A sticking rear brake – 1 Nov 2018.

A few days back I described how the back brake on The V7 700 Fire Bike was sticking on. If I used the brake the pedal would stay down, the brake light stayed on and the brake would drag. Today I had the chance to take a look at this. I also took a look at the gearbox leak on the V7Sport but will have to report on that later as I’m waiting for a replacement part.

I was fairly sure that the problem was within the rear brake drum so removed the left hand pannier to get at it. I disconnected the brake linkage from the drum.

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I was surprised to find that I was wrong and it was actually the brake pedal pivot on the frame that was causing the stiction.

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I removed the pinch bolt then tried to remove the lever. I had to spread it a bit but found that it still wouldn’t come off because the footpeg was in the way. It’s pretty tight between the starter motor and footpeg.

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I considered removing the foot rest but this appears to be quite a job. The bracket is held by the bolt which mounts the gearbox to the frame and by a couple of smaller ones to the leg shield. That big bolt will be hard to loosen as the exhaust pipes make access difficult. I am concerned that it is frozen in place. Idealy the engine and gearbox mounting bolts should be turned from time to time to ensure they stay free or, perhaps better, should be replaced with stainless steel copies. Anyway, I decided I would give this prospect a miss. I checked my manuals and parts books and saw that there is no reason why it shouldn’t be possible to knock the pivot back a little through its bracket. You can’t bash it right out because there are plenty of other parts in the way.

I spent a long time squirting dismantling fluid at it and wiggling the pedal up and down. Eventually I thought it was free enough to attempt driving it back through the pedal with a drift. I managed to get it to go back a few millimetres but that was all the clearance I needed to get the brake pedal off the shaft.

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I refitted the lever at a diferent angle and continued to try and work the shaft free but eventually resorted to carefully heating the end of the shaft with the fine burner on my blowlamp.

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I surprised myself and managed to do this without lifting the paint from the frame. Once it was good and hot I doused it with penetrating fluid and produced large amounts of smoke. A wiggle confirmed that it was a bit better and the process repeated with more improvement.

The spindle was brought back through the frame mounting and the job done again. I was happy that it was now freed off but it had to be knocked back once more so that I could get the pedal back on

Once all together I was able to confirm that the problem is fixed, at least for now, and I can ride the thing. At some point this will all have to come apart for that shaft to be properly greased. I don’t want to just rely on WD40 as a lubricant. However, it will have to do for now. I can also foresee hours of entertainment moving that gearbox mounting bolt and possibly the front engine bolt as well. I should have known better and removed and lubricated them before. Ho hum.

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