Shimano hydraulic sticky pistons; HELP!
11-27-22, 03:58 PM
#1
Curmudgeon
Thread Starter
Join Date: Nov 2018
Location: Triangle NC
Posts: 336
Bikes: Specialized Diverge Comp
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 157 Post(s)
Liked 32 Times
in
28 Posts
Shimano hydraulic sticky pistons; HELP!
I'm at my wits-end to get my front brake piston to release back into the caliper when I release the brake leaver while riding. I've cleaned it 7-8 times following Park Tools (and Bike forums) advice, and all other recommendations, but to no avail
When riding and I apply front brakes and release the handle the brake squeal is excessive. I always have to pump the lever 4-8 times to work it lose and the squeal goes away, but that is no way to ride. I'm considering buying a rebuild kit to replace the pistons and seals but don't see any for sales nor do I see that as a commonly recommended procedure to fix sticky pistons. I've tried everything I know or which has been recommended. HELP.
Any advice?
When riding and I apply front brakes and release the handle the brake squeal is excessive. I always have to pump the lever 4-8 times to work it lose and the squeal goes away, but that is no way to ride. I'm considering buying a rebuild kit to replace the pistons and seals but don't see any for sales nor do I see that as a commonly recommended procedure to fix sticky pistons. I've tried everything I know or which has been recommended. HELP.
Any advice?
Last edited by rbrides; 11-27-22 at 04:06 PM.
11-27-22, 04:43 PM
#2
Senior Member
Join Date: Jul 2019
Location: In the south but from North
Posts: 700
Bikes: Turner 5-Spot Burner converted; IBIS Ripley, Specialized Crave, Tommasini Sintesi, Cinelli Superstar, Tommasini X-Fire Gravel
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 406 Post(s)
Liked 389 Times
in
219 Posts
I'm at my wits-end to get my front brake piston to release back into the caliper when I release the brake leaver while riding. I've cleaned it 7-8 times following Park Tools (and Bike forums) advice, and all other recommendations, but to no avail
When riding and I apply front brakes and release the handle the brake squeal is excessive. I always have to pump the lever 4-8 times to work it lose and the squeal goes away, but that is no way to ride. I'm considering buying a rebuild kit to replace the pistons and seals but don't see any for sales nor do I see that as a commonly recommended procedure to fix sticky pistons. I've tried everything I know or which has been recommended. HELP.
Any advice?
When riding and I apply front brakes and release the handle the brake squeal is excessive. I always have to pump the lever 4-8 times to work it lose and the squeal goes away, but that is no way to ride. I'm considering buying a rebuild kit to replace the pistons and seals but don't see any for sales nor do I see that as a commonly recommended procedure to fix sticky pistons. I've tried everything I know or which has been recommended. HELP.
Any advice?
Also, before you do that, make sure to push the pistons back with something like the park tool - which I highly, highly recommend, and remove the pads before doing any bleeding, etc.
But if you can't get any of that to work, and the system is not too old, trying getting it warranted.
11-27-22, 06:04 PM
#3
Curmudgeon
Thread Starter
Join Date: Nov 2018
Location: Triangle NC
Posts: 336
Bikes: Specialized Diverge Comp
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 157 Post(s)
Liked 32 Times
in
28 Posts
Pistons that won't retract sometimes indicates air behind the piston. Have you tried re-bleeding the system? Even with Shimano systems, I like to "push" from the bottom and force fluid into the cup. Often, that releases the air and get the piston moving correctly.
Also, before you do that, make sure to push the pistons back with something like the park tool - which I highly, highly recommend, and remove the pads before doing any bleeding, etc.
But if you can't get any of that to work, and the system is not too old, trying getting it warranted.
Also, before you do that, make sure to push the pistons back with something like the park tool - which I highly, highly recommend, and remove the pads before doing any bleeding, etc.
But if you can't get any of that to work, and the system is not too old, trying getting it warranted.
