MT7 brake grumbling noise

[Dave_B]

I get a grumbling noise from the MT7’s. it sounds like they are shifting in position against the holes in the disc. It only happens towards the end of the braking phase when coming towards a stop.
I have re-align callipers a few time and made sure the pads are centred.
Any ideas?

 

[apac]

They are known for pad alignment issues, probably due to having 4 independent pistons. I have read the pistons can be an issue when new and can stick. I have found that the pistons don't seem to apply the same amount of movement/pressure as each other When pulling the lever. Try removing the pads and then gently pulling the lever and watch how the pistons act. Don't pull too much though, as a piston can come right out... which is what happened to me. ?. This could be a cause of the pads catching or not contacting fully And making a noise?
it has been said that allowing the pistons to come forward and then pushing them back and doing this a good few times helps stop them from being sticky. But I am no expert, this is just what I have read.

also, they are known to rattle. I have seen someone on YouTube stick some small bits of gaffer(cloth) tape to the backs of the pads and then re-installing them which worked for them.

 

[Jackware]

I have seen someone on YouTube stick some small bits of gaffer(cloth) tape to the backs of the pads and then re-installing them which worked for them.

I don't understand this as it the pistons are magnetic and the pads are also held in position by the screwed in pins.

 

[apac]

I don't understand this as it the pistons are magnetic and the pads are also held in position by the screwed in pins.

They do seem loose when in position. , I have not heard them rattle enough to become annoying.

 

[Dave_B]

They are not rattling, just grumbling when brakes are applied.

 

[apac]

They are not rattling, just grumbling when brakes are applied.

Grumbling?

 

[Dave_B]

Sounds like the pads are shuddering against the disc.

 

[apac]

It could be the pads and rotor haven't bedded properly Or are contaminated. Try sanding the rotors with sand paper and then cleaning off with alcohol cleaner.
pads will also need removing and cleaning. Many ways to do this. Some use washing up liquid and sand paper. I use a pencil style mini blow torch To burn off anything. Be careful not to touch the surface of either rotor and pads when re-installing.

 

[Dave_B]

They are new and not contaminated. There is more than enough stopping power at both ends. The noise happens only when coming to a stop after heavy braking.

 

[Dave_B]

Im going to see if it is sticky pistons as suggested above.

 

[Venlo]

I've got the same problem. Did you solve it?

 

[Dave_B]

No. I think it’s normal for them to do it.
It’s definitely pad movement caused by the discs.

 

[MBag85]

No. I think it’s normal for them to do it.
It’s definitely pad movement caused by the discs.

I get this with the race pads everytime I use them. As soon as I put in the performance or sport pads, it stops.

 

[assyd]

No. I think it’s normal for them to do it.
It’s definitely pad movement caused by the discs.

Hi Dave,

I have the same issue with my brand new Magura MT5s. Tried all sorts of things, but could not find a solution so far..
Do you have any updates? Did the grumbling noise fade away after a while or do I have to get used to it?

Thanks a lot

 

[Dave_B]

I changed back to Hopes.

 

[assyd]

That doesn't give me much hope..

I've got the same problem. Did you solve it?

Hey Venlo,
Did you find a solution?

 

[Dave_B]

Nope

 

[VWsurfbum]

I did, its all about caliper and pad spacing. caliper needs to be a little higher than initially mounted. An extra 1.5mm washer should do it but check the pad doesn't go above the disc.

 

[assyd]

I did, its all about caliper and pad spacing. caliper needs to be a little higher than initially mounted. An extra 1.5mm washer should do it but check the pad doesn't go above the disc.

Thank you so much! I will give it a shot as soon as I can!

 

[MBag85]

Thank you so much! I will give it a shot as soon as I can!

Take the pads put of the caliper.
Align the disc centrally to the caliper, this has to be 100% not 99%.
Make sure pistons are equally pushed back.
Insert pads and give it several big squeezes.
Job done.

The Maguras have to be 100% aligned or they will grind under heat/pressure.

It took me several attempts to get it right, be patient.

It is worth dropping the wheel and inspecting the pistons by squeezing lever gently to see if all 4 pistons move equally. There's a guide on magura website for sticking pistons and how to release them. Be careful not to over extend the pistons.

 

[assyd]

Thank you for your inputs.

I have cleaned the pistons so they are kinda okay. One seems to be a bit more lazy than the others but I'm not sure if this can be completely perfect.

