Rear Rotor Issue

[Bill]

While in the process of changing tires yesterday, I did the front first, installed Ride-On sealant and took the bike for a 20 mile ride to see if I needed to add weights.

However.... I noticed that the rear brake didn't feel quite right. Actually, it didn't seem like the rear pads were working at 100% and I couldn't press on the pedal hard enough to lock the brake or even engage the ABS.

When I got the bike back home, I noticed that the rear wheel wouldn't turn freely for all 360 degrees. Instead, the brake pads dragged against one quarter of the rotor surface. After removing the caliper, I turned the wheel and couldn't really notice any warping but the rotor looks slightly scorched in that section and on both sides.

Damn....

In about two weeks, I'm planning to do the SMCA Four Corners Tour and found out that the rear rotors are on back-order until September 24th.

I can get a new Galfer Wave Rotor and new brake pads in time to make the trip but should the OEM rotor actually be replaced or, did it just overheat from a stuck brake pedal?

Thanks

 

[ionbeam]

You wouldn't be the first to have an assembly problem. Double check your wheel install and be sure that the washer is installed correctly. Did the indexing tab go into the slot on the ABS sensor housing? Does your rear wheel turn properly and the brake feel normal after removing the caliper to inspect things? It happens every now and again for the brake pads to both end up together on one side of the rotor. The caliper torque rod is assembled correctly (with the hardware)? Hey, just trying to find a simple, inexpensive problem for ya.

It takes a lot to warp a rotor in 20 miles without noticing a burning brake smell. You can take a pencil, dowel, or any not metallic rod and put the end against the rotor then using your hand like a clamp hold the poor man's dial indicator against the rotor and spin the wheel. If the rotor has any significant warping you will feel it.

 

[SkooterG]

When changing the tire, did you put pressure on the rotor and warp it? None of these symptoms were present before the tire change? If so, I would say you screwed something up.

How much is it 'grabbing' in that one area? It's not unusual to have a little bit of that.

You really need a dial indicator to check the rotor.

I recently had a rear rotor problem in that it would 'grab' every rotation of the wheel. I felt it while braking at slow speeds. No issues while braking at high speeds. I finally checked that rotor with a dial indicator and the run-out was off just a little. I replaced the rotor with a used off ebay and while that rotor also had a little bit of run-out it was within spec and less than the 'bad' rotor. The replacement rotor solved my problem. So, in other words, it doesn't take much of a warp to cause an issue.

Oh, and you have a Gen II FJR. Your real wheel will not lock. And I have found it extremely difficult to actually get to the abs activation on the rear of a Gen II FJR. Are you really sure you have a problem?

 

[BwanaDik]

While in the process of changing tires yesterday, I did the front first, installed Ride-On sealant and took the bike for a 20 mile ride to see if I needed to add weights.

Did you even change the rear tire before you went on the 20 mile ride? Not real clear here if you did or not. If you did, Ionbeam's answer is correct.

Changed or no?

 

[Bill]

I noticed that the rear brake didn't feel right before I changed the rear tire.

After I changed the tire and put it back on the bike, I found that it would grab that section tight enough to stop the spin of the wheel and require a bit of hand pressure to turn it past that section.

I just went out to the garage and put the tire on the balancer. When holding a metal carpenter's square alongside the rotor, I can actually see the rotor come close to the straight edge, scrape against it, and then move away from it.

Perhaps the warping was beginning before yesterday and the drag on the brake wasn't enough for me to notice it. The rear pads don't look overly worn for 47,000 miles or should I say that the pads aren't much more than 50% worn out.

 

[Andyfjr]

47k. Well its seen plenty of use then. My mates rotors on his 99 ST Sprint were shagged at 40k, well below the thickness recommended.

 

[HotRodZilla]

If your rotor on the FJR is done at 47k, something is wrong. When's the last time you cleaned your brake pedal pivot? Maybe your pedal has been dragging and the heat caused early wear.

Are you sure you reassembled the calipers and rotor correctly? I've heard it's possible to get the pads all to the rear of the rotor, causing a drag and a Hellavua racket.

 

[Afast03nNJ]

did it just overheat from a stuck brake pedal?

Same thing happened to me and caused the following to happen as well.

I couldn't press on the pedal hard enough to lock the brake

The stuck brake pedal caused the pads to drag and overheat causing brake fade.

Lube the pivot point on the pedal, hopefully your rotor is still OK.

You can scuff the pads slightly if there glazed over.