I'm curious about how the calipers work on my M696. So I've been told that its normal for brake pads to constantly rub on the rotors a little. That means as the pads wear, the piston (at its rest state) is ever so slowly pushing the pads closer to the rotor. I ask because I'm about to put on some new brake pads. The new pads are obviously thicker than the old pads. So do I have to push the piston back to get the new pads to fit?
2nd question. What is the benefit of this system vs. let say the system on my mountain bike? My mountain bike has a knob that I can adjust how close the pads are to the rotors when the brakes are not pressed. When the pads wears (increasing the gap between the pads and rotor) I can manually bring the pads in closer. Yes, this require me to adjust my brakes every now and then but I'm not constantly dragging on the rotors.
Quote from: mysticbluex3 on March 28, 2012, 04:31:26 PM
I'm curious about how the calipers work on my M696. So I've been told that its normal for brake pads to constantly rub on the rotors a little.rubbing is a bit overstated - "just barely touching" would be more like it That means as the pads wear, the piston (at its rest state) is ever so slowly pushing the pads closer to the rotor. it's really just adjusting it's static position to accomadate for wear. the calipers are never squeezing the rotor unless the brake lever is being squeezed. I ask because I'm about to put on some new brake pads. The new pads are obviously thicker than the old pads. So do I have to push the piston back to get the new pads to fit? yes. that's normal. just make sure you push the pistons back evenly. you will be pushing fluid back into your master cylinder's reservoir so be sure it doesn't overflow. use spray brake cleaner on the pistons to get any gunk off them first.
2nd question. What is the benefit of this system vs. let say the system on my mountain bike? your bicycle's brakes aren't designed to haul a 600lb bike/rider down from triple digit speeds. My mountain bike has a knob that I can adjust how close the pads are to the rotors when the brakes are not pressed. When the pads wears (increasing the gap between the pads and rotor) I can manually bring the pads in closer. Yes, this require me to adjust my brakes every now and then but I'm not constantly dragging on the rotors. that's the beauty of hydraulic disc brakes. they never require adjustment since they always "park" in the perfect position. your Monster will never feel whatever tiny amount of drag there might be from your pads (just barely) touching the rotors
+ with this system when you apply the brakes they are there straight away, with your mountain bike system the caliper has to push the pads onto the disc initially before any breaking can take place - would you want a slight delay, or at worst to have to pump the lever first?
Quote from: sofadriver on March 28, 2012, 09:03:20 PM
The new pads are obviously thicker than the old pads. So do I have to push the piston back to get the new pads to fit? yes. that's normal. just make sure you push the pistons back evenly. you will be pushing fluid back into your master cylinder's reservoir so be sure it doesn't overflow. use spray brake cleaner on the pistons to get any gunk off them first.
make sure you have the resovoir open and drain off the appropropriate amount of fluid to be within resovoir fill specification...otherwise you could potentially end up with the fluid expanding and nowhere for it to expand to and your brakes will lock up which sucks to have happen
Quote from: mysticbluex3 on March 28, 2012, 04:31:26 PM
2nd question. What is the benefit of this system vs. let say the system on my mountain bike? My mountain bike has a knob that I can adjust how close the pads are to the rotors when the brakes are not pressed. When the pads wears (increasing the gap between the pads and rotor) I can manually bring the pads in closer. Yes, this require me to adjust my brakes every now and then but I'm not constantly dragging on the rotors.
Your bicycles brakes are cable actuated right? That's the reason for your adjustment knob. On the moto, the reservoir functions to 'auto adjust' for the wear. As the pads wear down the fluid level in the reservoir drops as more of the fluid is in the cavities behind the pistons in the calipers. The volume of fluid is the system is fixed - a constant - given variances for thermal expansion. It's just allocated as needed auto magically.
You shouldn't have to worry about the reservoir overflowing unless you have added fluid recently with worn pads or the new pads are hard to slip in. The master adjusts itself as the pads wear to keep the lever feel the same. The MTB brakes are probably set up like that to keep your rolling resistance down, since even going from a tire with 1/8" knobs to 1/4" knobs makes a huge difference in how efficiently the bike rolls. It doesn't make any difference with 75 hp though!