Saint brakepad issues

[OlaGB]

Struggling with my saint brakes.. Merida 900E 2019.
Well atleast the rear one..

At first, both front/rear squealed, and was getting weak. Stock brakes at this point, resin pads (the very first set on the bike, never changed)
Pulled out pads, cleaned with dishwash soap, rubbed together in water and rinsed with water.
Then cleaned rotors with brakecleaner, then rubbed them, soapwashed and rinsed in water.
Bedded in and voila, great brakes and no squeal.

Until next ride... No changes done, only sitting for 2 days in a warm garage. Rear brake felt weak, and squealed. Front was good.
Cleaned the rotor again, changed to new pads (stock shimano resin). Good brakes again, for 2 rides... Back to the bullshit on rear brake, front is good. (Not cleaned bike with any soap/degreaser at this point, only water. No chance of contamination as i can understand.)

Strange though;
If i throw water at my pads and rotor, brakes are _great_ ! When they dry up, they are shite again. (Front is still good).

Bike has only 1200km on it, first set of pads still wasnt worn out at all, maybe 50%.
Cant se any leaks at all from calipers, and i`ve even changed fluid and bled both brakes properly.

I am by no means technically challenged. I work as a technichian on high tech equipment (ROV`s in oil industry), and been wrenching bikes and cars for 30 years as hobby.
But this is getting very frustrating now.

Anyone got any suggestions?
Ordered ceramic pads from Discobrakes that i plan to test next.

 

[Zimmerframe]

Bump ...

and in the meantime .. are you using any aerosol lubes or cleaners anywhere near the rear which could possibly be getting on the disk ?

Which disks and sizes are they ?

and for the 1/1000000 chance .... have you bled the rear.

 

[Gary]

Where and how do you ride? And do you drag your rear brake a lot?
Tempted to advise you to stick sintered pads in (thinking you may be glazing the organics)
Are you 100% sure your caliper pistons are not leaking? It's a pretty common fault with Shimano brakes.

 

[Gary]

Pulled out pads, cleaned with dishwash soap, rubbed together in water and rinsed with water.
Then cleaned rotors with brakecleaner, then rubbed them, soapwashed and rinsed in water.
Bedded in and voila, great brakes and no squeal.

Thinking they were contaminated?

If they are, fixes like this (and setting light to or sticking the pads in the oven etc.) never solve it. (occasionally it will seem improved, but only for a very short while)

 

[Flatslide]

I had a similar issue with the front M820 on my Remedy. I'd clean the pads, scuff the rotor with 240 grit on a flat surface, brake would be mint for a short time and then it would start howling again, behaving like it was glazed. I tried new pads with the same result. In the end I replaced the rotor (203 ice tech) and Shimano ice tech metal pads with the same, bled it again and finally all good. That rotor ended up on the rear of my PowerPlay with the Shimano metal pads the bike came with and I wore it out after many miles of trouble-free service. No idea what the issue was, never struck it before or again.

 

[OlaGB]

No oils or solvents anywhere close to the new pads or rotor, 100% certain..

I trailride both on flat and hills, not feathering brakes, but ofcourse i dont always go 100% on them. But i really dont think i`m glacing them constantly «filing them», i do ride kinda agressive.

Bleeding done properly, without pads in. Cleaned calipers proper afterwards.

I can not see any signs for leaks, no matter where or how i look at caliper/pads..

 

[Bonz]

Looks like you’ve tried all these suggestions already.
I have 900e as well.
Did have to bleed the brakes on first pad change.
Recently replaced rotors and pads. Because I was so slack I didn’t notice the small grooves worn in the rotors thinking they would last for years. Yikes.
Still use ceramic pads, all good and no noise.

 

[ImSundee]

Sounds like glazed pads from what I'm reading, try some with more of a metalic compound like sintered.

 

[OlaGB]

What i find very strange, is that if i pour water onto the caliper/pads, the brakes immediately works alot better.
5-10 medium braketests later, they start to get weak again.

 

[Zimmerframe]

What i find very strange, is that if i pour water onto the caliper/pads, the brakes immediately works alot better.
5-10 medium braketests later, they start to get weak again.

This is the weirdest part of your problem !!

It suggests there's some unusual phenomena going on which we're missing..

Are your pistons sticking and the water is working as a lubricant ?

Is the disk warped and the moisture is reducing friction, but in some weird twisted way that means you actually end up with more friction once it's got past the initial "not working zone" or you've invented a new ground effect none contact braking system ?

Could the caliper be slightly out of alignment ?

The glazing sounds the most likely, but the moisture test doesn't make sense. If you switch to metal/ceramic if there's some other issue at play, it may not fix it.

If you can work this out, you'll soon be a very rich man as you'll be able to create a hack for SRAM owners so they can have working brakes in the wet !

 

[OlaGB]

Yeha, maybe i should make a sprinkler system for the rear brake ?

I`ve inspected the rotor to be perfect, as far as i can tell.

Re-alligned the caliper in every way i can think of... Ended up alligning it so i clearly can tell both pads hit the rotor at the same time, so the rotor does not `bend` to any sides.. This is very sensitive to positioning, but gave no changes what so ever to my problem.

 

[Zimmerframe]

Yeha, maybe i should make a sprinkler system for the rear brake

I thought a small wet kitchen sponge zip tied above the caliper ?

It is a weird one.

With my SRAM's when they made a noise I noticed a huge loss in braking performance, presumably as they resonated. Though possibly also from the disk/pads being wet and the reduction in performance you'd expect. I tried several pad types and it made no difference.

Better performance when wet is just counter-intuitive .. unless you have female brakes ?

 

[Gary]

try some with more of a metalic compound like sintered.

This ^^

 

[OlaGB]

Yep, gotta try different types of pads next i guess.

