How to fix screaming brakes?
Discussion
With Shimano hydraulic brakes the chances are that the calliper is leaking and contaminating the pads. It’s a pretty common thing with them and has been for quite a few years yet Shimano don’t seem to have resolved the issues.
Best thing to do is get a replacement calliper with new pads.
Best thing to do is get a replacement calliper with new pads.
gallopingclothespeg said:
With Shimano hydraulic brakes the chances are that the calliper is leaking and contaminating the pads. It’s a pretty common thing with them and has been for quite a few years yet Shimano don’t seem to have resolved the issues.
Best thing to do is get a replacement calliper with new pads.
Yep. Its not that easy to spot any fluid leaking either. Although they do pretty much stop working as brakes which is a good clue. The pads will look shiny and polished.Best thing to do is get a replacement calliper with new pads.
If it's back one it could be over zealous use of chain lube.
I got callipers for about £35/each on Amazon but the price varies a lot. There are various alternatives as well, cheaper mountain bike ones that look very similar but retain the pads with a split pin M6000?, 4 pot Shimano ones MT520? and 4 pot Hope ones.
I have the same issue with Shimano Ultegra Di2 brakes on a new bike that I bought this Summer.
At first both brakes worked fine, but then I changed the bar, stem and fitted new brake cables and have had issues since with horrendous brake squeal and no retardation - front and back.
So far, I've tried roughing-up the pads, cleaning the rotors with IPA and even new pads. Whatever method I try results in the brakes seeming to work ok whilst the bike is on a stand in the house, but as soon as I take it out for a ride the squeal returns straight away.
Searching the internet tells me that brake squeal is due to vibration; from where I don't know. I've checked to ensure that the rotors are flat and that they are central in the calliper.
This is the first time that I've seen that the squeal might be due to fluid leaking internally from calliper to pad, which would make sense. I didn't realise that this is a common issue with Shimano disc brakes.
I'm now at my wits end on how to resolve this, short of taking it into a dealer.
I'm seriously considering junking the Ultegra callipers and getting the 4 pot Hope ones. If I did this should I keep my current rotors or get the Hope or XTR rotors that seem to be a popular option.
TIA
At first both brakes worked fine, but then I changed the bar, stem and fitted new brake cables and have had issues since with horrendous brake squeal and no retardation - front and back.
So far, I've tried roughing-up the pads, cleaning the rotors with IPA and even new pads. Whatever method I try results in the brakes seeming to work ok whilst the bike is on a stand in the house, but as soon as I take it out for a ride the squeal returns straight away.
Searching the internet tells me that brake squeal is due to vibration; from where I don't know. I've checked to ensure that the rotors are flat and that they are central in the calliper.
This is the first time that I've seen that the squeal might be due to fluid leaking internally from calliper to pad, which would make sense. I didn't realise that this is a common issue with Shimano disc brakes.
I'm now at my wits end on how to resolve this, short of taking it into a dealer.
I'm seriously considering junking the Ultegra callipers and getting the 4 pot Hope ones. If I did this should I keep my current rotors or get the Hope or XTR rotors that seem to be a popular option.
TIA
A couple of things I've done in the past;
Use automotive ceramic brake grease on the non friction pad surfaces (where they contact the caliper body) You only need to use the smidgiest smidge!
Fit tiny cable ties to the disc spokes, making sure they don't foul anything. Fit the ties in opposite pairs on the disc spokes. These act as vibration 'dampers'.
The above cured a horrible squeal on a bike with BB7 cable disc system.
Interestingly, I've not (yet) had issues with squeal with my Shimano hydro equipped bike.
Use automotive ceramic brake grease on the non friction pad surfaces (where they contact the caliper body) You only need to use the smidgiest smidge!
Fit tiny cable ties to the disc spokes, making sure they don't foul anything. Fit the ties in opposite pairs on the disc spokes. These act as vibration 'dampers'.
The above cured a horrible squeal on a bike with BB7 cable disc system.
Interestingly, I've not (yet) had issues with squeal with my Shimano hydro equipped bike.
My Canyon Endurace with Ultegra does it on both front and rear as soon as it’s wet. Tried different pads, brake disc cleaner, cable tie trick etc. None of it makes a difference - seriously considering replacing the callipers and discs with Hope units.
Fundamentally I think the main issue is Shimano calipers consistency are s
t, mine have never felt that great since day 1. The Campagnolo discs brakes by comparison on my BMC are amazing but that bike is far too nice for the winter weather.
Fundamentally I think the main issue is Shimano calipers consistency are s
t, mine have never felt that great since day 1. The Campagnolo discs brakes by comparison on my BMC are amazing but that bike is far too nice for the winter weather. They all do that sir. But seriously, you could experiment with different pad types and materials, some combinations squeal worse than others. There is a way to silence them properly, but it’s a bit risky. Put some bike grease ( or copper grease if your feeling brave) on the piston side of the pads. But be warned, if you use too much, you run the risk of ending up effectively greasing the front of the pads, and your brakes won’t work. I tend to use it on the rear only, that way, if the rear brake suddenly stops working, you’ll still be able to stop.
Bin the existing pads. Lightly emery cloth the disc and thoroughly clean disc and calliper with preferably isopropyl alcohol (Amazon) or muck off's disc brake cleaner. Fit new pads (don't touch braking surface) and bed in the new pads - there's videos online showing how to do that. In principle it's repeated hard stops but not locking up to deposit pad material on the disc. This is a key step.
You could try and emery cloth and thoroughly clean the existing pad with isopropyl alcohol. I wouldn't bother - bin them or save for spares.
Scrupulously cleaning everything and bedding in the pads properly should fix it. Sorted mine!
You could try and emery cloth and thoroughly clean the existing pad with isopropyl alcohol. I wouldn't bother - bin them or save for spares.
Scrupulously cleaning everything and bedding in the pads properly should fix it. Sorted mine!
Edited by ian in lancs on Monday 14th December 18:47
I contaminated my rear pads with some careless application of gt85 which made the honk under braking and really lost their bite.
My solution short of buying new pads was to pop them out, give them a light sand on a block of fine sandpaper and then borrowed the kitchen blow torch and gave them a quick blast. After they had cooled they were good as new.
My solution short of buying new pads was to pop them out, give them a light sand on a block of fine sandpaper and then borrowed the kitchen blow torch and gave them a quick blast. After they had cooled they were good as new.
The fronts of my Zees have always squealled under light braking but hard stopping power is always there, and the noise goes with the effort.
The fronts of my 105s have recently started squealing too - the stopping power is there, so I just give the pads in the Zee and 105 a light sanding with some 240 grit every few weeks.
If neither worked properly I’d bin them, but they both pull up fine
The fronts of my 105s have recently started squealing too - the stopping power is there, so I just give the pads in the Zee and 105 a light sanding with some 240 grit every few weeks.
If neither worked properly I’d bin them, but they both pull up fine
As mentioned above it will be a faulty caliper which is leaking and contaminating the pads , you can’t see the leak . Especially prevalent with the old post mount calipers but can affect the new. Buy a new caliper and keep the receipt so you can return it when it inevetibly fails again.
Gassing Station | Pedal Powered | Top of Page | What's New | My Stuff