I haven't tired aligning the calipers without the pads though. I'll give it a try. (you meant centering the caliper to the rotor right?)

Btw, i noticed that there is a thin line around the rotor that hasnt been polished by the pads that much even though the pads seems to cover the edge of the rotor.

I'm attaching a photo

 

[MBag85]

Thank you for your inputs.

I have cleaned the pistons so they are kinda okay. One seems to be a bit more lazy than the others but I'm not sure if this can be completely perfect.

I haven't tired aligning the calipers without the pads though. I'll give it a try. (you meant centering the caliper to the rotor right?)

Btw, i noticed that there is a thin line around the rotor that hasnt been polished by the pads that much even though the pads seems to cover the edge of the rotor.

I'm attaching a photo

View attachment 73232

Yes center the caliper to the rotors.

By the looks of that picture, you're not using the full surface of the rotor. What size rotor is it and what's the post to post or adapter you're using?

 

[assyd]

Yes center the caliper to the rotors.

By the looks of that picture, you're not using the full surface of the rotor. What size rotor is it and what's the post to post or adapter you're using?

Front: 203 mm Magura Storm HC rotors, QM42 magura adaptors, Fox 34 Rhythm fork

Rear: Same rotor, QM 9 adaptors, Santa Cruz Chameleon 2018 frame

I already replaced the stock pads with the one pad / piston performance p8 pads. The stock pads made the same noise.

I chose the adaptors based on the official charts and when you look at the brakes the pads seems to cover the discs properly. But I'll check it again and attach another photo as soon as I can.

Not my video, but I experience the same thing:
I tired the trick described in the video (applying tape) and it helped a lot, but i dont think this is a proper solution as the tape can probably melt on long descends etc.

Thank you for your time again. I really appreciate

 

[MBag85]

Front: 203 mm Magura Storm HC rotors, QM42 magura adaptors, Fox 34 Rhythm fork

Rear: Same rotor, QM 9 adaptors, Santa Cruz Chameleon 2018 frame

I already replaced the stock pads with the one pad / piston performance p8 pads. The stock pads made the same noise.

I chose the adaptors based on the official charts and when you look at the brakes the pads seems to cover the discs properly. But I'll check it again and attach another photo as soon as I can.

Not my video, but I experience the same thing:
I tired the trick described in the video (applying tape) and it helped a lot, but i dont think this is a proper solution as the tape can probably melt on long descends etc.

Thank you for your time again. I really appreciate

Use this link


That disc is about 3mm out, my pads are at the top of the disc.

Double check the adapters are correct, you can't use a 200mm on a 203mm disc

 

[VWsurfbum]

See above for my comment, a couple of washers. that will get the pads sitting correctly on the disc.

 

[MBag85]

What forks do you have?

Double check they're 160mm and not 180mm.

Is the adapter installed the correct way round, the arrow should face up.

The QM42 takes a 160mm to 203mm.

The QM44 takes a 180mm to 203mm.

 

[assyd]

I double checked and the adapters seems to be correct. They are mounted properly. I don't think this needs extra washers.. :/

 

[MBag85]

I double checked and the adapters seems to be correct. They are mounted properly. I don't think this needs extra washers.. :/

View attachment 73312

View attachment 73313

Something isn't adding up.
The picture of the rotor shows insufficient height of the pads and would suggest spacers are needed or incorrect adapter.

The caliper pictures look like they're in-line with top of rotors, maybe a bad angle?
Do you have any 1.5mm spacers to try? You'll need one on each side of caliper to raise it 3mm.

Are the adapters flush with frame?
Maybe a shot of adapters and calipers and side shot with rotor in?

 

[All4Fun]

Ever done a serious break in, everything seems well adjusted, but i miss a sharply delineated trace at the bottom and top, looks pretty new.
And are your brakes feeling hard, air in the system makes you loose braking power and the pistons can't be pulled back maximum.

 

[Just get out there!]

I get a grumbling noise from the MT7’s. it sounds like they are shifting in position against the holes in the disc. It only happens towards the end of the braking phase when coming towards a stop.
I have re-align callipers a few time and made sure the pads are centred.
Any ideas?

Similar issues. Sent video to Magura tech and was told there's an alignment issue and the mounting posts need to be re-faced. Waiting for refacing tool to come in so I'll see how it goes.