Hydraulic Rear Brake sticky
10-25-20, 01:57 PM
#1
Senior Member
Thread Starter
Hydraulic Rear Brake sticky
brake is for a 2016 Trek Farley 9.6
Alvio brakes
Rear brake is sticky. when i press the level is fine. However the pads dont retract all the way. I have taken air out of the line by from the handle bars and took a few drops out which worked. However pads still dont retract all the way.
suggestions?
Alvio brakes
Rear brake is sticky. when i press the level is fine. However the pads dont retract all the way. I have taken air out of the line by from the handle bars and took a few drops out which worked. However pads still dont retract all the way.
suggestions?
10-25-20, 02:52 PM
#2
Senior Member
Join Date: Feb 2012
Location: Rochester, NY
Posts: 18,056
Bikes: Stewart S&S coupled sport tourer, Stewart Sunday light, Stewart Commuting, Stewart Touring, Co Motion Tandem, Stewart 3-Spd, Stewart Track, Fuji Finest, Mongoose Tomac ATB, GT Bravado ATB, JCP Folder, Stewart 650B ATB
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4195 Post(s)
Liked 3,837 Times
in
2,295 Posts
When you bled the lines did you also pry back in the pads (I use a clean cone wrench between the pads)? Sometimes the pad piston can hang up within it's cylinder from grime and needs a few cycles in and out to clear the build up. Andy
__________________
AndrewRStewart
AndrewRStewart
Likes For Andrew R Stewart:
10-25-20, 06:04 PM
#3
Senior Member
Join Date: May 2010
Location: midwest
Posts: 2,528
Bikes: 2018 Roubaix Expert Di2, 2016 Diverge Expert X1
Mentioned: 14 Post(s)
Tagged: 0 Thread(s)
Quoted: 482 Post(s)
Liked 151 Times
in
105 Posts
Sometimes the pistons get grimey and gritty and stick. You can clean them off. google videos on how to fix a sticky piston.
10-26-20, 01:23 AM
#4
Senior Member
1. Remove the wheel and the brake pads.
2. Press the brake lever multiple times to make the pistons move out. BEWARE not to overdo it as you don't want a piston to fall out of the caliper.
3. Grab a piece of string and soak in isopropyl alcohol.
4. Pass the string around the pistons and pull both sides alternatively, making the string rub the piston. Do it from both sides until the piston is totally clean.
5. Carefully push the pistons inside the caliper, replace the pads and the wheel, and check if it works.
Before doing this though, make sure there's no air in the caliper. Any bubble stuck there can cause a sticky piston.
2. Press the brake lever multiple times to make the pistons move out. BEWARE not to overdo it as you don't want a piston to fall out of the caliper.
3. Grab a piece of string and soak in isopropyl alcohol.
4. Pass the string around the pistons and pull both sides alternatively, making the string rub the piston. Do it from both sides until the piston is totally clean.
5. Carefully push the pistons inside the caliper, replace the pads and the wheel, and check if it works.
Before doing this though, make sure there's no air in the caliper. Any bubble stuck there can cause a sticky piston.
10-24-21, 05:48 AM
#6
Senior Member
Join Date: Aug 2011
Location: Paris, France
Posts: 2,497
Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 573 Post(s)
Liked 118 Times
in
99 Posts
Hello,
My city bike has Shimano BR-M395 hydraulic disk brakes, and I've been riding it happily for years.
Starting a few days ago, I noticed the rear wheel would stop very fast after spinning. Since the tire wasn't rubbing against the fender, I assumed it had something to do with the brake.
After removing the wheel and pushing the pads outward with a disk piston press, I notice the left-side piston isn't fully retracted, while the right-side piston is almost fully retracted.
After loosening the two Allen nuts holding the caliper on the frame, and pressing the disk lever while tightening the nuts to adjust the caliper, the wheel is spinning better, but I can hear the pads rubbing against the disk.
Before I go ahead and clean the piston as shown below and in the Park Tool video above, do you confirm the left piston should lie further inside the caliper, ie a case of sticky piston?
Thank you.
--
Edit: I juste dabbed a bit of brake fluid around each piston with a Q-tip, pulled slightly on the lever, noticed the left piston moves in and out, used a clean rag to remove the excess fluid, and it seems to have done the job.
My city bike has Shimano BR-M395 hydraulic disk brakes, and I've been riding it happily for years.
Starting a few days ago, I noticed the rear wheel would stop very fast after spinning. Since the tire wasn't rubbing against the fender, I assumed it had something to do with the brake.
After removing the wheel and pushing the pads outward with a disk piston press, I notice the left-side piston isn't fully retracted, while the right-side piston is almost fully retracted.
After loosening the two Allen nuts holding the caliper on the frame, and pressing the disk lever while tightening the nuts to adjust the caliper, the wheel is spinning better, but I can hear the pads rubbing against the disk.
Before I go ahead and clean the piston as shown below and in the Park Tool video above, do you confirm the left piston should lie further inside the caliper, ie a case of sticky piston?
Thank you.
--
Edit: I juste dabbed a bit of brake fluid around each piston with a Q-tip, pulled slightly on the lever, noticed the left piston moves in and out, used a clean rag to remove the excess fluid, and it seems to have done the job.
Last edited by Winfried; 10-24-21 at 07:03 AM.
