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Frankenbrakes and brake improvement discussion

Flo33

Turbo Monkey
Mar 3, 2015
2,068
1,307
Styria
Buddy had them on his Sunday and I remember bleeding them every fucking time for him we went to Schladming or Maribor coz he was a double left handed all thumbs dude. I hated them for real.
 

Andeh

Customer Title
Mar 3, 2020
1,026
995
Goddamnit, I found a flaw with Dominions. I was building up my new frame, and discovered I didn't have any spare hose barbs/compression fittings. I've got some on order now, but the problem with using smaller brands like this is that there's no shops in the area that carry their small parts. So now I have to stare at my new bike sitting in the stand with the rear brake hose disconnected.
 

troy

Turbo Monkey
Dec 3, 2008
1,013
750
Took those 1gen Code calipers apart. Dirty goo inside... no wonder pistons didnt want to retract.
1677104662906.png


I've ordered new seals compatible with mineral oil, so I can use mineral oil and shimano levers. Will report later next month probably. If not, something went horribly wrong, and you should consider me dead.
 

sundaydoug

Monkey
Jun 8, 2009
611
275
Question for all you Dominion A4/T4 guys. How have you managed to keep the pad spreader clips from rattling in the calipers? I got a fresh set of brakes installed and set up this weekend took them for a ride, and they are excellent. But the spreader clip rattling through tough terrain is driving me nuts.
 

Andeh

Customer Title
Mar 3, 2020
1,026
995
Question for all you Dominion A4/T4 guys. How have you managed to keep the pad spreader clips from rattling in the calipers? I got a fresh set of brakes installed and set up this weekend took them for a ride, and they are excellent. But the spreader clip rattling through tough terrain is driving me nuts.
I gently bend them apart (in the center, where the bolt goes through) with a flathead screwdriver when I first install the brakes.
 

Da Peach

Outwitted by a rodent
Jul 2, 2002
13,683
4,912
North Van
Question for all you Dominion A4/T4 guys. How have you managed to keep the pad spreader clips from rattling in the calipers? I got a fresh set of brakes installed and set up this weekend took them for a ride, and they are excellent. But the spreader clip rattling through tough terrain is driving me nuts.
I haven’t run into that problem. Stuff a little chunk of neoprene in under the retention bolt?
 

toodles

ridiculously corgi proportioned
Aug 24, 2004
5,520
4,771
Australia
Question for all you Dominion A4/T4 guys. How have you managed to keep the pad spreader clips from rattling in the calipers? I got a fresh set of brakes installed and set up this weekend took them for a ride, and they are excellent. But the spreader clip rattling through tough terrain is driving me nuts.
Mine aren't rattling? Probably just try to bend the spring for more tension?
 

sundaydoug

Monkey
Jun 8, 2009
611
275
I haven’t run into that problem. Stuff a little chunk of neoprene in under the retention bolt?
I was gonna try that, but I reached out to Hayes and asked them about it. They told me to carefully pry the spring apart a little bit and put it back, that seems to help in most cases. Gonna give it a shot and see how it goes.
 

sundaydoug

Monkey
Jun 8, 2009
611
275
Mine aren't rattling? Probably just try to bend the spring for more tension?
They feel fantastic, but during the ride I thought maybe it was the cables rattling against each other or I was hearing/feeling something that wasn't really there. Finally I stopped and felt all around the hub/wheel/brake caliper and sure enough I could easily move that retention spring around and that was the sound.
 

toodles

ridiculously corgi proportioned
Aug 24, 2004
5,520
4,771
Australia
They feel fantastic, but during the ride I thought maybe it was the cables rattling against each other or I was hearing/feeling something that wasn't really there. Finally I stopped and felt all around the hub/wheel/brake caliper and sure enough I could easily move that retention spring around and that was the sound.
My buddy who got them first had a rattle with the sintered pads when he fit them, but not the organics. Wonder if it was just the spring causing it. My sintereds didn't rattle so I'd put it down to a bad fitting set of pads.
 

