82 XJ1100 rear brake caliper drag

[HalfCentury]

I rebuilt all three brake calipers on the XJ1100. The front wheel spins beautifully with no brake pad drag. The front brake lever grabs well with great stopping power. I install a stainless steel line on the front right.

The rear wheel does not spin effortlessly. There is a noticeable drag on the brake rotor with the bike on the center stand spinning the rear wheel by hand.

I have read about a shimming a non-floating caliper to correct this problem. Has anyone done this successfully?

[DiverRay]

If the caliper is not centered in the brake, you probably have the wrong parts installed on the axle/wheel assembly. The ONLY time I've had problems is when I switch a special rear rim and a standard. The spacers on the axle are different, so I would start there.
If the brake pads are dragging, then the seal in the caliper is the cause. If that is the case, remove the seal and CLEAN the grove it sets in. The piston should go in and out by hand.

[HalfCentury]

Hello Ray

Thank you for the thoughtful reply. When I disassembled the caliper, I scrupulously cleaned the caliper and piston inside and out. I used a brass brush in a Dremel to remove every speck of vulcanized rubber that was in groove. I inspected the groove with a large magnifier in bright sunlight.

The piston moved easily in and out of the cylinder before reassembly.

The reason for my initial question is that the brake pads are slanted when viewed edge-on so obviously the caliper does not sit exactly parallel to the rotor. The caliper does not float the way the front calipers do so if there is some misalignment, it is not self correcting the way the front calipers are.

If the caliper is not centered in the brake, you probably have the wrong parts installed on the axle/wheel assembly. The ONLY time I've had problems is when I switch a special rear rim and a standard. The spacers on the axle are different, so I would start there.
If the brake pads are dragging, then the seal in the caliper is the cause. If that is the case, remove the seal and CLEAN the grove it sets in. The piston should go in and out by hand.

[TopCatGr58]

Hey there,

You cleaned the calipers, but sounds like you may need to work on the master cylinder. The Xj's is special because it has a proportioning valve and such since the rear MC feeds both the rear caliper and the left front one.
I know there's a spooge hole for the front MC, there should also be one or more for the rear MC as well.

Another thing, did you check out the mounting bolt for the rear caliper to make sure that it's straight, and not bent. Yamaha used the same type of caliper for their specials on the front wheels. Why they put the same type on the rear of the Maxim, I don't know? But special owners have reported pulsing on the front ones and found that their bolts were bent. Once they put new straight ones on, the pulsing went away. JAT!

Also, with the fronts, there are left side and right side pairs, the slants are opposite for each side. No aspersions intended, just asking that you're sure you put the correct side/slanted pads on for the rear?

T.C.

[HalfCentury]

Hi Top Cat

I did not know about the bent bolts. My recollection is that there was no problem installing the long mounting bolt that goes through the caliper. I can certainly remove the bolt and check it against a T-square for trueness.

I am sure the rear pads are installed correctly. The shiny shim goes against the caliper piston. I do not think that you can install the rear pads any way but correctly since the mounting pin goes through the end of the pads. The front pads are mounted through the center which could conceivably

I rebuilt the front MC but not the rear MC. I did flush the rear MC and lines with fresh fluid. There was no gunk in the rear MC and the fluid looked clean unlike the front MC which was caked with brown goo and the front calipers were seized.

The rear MC is slated for rebuild when I replace the remaining lines with stainless steel lines. That will also be when I check the valve clearances this winter.

Hey there,

You cleaned the calipers, but sounds like you may need to work on the master cylinder. The Xj's is special because it has a proportioning valve and such since the rear MC feeds both the rear caliper and the left front one.
I know there's a spooge hole for the front MC, there should also be one or more for the rear MC as well.

Another thing, did you check out the mounting bolt for the rear caliper to make sure that it's straight, and not bent. Yamaha used the same type of caliper for their specials on the front wheels. Why they put the same type on the rear of the Maxim, I don't know? But special owners have reported pulsing on the front ones and found that their bolts were bent. Once they put new straight ones on, the pulsing went away. JAT!

