Unusual Rear Brake Problem

Hi Folks !

Came across an unusual situation today that I've never encountered before (over several years of biking). It involves a problem with the rear brake.

I was out on my VX800 this afternoon & had been riding in the Yorkshire Dales. I had ridden over one section of road (about a mile long) that had been recently covered in chippings. There was the usual 'loose chippings' warnings & advisory speed limit .... & normally you consider possible skid risks or traction issues, or being hit by stones flung up by other vehicles. Well I'd ridden this stretch with no significant issues, but a couple of miles down the road my VX seemed to be running a bit 'off', similar to an air-cooled engine getting 'hot'. This eased a little, but I stopped at the first decent layby to look things over.

I was riding with two buddies & one asked me to check my brake light as it seemed to be stuck on for the last few miles.

On close inspection I could see that a very small chipping had lodged between the rear master cylinder pushrod clevis and the pivot boss of the rear brake pedal (See photo - it was trapped in the area where the Bic pen nib is positioned)



This prevented the rear brake being fully released & was also causing the rear brake light to remain on. Whilst there was only light brake pressure at the time I inspected it, I do wonder if a bigger chipping had lodged at a different angle and caused a bit more pressure at the time when the motor felt to 'bog' down.

There was some heat in the rear disc (as you would expect in such circumstances). I will strip the pads out & check for premature wear. I am also going to change the brake fluid (Even though I did replace it in July last year) as excess heat can reduce the efficiency of brake fluid (A problem I encountered in speed-climbing several years ago). As brake fluid is inexpensive, it is best to replace it (Safety critical component).

As mentioned - this is something I've never encountered before, & the chances of it happening to me again are probably very slim - but I thought it worth sharing for the common good.

The VX800 has a 'conventional' riding position (not feet forward controls), so this issue might not happen on a cruiser with feet forward controls - but it would be worth looking at your linkages to see if there may be a similar 'trapping point'.

It's certainly something that is easy to do a visual check on - & I probably will watch this area for awhile, until my fading memory causes me to forget to check.

Many other bikes will have a similar set up - so worth a once over !

Cheers folks    Yam

There is always something that makes you think & that's one Glad you found & sorted it so easily. hope you still have a descent shoe left when checked. Thanks for sharing, goes to prove how even when we maintain or bike properly, there will always be something to catch us out.

Good shout Yam, glad you found the problem so easily, strange one but so easily done I spose   

Hi folks !

Just as an update .... today I changed the brake fluid - it did not look too bad, but as it is an easy job it got done anyway.

I then took the rear disc pads out (opposed piston calliper). There was a good bit of brake dust in there which I carefully cleaned out. The wheel rim also had recent brake dust deposits, which simply wiped off. I probably lost a few hundred miles of pad use - but there was plenty of 'meat' left on the pads.
I cleaned of the pad locating pins & re-greased them (& the edges of the pad backing plates).

All was soon back to normal, & functioning as it should.

The friction face of the disc looks normal, but when looking on the thickness of the disc (from the rear) & spinning the wheel there seemed to be a slight blueing of the edge of the disc in some places. I spun the wheel up & the disc appeared to be running true - so no warping etc.
Looks like I'd stopped in time & have thus avoided an significant problems.

I tried to simulate the amount of brake pedal deflection that the small chipping had caused and this was only producing light brake pressure, but enough to leave the brake light on. I could turn the rear wheel by hand, but there was noticeable resistance to turning. It is easy to see how heat would have built up over the few miles I must have run. The rear disc was warm, but not excessively hot when I managed to park up in a safe place.  


As said before - this is a 'rare event' and it was the first time I've had such a problem in several years of riding. I would be surprised if it happened to me again - but being so unusual I thought it worth sharing for the benefit of others.

Thanks Dave for putting this post in the appropriate spot     

Cheers folks     Yam

 Good shout Yam, go's to show you, we never know what surprise's are waiting for us,     

Good shout Yam  

Nice one Yam, good to read  

Nice one Yam, always good to read what you write on numerous levels. Glad all's sorted.