Post 2 - Fixing, finally, that bloody back brake

This is the second in a series of blog posts detailing my preparation for a trip to France on my VFR.

Back brakes and Nevin have rarely gotten on well thinking about it now. On the Honda Innova that I first rode the drum rear brake would consistently squeak and, in wet weather, it would want to lock up. Being a drum brake it never gave much in the way of feedback anyway, you could never tell what it was doing. It's use then was extremely limited. This continued on to my next bike, a Suzuki Bandit 600. The rear Tokico opposed piston caliper is a mainstay of many Japanese bikes, the same set up being used in any other bikes of that era. Mine worked for a while but then I could start to see a dust seal worming its way out and I could never manage to open the caliper to actually rebuild it. Buying a used caliper did help but I never think back to the Bandit with thoughts of a great rear brake. The VFR, for the last months, has gone down a similar path. When used the rear would simply want to lock itself in place. You can imagine it is fairly disconcerting when filtering through traffic. I had put new seals in the caliper last summer and had even cleaned out the master cylinder thoroughly only a week or so ago. And still the rear brake was binding. That means, when used, the brake would not retract and would still be, well, braking. The engine thus has to work harder, the rear brake heats up a lot more than normal etc etc.

Well today I went into the workshop and decided it was time to take the caliper off, take the seals out and scrape the bores clean. If you don't know how a brake caliper works, here's a quick run down - when you press the pedal, or pull the lever, you are pushing brake fluid along a hose/line into a caliper. In here we have a piston, or two, or three, or four, or six. The fluid pushes against the piston which moves outward pushing a brake pad against the brake disc and thus slowing your machine down. Rubber seals stop the fluid from escaping past the piston but allow the piston to move freely. In theory. On mine corrosion and dirt had built up behind the seals, causing the piston to "jam" up and keep the brake on. This was especially so if the brake was hot as the piston would expand ever so slightly. We are talking tenths of millimetres here but it all counts. Here's a picture of the dust seal bore with the dirt all gunked up inside:

It looks like a black ring but that is dirt and corrosion.

I didn't have new seals to hand for this job so I had to be extremely careful in taking the seals out and then cleaning the bores. I used a bunch of small seal pullers which look like needles and just scraped everything away until I was left with bare alloy again. Such work reminds you of the age of the machine. I had been pretty angry about this rear brake for some time but when you actually go and look at this closely, and the work and the machining that was involved when the part was made, you can see a real complexity going on. Obviously it is nothing compared to a brand new Brembo monobloc but there is a lot going on nonetheless. In appreciating that complexity you can find yourself forgiving the machine for many faults. Just so I can get to work or college or go have a bit of fun on a nice road an awful lot of parts have to work perfectly and in tandem. While working on a delicate part of the bike and using tools that look like they came from a kids Fisher Price set you sometimes can better step back to see the widescreen technicolour picture, the full view. By the time I was finished with these thoughts the bores had come to look like this:

Spick and span on the left and on the right one piston in and the other out with red rubber grease smeared lightly on the bores to help prevent future corrosion.

Now that they were all clean the red rubber grease could be smeared on, seals reinserted after a clean and an inspection and then the pistons could be slid back in .One was almost impossible to remove at first so, from the get-go, I knew I was on to a winner in looking at this stuff. As I had the Dremel out, well it's a fake one, a Bremel (not really, but it is crap), I decided to do this. It's a little naff but I think it fits the VFR style and gives Nissin some credit for producing decent brakes after my devolution on complexity earlier on. 

Bleeding the whole system was, as usual, a pain in the arse but once it was done I was able to ride home and use the back brake properly with no fear of it locking or binding. It acted just as a back brake should, stabilising, progressive in nature etc etc. It will surely be useful in France. As an aside I also gave my front calipers a quick bleed. New fluid had been put into that system last week but another bleed tonight after a week of use made them firmer again. I prefer to have more "feel" at the lever so I backed off the adjuster which makes you feel like you have to pull the lever for a longer distance but with the benefit of you gaining more of a feel for what the front brake is doing. Perfect.

Coming home brought my feet firmly back to the ground and reminded me of the niche nature of this blog and of working on the bike in general. I had commented with a good friend of mine who pilots an SV650 that fiddling about with bikes in our club workshop is very much a niche thing. He was amazed at how we all became excited at me bringing in a tub of red rubber grease and how we talked about o-rings. It's not bus stop or elevator talk. Or water fountain talk. Neither is it hallway talk. I was informed upon coming in to the house that some areas were just painted so I should be careful. Then I was given a rundown of the day and while I packaged my day ("Well I did this, that, and the other thing, and fixed my back brake") I listened and waited. I never got to unpack that packaged summary of my day which was frustrating because I felt like I had conquered a little bit of the world in fixing this problem. I wonder does Putin feel like that over Crimea, it being a small part of the world? His issues end up on global news however, mine haven't. Yes, it's niche alright but I am sure those reading this appreciate this as much as I do.

I did not take any photos of this but I also cleaned some areas of the swingarm as I was in that general vicinity. That swingarm has a history all of its own which you can read a little of here. The Elf endurance racers, and Honda's relationship with them, basically ended up with Honda gaining some patent rights to a very nice piece of kit. It's heavier than a conventional swingarm but it looks cooler, allows for quicker tyre changes (important for endurance racing back in the day), makes chain adjusting easier and, again, looks cool.

Anyway, there's another job off of the list of things to do before France. I still haven't worked on a list of things I need to bring with me but I did do a few minutes thinking over what documents I will need to photocopy. Still, I reckon fixing this rear brake was that bit more important. Next up is to decide whether or not I'll be needing a rear tyre... In the meantime however I think it is time to begin listening to the next Motopod (if you haven't listened to Motopod and are interested in bike racing, get yourself over to motopodcast.com. Until next time!

Thanks to the kind members of the VFR club on bikersoracle.com, the VFR 750 RC36 group on Facebook and World Motorcycle Community on Google+ who suggested the bore corrosion issue to me. All are fantastic support networks with great members who like to suggest that a certain colour can make a certain bike go faster!