79Standard
XS650 Addict
Mine has new pads, but is essentially useless. Seems like there is a lot of flex from the rod, also not sure if it's maybe the angle of the arm on the drum that's off.
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Any tips for adjusting rear drum brake?
- Thread starter 79Standard
- Start date
angus67
Welder's penetrate deeper!!
what configuration is your bike? Is it a chop? stock swingarm?
If the rod is flexing, I assume your using it to push the arm, instead of pull the rod.
Pushing the rod can make it fold\collapse. Not a good idea in a 'oh shit' moment.
Now for suggestions.
If the drum is positioned same as stock, the brace rod is at 4 0'clock position, and the arm going into the drum is at 10,11 0'clock. The arm should point down at 7 o'clock for a starting point. If they are new and clean, they will need to bed in, meaning the diameter of the drum to the diameter of the shoes don't match. the shoes need to wear in .
It helps to sand the drum surface were the shoe contacts with a rough grit sand paper. I think I used 80g or there abouts. It doesn't really matter, your just roughing up the surface.
Also sand the pads.
Have the shoes been hit with oil, or anything that can make them slippery? If so, they are no good now. Some cut light grooves at a angle for more bite in the shoes.
Even when it does work, these drums lock up very easy, hence the importance for a front brake.
If the rod is flexing, I assume your using it to push the arm, instead of pull the rod.
Pushing the rod can make it fold\collapse. Not a good idea in a 'oh shit' moment.
Now for suggestions.
If the drum is positioned same as stock, the brace rod is at 4 0'clock position, and the arm going into the drum is at 10,11 0'clock. The arm should point down at 7 o'clock for a starting point. If they are new and clean, they will need to bed in, meaning the diameter of the drum to the diameter of the shoes don't match. the shoes need to wear in .
It helps to sand the drum surface were the shoe contacts with a rough grit sand paper. I think I used 80g or there abouts. It doesn't really matter, your just roughing up the surface.
Also sand the pads.
Have the shoes been hit with oil, or anything that can make them slippery? If so, they are no good now. Some cut light grooves at a angle for more bite in the shoes.
Even when it does work, these drums lock up very easy, hence the importance for a front brake.
Last edited:
Here's some brake shoe threads that may help:
http://www.xs650.com/forum/showthread.php?t=32278
http://www.xs650.com/forum/showthread.php?t=34053
http://www.xs650.com/forum/showthread.php?t=35180
http://www.xs650.com/forum/showthread.php?t=38515
http://www.xs650.com/forum/showthread.php?t=32278
http://www.xs650.com/forum/showthread.php?t=34053
http://www.xs650.com/forum/showthread.php?t=35180
http://www.xs650.com/forum/showthread.php?t=38515
The angle of the brake arm on the drum is kinda dependent on how it all lines up when assembled and adjusted. If you're off a spline tooth or two in either direction, the brake rod will run out of adjustment and stick out way past the rear of the arm, or the arm won't rotate forward enough before engaging the brake to get the adjuster nut on the rod. The usual scenario ends up with the arm at about a 90° angle to the rod and about an inch of rod protruding out the back .....
Your brake rod must be straight. Any bends will greatly reduce the pulling force exerted on the brake arm. In fact, putting a bend in the rod was an old time "fix" for a grabby brake.
Your brake rod must be straight. Any bends will greatly reduce the pulling force exerted on the brake arm. In fact, putting a bend in the rod was an old time "fix" for a grabby brake.
One thing to add, loosen the axle nut. Step on the brake and hold it while you tighten the axle nut. This centers the brake pads in the drum. This way both pads hit the drum at the same time.
Leo
Leo
angus67
Welder's penetrate deeper!!
thanks for that, Leo. does that also help grabby brakes?
Yes, it can.
http://www.xs650.com/forum/showpost.php?p=274197&postcount=7
On those old Harleys, there is also an adjustable post for the brake shoe pivot side, which would need to be loosened, then set by applying the brake (centering the shoes), then both axle nut and pivot post get tightened while pressing the brake pedal.
Not doing that could make the brakes chirpy/grabby, and risks breaking the brake actuator cam...
rainycity
XS650 Addict
"The angle of the brake arm on the drum is kinda dependent on how it all lines up when assembled and adjusted. If you're off a spline tooth or two in either direction, the brake rod will run out of adjustment and stick out way past the rear of the arm, or the arm won't rotate forward enough before engaging the brake to get the adjuster nut on the rod. The usual scenario ends up with the arm at about a 90° angle to the rod and about an inch of rod protruding out the back ....."
