New Magura Brake squeal

[RomP]

Hi Hubbers,

 

Hope you can give some solid advice. Apologies for the long post...

 

I bought a new Magura brake set in November last year. For warranty purposes I had to have it installed by the LBS that sold me the brakes.

Installation of Magura Trail Sport brake set + new rotors = 5 November 2020

Did not ride the bike until late December ( working during year end rush)

Did pickup a noticeable squeal on the rear brake with the first ride ( 1 x loop at Wolwespruit) , but assumed it was still new....give it some time I thought

2 rides later ( 7km in total) brake squeal still persistent.

Called the LBS in January to complain and the answer was "just check what pads you have in, performance vs comfort ?? type of explanation" I was told it was probably "contamination" clean rotor or bring in the bike.

Next ride, more squeal on the rear brake, so I took the pads off, cleaned pads and rotor well with 91% isopropyl alcohol. Took it for a test around the block, still squeal.

Called LBS last week was told to bring in the bike for an assessment. If warranty issue, Magura rep will have to come out to assess. I was not to happy about that, i would have expected a " bring it in we will replace the pads  or rotor" no questions asked response but this was not the case.

 

Reluctantly again took the bike in last week. Bike was ready 2 days later and I was told the following:

Rotor contaminated( this was after I had thoroughly cleaned and only rode the bike around the block to test). Anyway, I took the mechanic's word and on the way out I also had another conversation with someone in the shop. I was asked what oil I use on the chain. I use Liqui Moly wet lube ( on all 3 other bikes we have) but was told it was bad quality oil  and may contribute to the so called "contamination". ( strange as Ive been using this chain oil on our other 3 bikes for the last year no issues) I was told the bike was tested an all is good. They simply cleaned the brakes. That last last Wednesday.

Took the bike for a test around the block on Friday...guess what, still a small noticeable squeal on the rear brake.

 

NOTE: No issues with the front brake , all working well.

 

I have 2 other bikes running different year model shimano XT brakes and my own ( prior to changing over to Magura for a better modulation experience) and non of these brakes ever had this squealing problem. We ride the same trails, all have the same riding style, so i seriously doubt the "contamination" explanation. 

Besides me making a big issue out of this, is there someone else having a similar issue that has resolved this ? Is there someone with some sound advice on what else to try. Do I spend  another R450 on a new set of pads just to prove a point ? 

 

[Steady Spin]

What break-in procedure did you follow when the system was brand new? 

[RomP]

What break-in procedure did you follow when the system was brand new? 

I would have assumed the LBS that installed my brakes would have done that. I did however on my own do a series of about 20 gradual stops for both front and rear giving time between every few stops to cool down. That how i normally do it for all my new brakes. 

Edited February 22, 2021 by RomP

[Steady Spin]

I would have assumed the LBS that installed my brakes would have done that. I did however on my own do a series of about 20 gradual stops for both front and rear. 

 

Your LBS will only fit and make sure the bleeding is done correctly. Maybe some will bed the brakes in. 

 

What has never failed me was getting the bike up to a good speed and climbing onto the brakes as hard as you can. 

 

Repeat 10 times for the front and 10 times for the rear. Don't do it together. Really go at it. 

 

You could try and sand down the pads a bit and redo the bedding in process. 

 

Do you know what material the pads are?

[shaper]

I would have assumed the LBS that installed my brakes would have done that. I did however on my own do a series of about 20 gradual stops for both front and rear giving time between every few stops to cool down. That how i normally do it for all my new brakes. 

Gradual stops, you have probably glazed the pads, should be hard breaking to scrub break pads... sand the pads to get rid of glazing

 

Edited February 22, 2021 by shaper

[Jono]

The steps I would take to try resolve this:

 

1. take out pads and inspect for contamination

2. put some high grit 1200 or so sand paper on a flat surface facing up and gently sand the pads taking off a very small amount, clean afterwards with isopropyl

3. clean rotor with isopropyl

4. bed them in by doing some hard braking a few times in the road

[Bomberman]

I would have assumed the LBS that installed my brakes would have done that. I did however on my own do a series of about 20 gradual stops for both front and rear giving time between every few stops to cool down. That how i normally do it for all my new brakes. 

sitting with same problem and it drives me nuts. Have you checked the brake pressure, could also be that the calipers are not clamping down hard enough.

[RomP]

Gradual stops, you have probably glazed the pads, should be hard breaking to scrub break pads... sand the pads to get rid of glazing

 

What i mean by Gradual stops is not flat our over the bars or locking up the rear brakes. Maybe I should have re phrased it..Gradual hard braking. I did however check, no glasing. Im sure LBS would have mentioned this when they checked last week....I hope..

Edited February 22, 2021 by RomP

[RomP]

Your LBS will only fit and make sure the bleeding is done correctly. Maybe some will bed the brakes in. 

 

What has never failed me was getting the bike up to a good speed and climbing onto the brakes as hard as you can. 

 

Repeat 10 times for the front and 10 times for the rear. Don't do it together. Really go at it. 

 

You could try and sand down the pads a bit and redo the bedding in process. 

 

Do you know what material the pads are?

I just would expect a LBS to have done this as a service for forking out R6k + for the brakes. The pads are apparently the black "performance" pads. I just don't see why i have to modify / sand a brand new set of pads.Just now ill be accused of damaging the pads...

[RomP]

sitting with same problem and it drives me nuts. Have you checked the brake pressure, could also be that the calipers are not clamping down hard enough.

Are you finding this problem with new brakes and the rear caliper ? In my case I assume the pressure is 100% as the brakes are brand new and installed by specialists, thus me suspecting pads / rotor issue.

[dasilvarsa]

I use Shield Car Wash neat and a Nail Brush to decontaminate Disks. (off the Bike)

You have to Work Both Sides for a long time to get it all out, rinsing in between.

The Contaminant (oil) is not only on the Surface it is also in the holes of the disk.

I Avoid Oil Based chain lubes.

Riding a lot on the road also causes disk contamination.

Your The Problem Might or Might Not be Disk Contamination but it easy to eliminate.

Alcohol dilutes the Oil. Alcohol Evaporates Oil Stays Behind.