After putting some thoughts together regarding road brake maintenance I thought I should even the ledger and chime in with something for mountain bike brakes :)
If your MTB has v-brakes you can pretty much follow the advice for road brakes posted earlier, if it has disc brakes then read on my friends and hopefully I can enlighten you some what?
When servicing disc brakes there are a few simple things that when done regularly keep the brakes performing better.
Something I advise anyone looking to buy or who already has an MTB is NEVER EVER use spray oils, spay polishes or spray cleaners on your disc equipped MTB (IE when lubricating the chain etc or when cleaning your bike). The reason for this is most newbies (and some experienced riders) are never told of brake contamination. This occurs when oil or cleaning products get on to the disc brake rotor and when the brake is applied this is transferred to the brake pads :( This leads to brake contamination and if severe can lead to replacing brake rotors and brake pads (shops love this as it is big $$$$) I had one customer who after racing a 24hr adventure race, cleaned her bike nicely. The bike started to show signs of corrosion on the steel brake rotors so thinking she was doing the right thing she sprayed oil all over the disc brake rotors :0 :0 :0 OMG NOT GOOD. This led to new rotors and brake pads front and rear $$$$.
How do I know when my brake is contaminated I hear you asking? Well the tell tale signs are if the brake SQUEALS like a little piggy :) when applied and/or if when you wipe the brake rotor with a clean rag/cloth there are traces of oil. The traces of oil will normally leave black smudging on the rag/cloth. (and ALWAYS use clean rags/cloths on disc brakes to avoid contamination from dirty rags/cloths)
Cleaning pads and rotors. I find the easiest way to clean brake pads and disc brake rotors is using either a commercially available auto disc brake cleaning product (keep it away from your bikes paint though as it can do nasty things) or using isopropyl alcohol or rubbing alcohol.
The easiest way to clean your rotors and pads is by removing the wheels from the bike. Just remember not to pull on the brake levers if you have hydraulic disc brakes as the pistons can stay out. If you or someone else does apply the brake lever when a wheel is out just find a tool or something of a similar thickness to the rotor and wedge it in to re-open the pads. I like to use a hub cone spanner as they are almost the same thickness as the brake rotor, you can also use a large flat bladed screwdriver and push it up between the brake pads. NB do not twist the screwdriver to open the pads as you can/will damage the brake pads. Just push it up between the pads to open the pad spacing.
This tool from Park Tools works a treat
Slide the polished, wedge shaped tool between pads to expand the gap and pre-set the pistons into the caliper
Useful if you have accidently pulled the brake lever without your wheel and brake disc in the bike
Reset the pistons without disassembling the caliper or removing the brake pads
Do not be concerned if you open a little wider than the rotor thickness as the pistons will reset the correct spacing when you re-apply the brake with the wheel installed.Then apply the brake cleaner/rubbing alcohol to a CLEAN cloth/rag and rub the disc rotor, see that black stuff coming off, that is what you want to get rid of :) Keep applying and clean both sides of your rotors until there are no signs of contaminants coming from the rotors.
For the brake pads you can fold a CLEAN cloth/rag over a few times to make a thickness similar to the thickness of the rotors, apply cleaner/rubbing alcohol to the rag/cloth and then run it up and in between your brake pads.
When servicing brake rotors and pads I like to remove the rotors and pads from the bike and clean thoroughly as above, then I give the rotors and pads a light sand with sand paper to roughen the surfaces up a little and get rid of the shiny brake pad surface. This generally eliminates brake pad squeal :) If you are unsure as to what is involved with removing the rotors or pads then I suggest getting a brake service done by the local IBD.
If when refitting your wheels the brake drags on one side you will need to re-center the brake caliper to the rotor. This can be time consuming depending on the brand of brakes you have. The best thing to try first is to loosen the top caliper mounting bolts (the two bolts you can see when looking down at the brake caliper) that hold the caliper to the brake mount. Then apply the brake and lightly tighten the same bolts. Spin the wheel and see if there is no rubbing? If there is still rubbing or brake drag, loosen the bolts a little and move the caliper a fraction with your hand, retighten and check again. This can be a little time consuming on some brakes.
If a rotor has a bend in it there are tools to straighten the rotor. I would suggest you let the mechanic at the local IBD have a look at this for you as you can easily warp a disc beyond repair if not careful.
As for lever maintenance and hose maintenance there are a couple of things you can do. Lubricate the brake lever where the lever pivots in the lever body and if need be you can adjust the feel of the brake lever by either turning the adjuster(if you have certain Avid or Shimano brakes) or by dialing in the allen key adjustment that adjusts the lever position.
These adjustments will either pull the lever closer to you or push the lever further away. You can periodically wipe around any hose fitting to see if there are any hydraulic fluid leaks. If there are signs of hydraulic fluid then it is off to the local IBD for you :) For a cable disc brake equipped bike follow the same instructions for lubricating the cable as in the road blog I posted and to align a mechanical brake caliper I find the following advice works best.
Loosen the cable tension and the top caliper mounting bolts; align the brake caliper as close to the cable housing side of the rotor as possible with no brake rotor drag and tighten the caliper. Next I wind the other pad adjuster in enough so that the pad nearest the spokes isn’t quite dragging or touching on the rotor. Then I set the cable tension and tighten the cable adjustment bolt. This should give the best feel for cable dis brakes :) An extremely good method of adjusting Avid brakes can be seen here;
this will work for most if not all cable disc brake setup’s :)
Another thing that is rarely considered is the brake lever position relative to the rider. Correct position for your brake levers should be so that when you apply the brake your hand sits naturally on the handlebar and brake lever. Too many bikes are left set up in the factory position with the brake and shift levers set hard against the handlebar grips, this makes braking awkward as the wrist has to be turned out to allow the index and third fingers to pull on the brake levers. Another consideration is the brake lever angle which theoretically should be in line with your arm in a straight plane allowing your fingers to go straight to the lever when braking. If the lever is too high you need to cock your wrist back to get to the brake lever and if set too low you need to over reach to use the brake lever.
This article from www.bikeradar.com explains all this and more
of particular interest to us is the brake adjustment section.
I hope this article helps and stay posted as I hope to add a few more tips regarding bike maintenance/servicing as time passes.
Shane at SR Bike Works.