lining coming unglued from the shoe. That's how I've found them usually in badly corroded up hubs like yours.
 
Usually you can tell by how thick the remaining lining is on the shoes. I don't have a measurement for them but could probably measure some good and badly worn ones to see. But, from the looks of and the issues you're having with your wheel in that other thread, I don't think worn shoes will be your issue. You'll probably find them falling apart, the lining coming unglued from the shoe. That's how I've found them usually in badly corroded up hubs like yours.

Perfect thanks for clarifying. As I tackle this in upcoming days I am sure to ask you more questions. I saw on Mike's they sell xs/tx650 shoes for relatively good price.
 
Yes, but they won't fit in your TX750 wheel, you need different ones. Yours are 20mm bigger in diameter and 10mm wider .....

full


full


This bigger, better rear brake is one of the things that makes the TX750 wheel such a nice "upgrade".
 
Vesrah is just one of the aftermarket brands available. There are others like EBC and Ferodo. I'd say get whatever you find the best price on.

You should be able to salvage the other internal parts like the shoe springs and the brake arm pivot.
 
Vesrah is just one of the aftermarket brands available. There are others like EBC and Ferodo. I'd say get whatever you find the best price on.

If you know the model numbers EBC and Ferodo? Quick search shows Vesrah approx $50 for me

You should be able to salvage the other internal parts like the shoe springs and the brake arm pivot.
 

Attachments

  • IMG_20191108_134328.jpg
    IMG_20191108_134328.jpg
    216.9 KB · Views: 153

Attachments

  • IMG_20191108_140158.jpg
    IMG_20191108_140158.jpg
    265.6 KB · Views: 157
  • IMG_20191108_140400.jpg
    IMG_20191108_140400.jpg
    167.5 KB · Views: 189
Maybe installing the axle back through the backing plate and wheel would help keep it all aligned for pulling that darn stuck backing plate off.


That's a good idea but these are the extra set of wheels I have for my bike. The bike has the Alloy wheels on them right now so I can't put back onto axel
 
I just checked two sets that are out of the hubs, an '81 and an earlier model with the brake wear light setup. The only thing that makes sense in your situation is that the shoes are seized inside the drum somehow. Corrosion? Busted spring jamming up the works? Oval pivot turned and corroded in place?
The splined shaft is what pivots and spreads the shoes to stop. I'd be lubing the perimeter of the hub trying to get it into the shoes.....forget about reusing....and lubing around the splined shaft. Then prying ever so gently on the plate where the splined shaft is closest to the outside edge of the hub while tapping the splined shaft with a rubber mallet.
Other opinions may vary.....not responsible for damage or injury.....lol.
 
I just checked two sets that are out of the hubs, an '81 and an earlier model with the brake wear light setup. The only thing that makes sense in your situation is that the shoes are seized inside the drum somehow. Corrosion? Busted spring jamming up the works? Oval pivot turned and corroded in place?
The splined shaft is what pivots and spreads the shoes to stop. I'd be lubing the perimeter of the hub trying to get it into the shoes.....forget about reusing....and lubing around the splined shaft. Then prying ever so gently on the plate where the splined shaft is closest to the outside edge of the hub while tapping the splined shaft with a rubber mallet.
Other opinions may vary.....not responsible for damage or injury.....lol.

Thanks. Yes corrosion is for sure and the shoes do look stuck to the drum. I will keep at it... I want to resuse the wheel at some point after cleaning it up
 
Back
Top