Also, with the fronts, there are left side and right side pairs, the slants are opposite for each side. No aspersions intended, just asking that you're sure you put the correct side/slanted pads on for the rear?

T.C.

[TopCatGr58]

Hey again,

Here's an excerpt from the tech tip:

Yes, this taper is normal! This Special front and LH/XJ rear set is near new; if they're worn, the taper will be less. These pads are side specific; there's a left and right side. Looking from the end with the hole for the retaining pin, this is a right side set; the left side will be tapered opposite. The two 'tabs' you see in the middle of the backing plates are the wear indicators; if these get close to or touch the rotor, time to replace.

What I was talking about was possibly getting the wrong side pair of slanted pads....not turning the old ones around somehow. In the above photo, the slant goes upper left to lower right, but the other side goes from upper right to lower left, that's all.

As to the mounting bolt, don't forget to apply some brake grease to let the caliper swivel easier around the bolt/shaft. And you can just roll it across a flat surface, if wobbles, replace. A little pad drag is normal though. Take a short ride, a few minutes and then come to a stop using just the front brake(XJ just the handlebar lever), and then get off and feel the rear rotor, it can be warm to touch, but you should be able to grab/hold it without burning your fingers. If it's too hot, then yes, there's too much drag.
Otherwise, it's okay and don't worry about it. The rear wheel doesn't spin freely like the front wheel due to the driveshaft/final drive drag.

T.C.

[HalfCentury]

Hello Top Cat

Thanks for the additional info. This is pretty much all new to me. Now it makes sense that the final drive adds drag to the rear wheel.

I will try the warm-to-touch test next time I have it out for a spin.

I will inspect the handedness of the pads when I change the brake lines. I will also make sure the bolt is greased for easy rotation. Thanks for the tips. I will have a close look at the tech tips.

Hey again,

Here's an excerpt from the tech tip:



What I was talking about was possibly getting the wrong side pair of slanted pads....not turning the old ones around somehow. In the above photo, the slant goes upper left to lower right, but the other side goes from upper right to lower left, that's all.

As to the mounting bolt, don't forget to apply some brake grease to let the caliper swivel easier around the bolt/shaft. And you can just roll it across a flat surface, if wobbles, replace. A little pad drag is normal though. Take a short ride, a few minutes and then come to a stop using just the front brake(XJ just the handlebar lever), and then get off and feel the rear rotor, it can be warm to touch, but you should be able to grab/hold it without burning your fingers. If it's too hot, then yes, there's too much drag.
Otherwise, it's okay and don't worry about it. The rear wheel doesn't spin freely like the front wheel due to the driveshaft/final drive drag.

T.C.

[Ken Talbot]

Hello Ray

The reason for my initial question is that the brake pads are slanted when viewed edge-on so obviously the caliper does not sit exactly parallel to the rotor. The caliper does not float the way the front calipers do so if there is some misalignment, it is not self correcting the way the front calipers are.

Hold on a minute. If you are talking about the rear brakes, and you are saying that the pads are "slanted when viewed edge-on". This tells me you are trying to install pads meant for the front brakes, which are quite different from the pads for the rear brake.

The rear caliper does not float like the front ones, but it does move side to side. Its pads should not look slanted from any direction.

[HalfCentury]

The XJ1100 rear brake is almost identical to the XJ650 front brake except for pointing in opposite directions. Both use a slanted brake pad that is cantilevered at one end as opposed to the front pads which are cantilevered in the middle.


QUOTE=Ken Talbot;477363]Hold on a minute. If you are talking about the rear brakes, and you are saying that the pads are "slanted when viewed edge-on". This tells me you are trying to install pads meant for the front brakes, which are quite different from the pads for the rear brake.