6thElement

Schrodinger's Immigrant
Jul 29, 2008
15,985
13,242
Blob of thick grease on the bolt area will soon stop you worrying about the noise from the pads rattling.
 

Happymtb.fr

Turbo Monkey
Feb 9, 2016
1,919
1,271
SWE
I found a nerdy mechanic (Brad Kelly) on insta sharing some tricks to improve braking

Pads' squareness

New pads prep

Shaving Sram brake pads

Straighten rotor

Bleed port at the highest for the caliper too

Facing brake mounts

Caliper maintenance

Shimano pad spring
 

konifere

Monkey
Dec 20, 2021
532
661
^^^ me too, although the subtitles switched between English and German for me..

Anyone see the purple Hayes? Those look spiffy.
JensonUSA had the purple version on its website a few days ago but they're gone now.
 

ebarker9

Monkey
Oct 2, 2007
850
243
Anyone ever have leak issues with a MT5 caliper? Finally got out for the first ride of the season and noticed some noise and lack of power from the front. When I got back, I noticed that the whole caliper/pads are covered in an oily grime. I've cleaned everything up and confirmed that the fitting and bleed port are tight. No obvious damage. Going to try bleeding it tonight to see if anything shows up...I don't recall there being an o-ring on the bleed port screw that could have been pinched, so struggling to come up with an explanation.
 

konifere

Monkey
Dec 20, 2021
532
661
Did you see if it was oily before the ride, or just after? Either way it sucks, but while bleeding it you might find the problem indeed. Otherwise, Magura have a 5-year leak proof warranty, so keep that in mind if you're still in that time window.
 

two-one

Monkey
Dec 15, 2013
164
142
Eindhoven, the Netherlands
Anyone ever have leak issues with a MT5 caliper? Finally got out for the first ride of the season and noticed some noise and lack of power from the front. When I got back, I noticed that the whole caliper/pads are covered in an oily grime. I've cleaned everything up and confirmed that the fitting and bleed port are tight. No obvious damage. Going to try bleeding it tonight to see if anything shows up...I don't recall there being an o-ring on the bleed port screw that could have been pinched, so struggling to come up with an explanation.
A friend of mine was complaining about an oily MT5 caliper, contaminated pads, etc.
I cleaned everything up, and sat with a magnifying glass looking at those pistons, searching for the leak... nothing!
So I cleaned everything again, and covered the whole caliper in climbing chalk, then applied pressure to lever, and behold, a leak became visible through the wetting of the chalk. It was a leak in the aluminium crimped banjo. Good luck finding that leak!
1679925878672.png
 

ebarker9

Monkey
Oct 2, 2007
850
243
Good call on the climbing chalk. I have a ton.

That front brake has always caused me issues, so I wouldn't be too surprised if there's always been a small leak, which for whatever reason showed up more obviously after sitting over the winter.
 

konifere

Monkey
Dec 20, 2021
532
661
Thanks @two-one ! I guess that's a good thing I've seen that before installing my MT5s, I'll make sure that the cable doesn't bend too much to cause stress on that aluminium connector.
 

ebarker9

Monkey
Oct 2, 2007
850
243
Cleaned everything, threw in a bleed block, dusted with chalk and clamped the lever to the bar for a few hours. No sign of anything. Guess it's possible that not enough pressure is being generated for the leak to show up, so I'll go ahead and bleed and repeat.

Fortunately if I need a new caliper they're essentially the same cost as a new brakeset, so I might as well just do that and have a spare lever and hose (if it turns out there's an issue with the caliper and I can't get Magura to cover it).
 

Jm_

sled dog's bollocks
Jan 14, 2002
19,002
9,667
AK
Chasing down micro-leaks is what ultimately turned me off from maguras...but that was a long time ago.
 

