XJ 650 Rear Brake

[wingnut]

Seems to be a rash of this happining with the XJ 650s. Happened to me yesterday. After a 200 mile ride I parked it in the driveway. Came back to push it in the garage and it pushed very hard. Pulled the rear wheel and found this.

[randy]

That's one reason why the maintenance manuals call for regular service intervals. That hub looks like it hasn't been opened in 10 years.

[wingnut]

This is the second one of these that I've seen. Both bikes had been sitting for quite a while. One out side one always inside. This one has 13K on the clock and the bike is in near perfect condition. The other one had 28K on it and was a resurrection from the dead. I agree regular inspection is the answer. The hub shown isn't as bad as it looks in the picture. A quick once over with a brush and its now clean and shiny. While I'm in here the bearings and splines get a once over.

[daveyg]

So what's wrong? Did the pad material fall off of the shoe? Did you just have to clean it up and reassemble with new pads? Thanks for the pointers.

[wingnut]

Yes the pad abrasive material just delaminated from the shoe. It looks like moisture seeps thru the material and sets up some corrosion on the soft aluminum shoe. The adhesive looses its grip on the shoe side and it comes apart when you put it under shear pressure when braking. Be really bad if that happened at speed and the rear locked up on you, Ordered new shoes. I did repair one of these a couple of years ago on another bike by wire brushing both surfaces, cleaning them up with acetone and buttering the shoe with JB wield. Clamped it together and let it sit for 24 hours. Worked great. I tried real hard to make it brake loose but not matter how hot I got it it held up. That bike is gone now but last I head that repaired pad had about 8 K mile on it before the owner replaced it. I do not recommend that as a repair but I was stuck for parts at the time. I guess the JB wield is a better adhesive than what the factory used.

[daveyg]

Hm... Nice fix idea... To be used with caution though of course. Yeah, I'd be ready to kill someone at the local Yamaha shop if I was blasting down the freeway at 110 and the dammn rear wheel locked up... That is, If I wasn't already dead. Any idea what mileage is good to replace the rear brake shoes? My bike is darn near 20k, and I have no records of past maintenance.

[cywelchjr]

Hm... Nice fix idea... To be used with caution though of course. Yeah, I'd be ready to kill someone at the local Yamaha shop if I was blasting down the freeway at 110 and the dammn rear wheel locked up... That is, If I wasn't already dead. Any idea what mileage is good to replace the rear brake shoes? My bike is darn near 20k, and I have no records of past maintenance.

I would suggest replacement with new. I had mine delaminate after sitting for 13 years, cleaned it up and replaced the shoes and it's all good now. Won't let it sit that long again, and it's a good idea to keep them dry as it does seem to be corrosion from moisture that causes the problem.

[daveyg]

Well mine has never sat for more than a year at any given time during it's life, and has been garaged most of it's existence too so, does that mean I'm safe? Or should I rip the rear apart just to be safe? Will the XS11 rim fit in the XJ650 swingarm? Will the drive line up? Cuz I could sure fab up a caliper mount and make this baby rear disk... That is if the drive will work.

[wingnut]

I would think the general practice is to inspect the shoes during a tire change or when other maintenance drives removal of the rear wheel. That being said I don't think you can tell when the adhesive is going to fail by looking at the shoes or by the mileage on the machine. I do think that if the bike sits for an extended time and if they ever stick to the drum from corrosion, then enough moisture has gotten in there to cause a problem. On both of my experiences with delaminating shoes I found evidence that the shoes had stuck to the drum at some time. Looks like pitting and rust on the drum surface. If I see that I'm going to replace those shoes. If you have OEM parts still in the bike after 25 years it just might be a good idea to go ahead and spring for the new parts just for the peace of mind. The replacement takes about 10 minutes once you have the wheel off. I just bought a new set from JCWhitny. $48 delivered in 3 days and the kit came with new springs. Item 273868 EBC BRAKE SHOES 512. OEM from Bike bandit was about twice that.

Don't think the 1100 wheel will fit up, I've never tried but the finial drive is different and the splines look smaller.

[daveyg]

Well I could use a new rear tire... Maybe once I get the 11's rear off I'll take the 650 off to compare. I really would like having the 11's brakes on my 650... But if it don't work out... I'll just buy the shoes/pads and replace.