my rear brake had been squealing. I looked at the pads, and they appeared to be starting to get low, so I figured wtf, I'll slap a set of pads in. I loosened up the pin, pushed the piston back with the old pads, and put the new ones in. Now I have a mushy pedal. I didn't open the hydraulic system up at all, just pushed the piston back. I bled the brakes until I ran out of fluid, still, no pedal, just soft, barely pushing the pads. I pinches off the hose to the rear caliper, and the pedal is hard as a rock, so I know it's not the master cylinder. Anybody had this happen to them?

 

You may have a tight piston. On a 4 piston system, a tight piston will cause a squeal. Never push them in when you change them. Pull the caliper off and insert a shim slight smaller than the rotor. Press the pedal or lever to expand the pistons slightly further out. Now remove the pads and shoe shine the pistons spotless. Now push them back with the master open and sucked down about 3/4. Refill the master and push just a small amount making sure both or all 4 pistons move move out the same. If so, then replace with new pads. You should rebuild caliper ever other shoe change or if they do not move the same. Be sure to use the proper piston grease if you rebuild.

 

Appreciate the input, but it's only a single piston, about 1 1/4" diameter. the bike has 10,000 fairly easy miles on it. I just can't imagine what could have happened by simply pushing the caliper piston back in, as it shows in the factory manual. the master cylinder is not the problem, it's making plenty of pressure. and i know the piston isn't stuck because it pushes in easily. If it's air in the system, I'd like someone to explain to me how it got there. I used to work at Toyota dealerships, and done hundreds of brake jobs, never seen anything like this

 

I know you can suck air past a master cylinder cup when you use a vacuum pump to manual bleed from the caliper end. Are you sure the problem is air since you say you bled after the job when you had the soft pedal? I manual bleed trying not to bottom the master and not let up on the lever or pedal until snugging the caliper. I also always have the bleed hose in a few inches of fluid watching for bubbles. Guess you ought to be puzzled. You have done more brake jobs than me.. It is interesting because you read about people having trouble getting the air out of the lines on a Harley all the time on here. Have even read here people saying the dealer used a rubber band on the lever and left it overnight. Crazy sounding to me. I rebuild the calipers on a 2005 CRV about 6 months ago. Now when you hit the brake you hear a click. I finally rolled up using the hand break and pulled the front wheels.. For some reason, the calipers after braking are pulling the piston back in just a tad too much and that is the click. Have yet to figure why.

 

make sure all the hardware, shims, and spring/anti rattle parts are there and in good shape

as far as my dilemma goes...I would not have touched the hydraulic part of the brakes had the pedal not felt the way it did. stuff like this mystifies me. you just take the pin out, push back the piston using the floating part of the caliper body, slide the pads in stick the pin back in, tighten it up, pump the brake a couple times, and you're done...I must have taken it apart and put it back together 6 times, looking for something i could have done wrong. about ready to throw in the towel and just take it to HD and tell 'em to fix it