OGRipper

back alley ripper
Feb 3, 2004
10,654
1,129
NORCAL is the hizzle
Need to replace at least one piston on an SLX 7120 4-pot caliper. (Cracked and leaking.) These are the ceramic pistons that seem pretty fragile, and I'm seeing some aftermarket options, including resin, like these, supposedly an upgrade:


Any thoughts or suggestions on this (aside from tossing in the bin and getting trickstuff)? These have been surprisingly consistent and I prefer to repair rather than replace. Thanks!
 

slimshady

¡Mira, una ardilla!
Need to replace at least one piston on an SLX 7120 4-pot caliper. (Cracked and leaking.) These are the ceramic pistons that seem pretty fragile, and I'm seeing some aftermarket options, including resin, like these, supposedly an upgrade:


Any thoughts or suggestions on this (aside from tossing in the bin and getting trickstuff)? These have been surprisingly consistent and I prefer to repair rather than replace. Thanks!
@kidwoo shot his old cracked pistons across the street a couple years ago by blowing them off the caliper with an air compressor. He then replaced them with Chinesium metallic ones, which leaked straight from brand new IIRC...

EDIT: Seems like my ceramic pistons/metallic master cylinder theory as causing the dreaded wandering bite point in mid-pack-and-upper Shimano brakes still holds!
 

richgardiner

Monkey
Aug 19, 2008
224
26
Has anyone got some tips for giving the servowave piston / camshaft area a good clean and lubing to make the lever feel nice and smooth again? or any good style brushes for getting in there and scrubbing the dirt away? bit of an awkward area
 

OGRipper

back alley ripper
Feb 3, 2004
10,654
1,129
NORCAL is the hizzle
@kidwoo shot his old cracked pistons across the street a couple years ago by blowing them off the caliper with an air compressor. He then replaced them with Chinesium metallic ones, which leaked straight from brand new IIRC...
Well I successfully installed two new pistons in that SLX caliper. The new ones are made of delrin or some other resin and they came with new seals and o-rings. Wasn't too much of a hassle and seem sto work ok, at least in the stand and after a short ride (no leaks or other weirdness so far). It remains to be seen if they can handle the heat of a long sustained descent and how they survive over time. Reviews seem mixed in that regard so guess we'll see how it goes...
 

Boozzz

Chimp
Sep 12, 2019
81
85
Amsterdayummm
Man, need to vent my frustration with these Hope Tech 4 V4 brakes again. Those calipers with their oh-so-grear new and improved stainless steel pistons, they keep leaking past the piston seals, all of them. Even after Hope and myself replacing a bunch of seals and pistons.

Micro leaks, after a few rides, the brakes start to squeak slightly. Dark dirty oily rings visible around the pistons.

Just now, as a final test, I cleaned them up for the umpteenth time, sprinkled them with climbing chalk, threw in a bleed block and squeezed the lever 50 times. Sure enough, very obvious dark rings appear around the pistons, a big wet blob even on the side of one of them. What the hell, brakes are supposed to stay dry right?
 

Jm_

sled dog's bollocks
Jan 14, 2002
19,002
9,667
AK
Idk, all the goodness is in the T4 lever, so thats all im using, with the old V4s.
 

Boozzz

Chimp
Sep 12, 2019
81
85
Amsterdayummm
Idk, all the goodness is in the T4 lever, so thats all im using, with the old V4s.
Should've done the same. Still have my old V4s here as well, but figured I might as well get the 'new and improved' caliper while I was at it. Will be putting the T4 levers on my old calipers for now (no issues save for one single piston seal replacement in 7 years).

In the meantime waiting on Hope to come up with a proper solution. I mean, both calipers having pretty sweaty piston/seal interfaces, with one of the smaller pistons especially bad, must point to something more than just bad luck.
 

zebulon13

Chimp
Jan 15, 2023
8
0
hello guys,

is it possible to mix saint levers and mt520 calipers ? and if yes what sort of power can achieve this setup ?
 

troy

Turbo Monkey
Dec 3, 2008
1,013
750
Had to clean some blood off it and some tree marks off the stem face plate but its mint.

RIP @troy
ditched the idea. Had problems with the seals, as they made them with wrong geometry. Bought MT Trail Sports, slapped Trickstuff Power pads and rotors onto them. Gonna try them this season.