| Author | Message | ||
     Philip |
help! i have a 99 m-2 and recently replaced the front pads. now it seems the front brake starts dragging after doing some hard braking. i just made a run through the streets doing a lot of braking and i could hardly push the thing into the garage! i did squeeze the pistons out of the caliper a bit and cleaned the grunge off. what do you guys think? | ||
| Tripper |
Grunge got into one of the pistons and it is sticking, or there is air in the lines. If there is air it will expand when it gets hot. Try bleeding first. Otherwise a rebuild is in order. | ||
| Reepicheep |
A good dousing of the pistons with brake cleaner would probably help as well, you should get them good and clean while you have them off the rotor. | ||
| Hans |
Experienced it with an almost brand new Honda Hawk. Ended up with extruding the pistons completely (pumping the brake while fixing the easy ones with clamps in their inward position) Heavy white voluminous oxidation on the aluminum cylinders and only slight brownish discoloration on the bronze (?) pistons. (Hand) polished it all: Also the hanger pin. I camphered the hole in the pads very lightly to be sure, because I had ever an completely worn out hanger pin. Very small quantity of graphite grease on pin and gliding surfaces. All seals and rings renewed. The pistons have to go so smooth that you can push them with the flat of a screwdriver inward. Next 7 years no problems. No leakage. Not even when the handle was hard pressed, almost against the bar. That is no wonder because the sealing is done by the ring and not because extremely small tolerances between piston and cylinder. I still have the feeling that engineers will look upon my cheap fix (only seals and brake fluid) with horror. So I don`t advise to do it that way: Let it be rebuild by an authorized mechanic.  The first thing you have to look at, following the book, is the back stream valve, which will be not the cause because only some pistons are sticky. | ||
| Philip |
thanks for the input. i'll pull the caliper back off and get the pistons out and do a close inspection and cleaning. also was reading the shop manual and it seemed like my fluid level might be a touch too high. i never added any and when i replaced the pads i just assumed it was ok to just push the pistons in and the fluid would be ok. thanks again. | ||
| Blake |
You should probably change your fluid then too. | ||
| Philip |
well, after going on a short vacation with the family, i bleed three pumps of the mastercylinder through the caliper and lowered the fluid level. a short test ride around the hood doing a lot of braking and instead of the lever feeling like it was pumping up i felt a need to use more squeeze to stop. i do believe the fluid was expanding and causing the dragging. now i will flush out the old and put in the new fluid. thanks for the input. | ||
| Lake_bueller |
Can anyone expound further on a similar problem.... I replaced the brake pads and bleed the lines. I then found I had a warped rotor (let the brakes go a little too long). After removing the front wheel and replacing the rotor, I reattached the calipers and put in the new pads. Everything good so far. Loaded up the brakes with new fluid and bleed the line again. Now the pads won't release. I tried completely draining the brake fluid and re-bleeding the brakes. Now I can't get any pressure in the line. Thanks for any help!!! | ||
| Philip |
make sure your fluid level is below the ridge inside the master cylinder. that was my problem. also did you push the pistons in the caliper out with the master cylinder and clean them real good. i used q-tips and then pushed them back in and loaded up the pucks. remove the caliper to make it easier to get to them. also the manual says to gently pump the master cylinder with the top off and watch for a slight rippling of the fluid to show that the fluid is releasing. just don't pump too hard! | ||
| Philip |
just reread your post! no pressure eh? did you pump the lever to bleed in the new fluid or use a mytivac? i have let the fluid gravity feed before to fill the hoses and also tapping on the master cylinder can jog out some air. tap everything and see if it burps out some air. | ||
| Lake_bueller |
Well I went back through everything yesterday. I completely tore down the calipers and gave them a through cleaning. Reloaded the master cylinder with fluid, opened the bleeder, grabbed a cold beer and waited. It took about 25 minutes to completely fill the system with fluid (something they don't tell you in the manual  ). Burped myself, burped the lines and was set to go. I took her for a quick ride this morning and I'm happy to report that all is well  | ||
| Henrik |
Lake; the reason you had no pressure was air in the master cylinder. Pushing brake fluid from the caliper - up will limit air in the system. Also, a banjo bolt with a bleeder at the master will help you bleed the top of the system. If you don't have one, you can either take the master off the bar and vary the position to bleed air out through the reservoir. Another option is to loosen the banjo bolt a hair while keeping light pressure on the lever and squeeze the last bubble out of the master cylinder. Henrik | ||
| Thunderbox |
Hey Guys, Most manufacturers do not recommend topping up your fluid level in the master cylinder. It is normal to have the level drop when the pads wear and the pistons move out. When the level is to minimum it is probably time to replace the pads. If you added fluid during the brake wearing it will now be overfull and can cause your brakes to come on when they get warm and the fluid expands. | ||
| Cyclonemick |
Can you change your front brake pads on a 00m2 without taking off your caliper? | ||
| Marks3tbillet |
Hey Mick: Yeah you can slide the pads out without removing the caliper. It's real easy after you remove the pin and the spring clip. Don't you have a service manual for the M2? Mark Schroeder | ||
| Cyclonemick |
After studying the caliper this evening I sucsesfully changed pads with no problems. I couldn't wait for a reply because my pads were really thin and I wanted to ride in to work tonight and was woried that they would not make it into columbus without destroying my rotor. I still haven't bought a manual but it's next on the list of things to buy. I haven't bought one yet because my wonderfuly bike had been so good to me. But I guess I better get one befor they quit making them. Thanks Mark! |