The rear caliper does not float like the front ones, but it does move side to side. Its pads should not look slanted from any direction.[/QUOTE]

[crazy steve]

Hold on a minute. If you are talking about the rear brakes, and you are saying that the pads are "slanted when viewed edge-on". This tells me you are trying to install pads meant for the front brakes, which are quite different from the pads for the rear brake.

The rear caliper does not float like the front ones, but it does move side to side. Its pads should not look slanted from any direction.

Ken, the XJ uses a 'Special front' type caliper in the rear (same casting, just machined different), so the slanted pads are correct.

A bent bolt on the XJ rear is not very common, as it uses a larger bolt for mounting, although it would still pay to check. Brake drag would be more likely from a binding caliper sleeve (the sleeve in the caliper that the bolt goes through) as the caliper actually pivots on the sleeve, not the bolt. You also need to make sure you have the right washers in the right places, as well as the stainless steel pad contacts installed on the caliper mount. More detail here: http://www.xs11.com/forum/showthread.php?t=37207

Detail on the pads/retainers.... http://www.xs11.com/forum/showthread.php?t=37206

And as was mentioned, there's considerable driveline drag (final drive, middle drive, trans), so the rear wheel will never spin as freely as a front.

[HalfCentury]

Hi Steve

Great thread about the rear caliper. Thanks for the link. I have a question. Should the caliper be free to rotate about the long bolt? Is there a torque specification for tightening the long bolt?

When I rebuilt the caliper, I removed the caliper but not the mounting bracket. I used a brass Dremel brush to thoroughly remove all dirt/rust/crud from the sleeve, bolt and caliper. Everything fits and slides effortlessly. Every part of the caliper and all of the hardware are squeaky clean. I went out to the garage just now and ran a finger over the caliper. Everything remains squeaky clean. I did not use any grease on the bolt or sleeve. If needed, I can disassemble enough to apply some grease.

Ken, the XJ uses a 'Special front' type caliper in the rear (same casting, just machined different), so the slanted pads are correct.

A bent bolt on the XJ rear is not very common, as it uses a larger bolt for mounting, although it would still pay to check. Brake drag would be more likely from a binding caliper sleeve (the sleeve in the caliper that the bolt goes through) as the caliper actually pivots on the sleeve, not the bolt. You also need to make sure you have the right washers in the right places, as well as the stainless steel pad contacts installed on the caliper mount. More detail here: http://www.xs11.com/forum/showthread.php?t=37207

Detail on the pads/retainers.... http://www.xs11.com/forum/showthread.php?t=37206

And as was mentioned, there's considerable driveline drag (final drive, middle drive, trans), so the rear wheel will never spin as freely as a front.

[trbig]

Is there a chance you may have installed the clip (on the rear mounting pin that goes through the pads) up against the pads instead of over against the caliper? This would make them not be able to retract fully. And yes, the rear wheel with the drivetrain spinning as well will never spin freely like the front does. Even a quick mile ride,using only the front brake, and feel the disc will tell you if the brakes are dragging. One suggestion though... make the first touch as quick as possible. I hate the sound of sizzling flesh when it's my own.

[HalfCentury]

Here is the caliper from rear. I remember figuring out that the spring clip has to be right up against the caliper to prevent the pin from moving.

Is there a chance you may have installed the clip (on the rear mounting pin that goes through the pads) up against the pads instead of over against the caliper? This would make them not be able to retract fully. And yes, the rear wheel with the drivetrain spinning as well will never spin freely like the front does. Even a quick mile ride,using only the front brake, and feel the disc will tell you if the brakes are dragging. One suggestion though... make the first touch as quick as possible. I hate the sound of sizzling flesh when it's my own.

[Ken Talbot]

Ken, the XJ uses a 'Special front' type caliper in the rear (same casting, just machined different), so the slanted pads are correct...

Oops - I think I may have been reminded about that before...

[SFerinTEXAS]

You know in that last pic it appears the torque plate is pinched in front of the axle bolt shoulder .It should ride on it .