Terrible brake squeal help

[mynydd]

Hi, Any tips to stop the disk brakes on my boarded ADV 8.9 from making such a horrendous noise that the bike is unrideable.....
I've cleaned the rotors and pads..... with emery paper and disk cleaner..... still the same noise. It seems to have got worse after being stored in the garage for a while.
the brakes are Shimano RS405 hydraulic disc and I've been using cheap TiBike green pads, which I'm not totally convinced by.... I put new ones in, it was ok briefly then the howling started again......
Should I try better pads? and if so which ones? I did a search, thought I'd found the right ones (Shimano B01S) but they are too big, luckily they'll fit my ebike.
If anyone can help I'd appreciate it..... I'd really like to get out on some gravel tracks this summer, but the noise is making it impossible.
Thanks

 

[si_c]

Not familiar with the pads if I'm honest, but it sounds reasonable that they are causing the problem, cheap pads often do.

I'm using Noah & Theo pads on my bikes at the moment, Ceramic on the road bike and the Resin (Semi-Metallic) on the MTB, both are reasonably quiet and both give excellent braking performance. They're also surprisingly cheap cheap cheap (~£13 for two pairs).

Also worth checking is that your caliper is aligned properly, the rotor should be centered and square between the pads so not at an angle front to back. or side to side. If it's a problem that has developed over time and you haven't touched the caliper or rotors then it's most likely the pads.

Get some good disc brake cleaner or Isopropyl alcohol cleaner and a very clean microfibre cloth, drop the wheel out and clean the rotor, then clean it again making sure that you keep rubbing the rotor until nothing comes off. Then replace the pads, put the wheel back in and bed the new pads in - a good plan is accelerate to a good speed and then brake until almost stopped then repeat about 10 times or until the braking performance is good.

 

[si_c]

Also forgot to add, those calipers are from the Shimano Road series, so you need road pads, fortunately they are all the same, so K or L pads (K03s/L03a or possibly K03c/L03c which are sintered pads, but if unsure don't get these as your rotors may not be suitable).

Personally I'd opt for the Resin or Semi Metallic pads as they tend to be quieter at the expense of wearing down a bit quicker. Sintered pads deal with heat build up better and I've found are generally preferable in wet or muddy conditions as they last longer but they can squeal and not all rotors are suitable as they wear those quicker too being much harder.

 

[Littgull]

Hi, Any tips to stop the disk brakes on my boarded ADV 8.9 from making such a horrendous noise that the bike is unrideable.....
I've cleaned the rotors and pads..... with emery paper and disk cleaner..... still the same noise. It seems to have got worse after being stored in the garage for a while.
the brakes are Shimano RS405 hydraulic disc and I've been using cheap TiBike green pads, which I'm not totally convinced by.... I put new ones in, it was ok briefly then the howling started again......
Should I try better pads? and if so which ones? I did a search, thought I'd found the right ones (Shimano B01S) but they are too big, luckily they'll fit my ebike.
If anyone can help I'd appreciate it..... I'd really like to get out on some gravel tracks this summer, but the noise is making it impossible.
Thanks

I can empathise. I've got the same problem with my wife's e-mtb. Scrupulous cleaning and the fitting of new pads etc have failed to resolve. Though the bike is now nearly 4 years old, it's only done 1800 miles from new and virtually none of that on highly technical surfaces! It's now been in my LBS since last October unable to source the required new discs due to worldwide parts shortages. The LBS owner is beside himself with the volume of uncompleted repairs he has still outstanding due to the impossibility of sourcing the parts!

 

[Sterlo]

Agree with the recommendations for resin pads if possible, I've tried sintered before, they didn't seem to last any longer and made a hell of a noise. Resin are also easier to "re-surface" I find, like the op states, a quick rub with wet & dry and brake cleaner/rubbing alcohol and good as new. Would recommend rubbing alcohol as a cleaner, a litre for under £10 as opposed to £5 for a small can of brake cleaner where you lose most of it in the air.

 

[shinyspokes]

So I offered to help a friend whose Shimano disc brakes were making the worst noise imaginable and juddering - having had successes on my own with combos of new pads/ emery cloth on discs and various cleaning substances; I tried changing the pads/ aligning the calipers/ cleaning the disc/ bleeding the line and even put on an old disc to see if that improved things - none of that made them any noticeable difference. As I was running out of time and they needed the bike back they took it into the LBS - who changed both the disc and pads at the same time and sorted it! Next time I think I'll cut my losses and if the simple fixes won't work will change both myself.

 

[sleuthey]

I had a near new Boardman HYB 8.8 where the disk brakes were very loud in the wet. I spoke to a friend who said his did the same. So I can’t offer a solution but can say it’s probably not faulty.

 

[mynydd]

thanks for all the help..... finally the issue is resolved. it appears I was using metal based pads on rotors that only like resin......

 

[si_c]

thanks for all the help..... finally the issue is resolved. it appears I was using metal based pads on rotors that only like resin......

Good to know you've found a solution, despite their sometimes mixed reputation I've never had a problem with properly set up disc brakes.

 

[mynydd]

Good to know you've found a solution, despite their sometimes mixed reputation I've never had a problem with properly set up disc brakes.

No, me neither…. Am a complete convert, all three of my bikes have hydraulic discs and I love them, and the simplicity of installing and servicing. The issue was hard to find pads…. So I ended up with the wrong ones by mistake…..

 

[si_c]

No, me neither…. Am a complete convert, all three of my bikes have hydraulic discs and I love them, and the simplicity of installing and servicing. The issue was hard to find pads…. So I ended up with the wrong ones by mistake…..

I know that one, I have two different sets of the wrong brake pads, I've got some G03s pads which I was assured by a guy in a LBS in Scarborough would work. They don't.