Will try the disco cermic ones first, then probably swissstops or some other quality brand.

 

[Gary]

sintered!

SIN... TERD



You don't need to spend tons or go for fancy brands or compound mixes.

 

[Jackware]

You don't need to spend tons or go for fancy brands or compound mixes.

I've tried that idea for Xmas and birthday presents but my wife doesn't seem to be on the same wavelength...

 

[OlaGB]

sintered!

SIN... TERD



You don't need to spend tons or go for fancy brands or compound mixes.

Thing is, i`ve been googlin _alot_ about this issue the last days obviously, and from what i`ve found it seems like this is a known issue among MANY shimano users the last 5 years.
Pads seems to go weak just by sitting still for acouple weeks.
Most on resin pads, but also several on shimano sintered.

I suspect it`s the material Shimano uses, that`s why i want to go other brands.

 

[Gary]

Yeah. And shimano are nowhere near the cheapest for Saint compatible sintered pads.
Pads don't just "go weak" from sitting around unused. They sit around unused for months/years prior to their first use.

Try any brands Saint compatible sintered pads you like. If they do the same thing companies like uberbike/disco should refund you. But if they have done the same thing I'd guarantee it is not the fault of the pad material. And it's not from just sitting around.

 

[Mcharza]

Older Saint caliber seem to leak a little bit of brake fluid and the brake pads get ruined.

I have tried to clean the brake pads with sandpaper, pouring water on the brake pads. I have also cleaned the rotors with sandpaper. Doesn't help, except for a moment.

When you change to a new brake pads, clean the rotors with brake cleaner and bleed the brake, it starts working

 

[OlaGB]

Older Saint caliber seem to leak a little bit of brake fluid and the brake pads get ruined.

I have tried to clean the brake pads with sandpaper, pouring water on the brake pads. I have also cleaned the rotors with sandpaper. Doesn't help, except for a moment.

When you change to a new brake pads, clean the rotors with brake cleaner and bleed the brake, it starts working

Bike is 1y old, with stock saint brakes. 2019 model bike.

Believe me, ive triple checked for leaks, cleaned EVERYTHING atleast 10 times, also before putting in new pads.
Brakes worked GREAT for 15km after installing new pads. 1 week later, they where shite. No oil residue to be seen anywhere, bike was`nt cleaned or lube`d since before changing pads.

Latest attempt now is i cleaned everything, torched the new pads (15km on them since install), torched the rotor, rubbed everything again with 200 grit, and cleaned again with proper brake cleaner.
Rotor torching was the only new thing i added to the process now.

After bedding they seem to work as expected again now, after a 15km testride. Bike will sit another 2 weeks now before i can ride again, then i`ll know more.

 

[OlaGB]

Yeah. And shimano are nowhere near the cheapest for Saint compatible sintered pads.
Pads don't just "go weak" from sitting around unused. They sit around unused for months/years prior to their first use.

Try any brands Saint compatible sintered pads you like. If they do the same thing companies like uberbike/disco should refund you. But if they have done the same thing I'd guarantee it is not the fault of the pad material. And it's not from just sitting around.

Tell it to these guys..
XT and XTR brakes get squeal/power loss after sitting idle for 6-8 weeks- Mtbr.com

I totally agree with you, it does absolutely not sound right. And it can be some contamination crap going on, which is not visible. But there is no doubt there`s ALOT of experienced biker`s that struggles with this, that does not struggle with other type`s of brake brands..

 

[Tbar]

Had exactly the same happen to me on an old set of Zees. Couldn’t find a leak anywhere and the issue happened on both the front and rear callipers. Drove me insane. Changed pads / rotors / rebled a million times. In the end I gave up and switched brakes.

Glad I stumbled across this thread as I was close to buying some Saints for the Kenevo but this has jogged my memory and opened up the old wound!

 

[Mavik]

Struggling with my saint brakes.. Merida 900E 2019.
Well atleast the rear one..

At first, both front/rear squealed, and was getting weak. Stock brakes at this point, resin pads (the very first set on the bike, never changed)
Pulled out pads, cleaned with dishwash soap, rubbed together in water and rinsed with water.
Then cleaned rotors with brakecleaner, then rubbed them, soapwashed and rinsed in water.
Bedded in and voila, great brakes and no squeal.

Until next ride... No changes done, only sitting for 2 days in a warm garage. Rear brake felt weak, and squealed. Front was good.
Cleaned the rotor again, changed to new pads (stock shimano resin). Good brakes again, for 2 rides... Back to the bullshit on rear brake, front is good. (Not cleaned bike with any soap/degreaser at this point, only water. No chance of contamination as i can understand.)

Strange though;
If i throw water at my pads and rotor, brakes are _great_ ! When they dry up, they are shite again. (Front is still good).

Bike has only 1200km on it, first set of pads still wasnt worn out at all, maybe 50%.
Cant se any leaks at all from calipers, and i`ve even changed fluid and bled both brakes properly.

I am by no means technically challenged. I work as a technichian on high tech equipment (ROV`s in oil industry), and been wrenching bikes and cars for 30 years as hobby.
But this is getting very frustrating now.

Anyone got any suggestions?
Ordered ceramic pads from Discobrakes that i plan to test next.

I had the exact same issue but it was with metal pads. I swapped to resin and it went away

 

[lumpy]

I battled the Saint disc squeal on my home built commuter ebike and it was driving me crazy. My solution was to apply a thin layer of CRC Disc Brake Quiet to the back of the pads
I think that there were harmonic vibrations causing the squeal and not an issue of the contact patch between the pads and disc.

Now my brakes are quiet

 

[Orangie]

Seeping calipers on my Xt brakes caused similar issues

 

[Gary]

Saint disc squeal on my home built commuter ebike

Lumpy's commute.