What's in your brake system?

I thought I'd have a look at the caliper on my Mk3, as I'm fitting a reconditioned master cylinder and braided lines. To say it's a bit of a horror story in there barely covers it! First clue was the brown sludge in the reservoir, then upon stripping the caliper the goo pictured below was revealed...







Now I've had this bike for a year or so & rode it a bit to assess what needed doing; the brakes worked... On stripping the master cylinder it was worse, if anything. This bike had a long term owner for 20-odd years before that, and visited a well-known dealer pretty much annually during that time. It seemed they never thought to check, or change the fluid. Maybe the problem with hydraulic brakes is that they are pretty much 'maintainance free', leading us to leave well alone? It has made me think about my other old-ish crocks, maybe a dose of looking at wouldn't go amiss there too.

Yep signs of never being flushed out with new fluid, I do mine every 3years without failure, I now run a full Grimica brake system on the front of my Norton, a lot better than the old 40 year old system, but if you have been happy with your brakes then just pull it all apart put give all the parts a good clean and new kit in the M/C and caliper and flush the systen with new fluid and you should be good to go again, there are a lot of upgrades you can do to the old brake system to make it work better, I was lucky and had the money to replace the front brakes to a moden system, there are better brake around but it all depends on how much money you have, I am very happy with my Grimica brake system.
Another thing to look at is the rubber brake line on the front, they get old and the rubber swells up inside to block the hose, best to replace with a S/S brake line, it happened to my orginal brake line.

Ashley

It is a good idea to flush the brake fluid every year or so, the more humidity in your region the more important this is, it absorbs moisture which reduces the boiling point of the fluid.

Even Dot 5 silicone will turn to munge eventually.

The old brake fluid absorbed water the modern silicone one was better, but you should still change your brake fluid every 18 months, I Never leave mine in longer than 2 years, when I change ALL the seals, brake failure is one thing I can live without.

Likely this does not apply to anything yoose guys should be concerned with but interesting read on DOT 3, 4, 5 and 5.1. Not mentioned in the short article but based on real life testing is DOT 5 & 5.1 do not react with each other if put in same system, ie: nothing precipitates out or gels to clog passages but they are different densities so separate out like oil and water which is interesting but don't effect brake function other than innate silcon fluid properties covered in URL's.
http://www.tbmbrakes.com/silicone_brake ... rake_fluid
http://www.gomog.com/allmorgan/brakefluids.html
and of course if its British based brakes might consider Moss Motor conflicting statements to judge for more reason to aviod British made brakes.
http://www.mossmotors.com/SiteGraphics/ ... page1.html