Brakes, brakes, and more brakes...

[paddy]

I began to notice the Djebel doesn't really stop very well. I think it's been getting worse but it's hard to tell - it's my first bike and I didn't really have a frame of reference until recently. To give you an idea, at 50 km/h I could pull the front brake lever as hard as I could with two fingers and it was a fairly sedate stop. I've been told that's not good.

I have a bunch of questions (I'll number them just in case people want to pick and choose what they answer):

(1) I decided to replace the disk and pads. The disks are darned expensive here, but does anyone see any problem with this:

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=150368023796

(2) I have removed the front brake house and intend to replace it with a braided line. I've been quoted around $70 by Coleman's Suzuki which seems pretty good to me. Are there any pitfalls to this? Should it be the same length/shape? I had figured on just handing them the old hose as a template.

(3) With the pads removed when I pump the brake handle only one of the two pots really moves. If I clamp that pot still, the other still really doesn't move all that much. Is this expected, or is it poked? In which case is it likely to just be seals or should I plan on replacing the whole calliper? (There is no visible fluid leaking.)

(4) The handlebar fluid reservoir (that's not even close enough for the spiel check to guess) is full of fluid, but if I pump the brake handle nothing much comes out. If I leave it to sit for a while then the first pump issues some fluid, but each subsequent pump does not. Is this expected? Does this mean the master cylinder seals are poked? I do note that the rubber boot that protects the plunger is all but missing. I found a whole new unit on ebay. Should I just buy it?

http://cgi.ebay.com/ebaymotors/NEW-F-BRAKE-MASTER-CYLINDER-DR200-DR250-DR350-DR370-DR_W0QQcmdZViewItemQQ_trksidZp3286Q2ec0Q2em14QQhas hZitem1c0c1f8ca7QQitemZ120462478503QQptZMotorcycle sQ5fPartsQ5fAccessories

It doesn't have a buy now but they seem to be closing at ~USD50.

(5) When I replace the wheel, I understand that I should grease the axle. Is Castrol LMX (lithium based grease coloured blue) appropriate? Should the portion of the axle that is clamped by the pinch bolts be free of grease?

That oughta do for now. I might get this finished before I go taking on the chain and sprockets.

[F5 Dave]

ok well first things first. is the std disc worn or warped? if it is straight & has some ok thickness any grooves can usually be taken out, even just running it on a lathe with some hand held (carefully) sandpaper on a block should be enough.

That disc is obviously aftermarket. It may be ok, really couldn't say, I'd probably risk it for the money.

Yes braided line on old one template.

ok the calliper is the most likely issue. It will need to be stripped & cleaned, seals carefully taken out & inspected (surprisingly usually ok, but replace any that are twisted/worn). Hopefully pistons polish up ok with some light polish, try not to remove plating.

The grime that lives behind the seals & on the pistons will partially seize them making braking grim. the sliding pins need to be free & greased with copper brake grease (keep away from pads).

Taking the pistons out can be a real bitch, best to have a bleed system & push the pistons almost out one by one & hold one in position with a small sash clamp (supercheap $4 or whatever) & pump the other one which will unsieze with hydraulic force now it's the only one that can move.

If it really isn't playing ball you can pop them out with compressor, but you have to be more than a little careful & wrap a rag to restrict pistons & stop them emerging at 400mph
they then need to be scrupulously cleaned & then the seals can be put back in (avoid anything touching them apart from brake oil).

ok here comes the frustrating part, bleeding the brakes. As you've found out the master cylinder needs to be bleed or it will appear to pump nothing. unless it is leaking it is likely ok. Read up on internerd on bleeding.

Don't use an old brake fluid bottle.

Then pads. This is tricky, many are rubbish, you kind of have to try some. Std suzi ones will work as well as the best but are often more expensive. the big thing is your old pads could easily be contaminated by a past leaking fork seal or wash detergent or whatever, they never recover from this sort of thing.

will take a little while but it is worth it.