Could this also cause the rear brake to not return?
I just went through my back brakes because they wouldnt return hoping that after 35 years they just needed a good cleaning but it didnt help.
The back brake still doesnt return and then what happens is the rod nut backs off because there is no tension on it.
One thing I did notice was that the rectangular shaped pin inside the brake drum was off a few degrees and after looking at 5twins write up and pictorial I noticed his was at 90 degrees.
Any ideas on what may be causing it to not return?
Could this also cause the rear brake to not return?
I just went through my back brakes because they wouldnt return hoping that after 35 years they just needed a good cleaning but it didnt help.
The back brake still doesnt return and then what happens is the rod nut backs off because there is no tension on it.
One thing I did notice was that the rectangular shaped pin inside the brake drum was off a few degrees and after looking at 5twins write up and pictorial I noticed his was at 90 degrees.
Any ideas on what may be causing it to not return?
On the brake plate the shaft the arm hooks onto, goes through the plate. It's flattened on that end. The brake shoes ride on these flats. As you step on the brake the shaft turns and flats push the pads out.
The shaft was greased at the factory. It may not have been greased since. Without grease the shaft can rust. You need to pull the wheel, remove the arm, mark it so it can be put back on in the right place. Remove the shaft, clean it and give it a light coat of grease. There may be shim washers on the shaft. Be sure these go back on the same way.
In the hole the shaft runs through, there is a felt washer. You need to carefully remove this washer and clean and grease it. It acts as a seal and grease reservoir. When you have the shaft and felt washer out clean and grease the hole.
Put everything back in place, the shaft should now spin freely.
Also if the pads are very worn as the shaft turns the pads can ride up far enough that the sit on the ends of the flats. when this happens the pads can't push the shaft back.
Leo
The shaft was greased at the factory. It may not have been greased since. Without grease the shaft can rust. You need to pull the wheel, remove the arm, mark it so it can be put back on in the right place. Remove the shaft, clean it and give it a light coat of grease. There may be shim washers on the shaft. Be sure these go back on the same way.
In the hole the shaft runs through, there is a felt washer. You need to carefully remove this washer and clean and grease it. It acts as a seal and grease reservoir. When you have the shaft and felt washer out clean and grease the hole.
Put everything back in place, the shaft should now spin freely.
Also if the pads are very worn as the shaft turns the pads can ride up far enough that the sit on the ends of the flats. when this happens the pads can't push the shaft back.
Leo
If your "good cleaning" didn't include cleaning and lubing the pivot shaft in the brake plate then it wasn't good enough. Servicing that is about the most important thing during a drum brake renovation.
Disconnect and remove the brake rod from the arm on the brake hub. Work the brake arm by hand. Does it return on it's own? If it does then your problem is farther forward, probably in the pedal pivot. That needs to be kept greased too. There was a grease nipple on the pivot on earlier models to facilitate this but Yamaha eliminated it on later models, most likely as a cost cutting thing. If I owned a later model, I would be searching eBay for an earlier grease nipple equipped pivot to swap in there.
Disconnect and remove the brake rod from the arm on the brake hub. Work the brake arm by hand. Does it return on it's own? If it does then your problem is farther forward, probably in the pedal pivot. That needs to be kept greased too. There was a grease nipple on the pivot on earlier models to facilitate this but Yamaha eliminated it on later models, most likely as a cost cutting thing. If I owned a later model, I would be searching eBay for an earlier grease nipple equipped pivot to swap in there.
rainycity
XS650 Addict
After reading (again) and paying a little better attention which I should have done in the first place, I pulled my rear and took the brakes apart again yesterday.
I ended up having to beat that pin out with a framing axe. I tried a rubber mallet first but it wouldnt do the trick then cleaned it up real good along with the hole, greased it, stuck it back in and the brakes work great now. Thanks again
I ended up having to beat that pin out with a framing axe. I tried a rubber mallet first but it wouldnt do the trick then cleaned it up real good along with the hole, greased it, stuck it back in and the brakes work great now. Thanks again
angus67
Welder's penetrate deeper!!
cool. yes, you don't know until your told.
