Rip

Bore looks ok, only thing we can think of right now is that the seals are slowly getting damaged every time they pass the bleed port up until a point where they can't take the pressure any more and just fail.

Bore looks ok initially but he's going to get an endoscope down there later. I made a mistake earlier, the bike didn't come from Tarty in the end because it was bought at the time when everyone was having major stock issues.

Not sure, I'll ask my mate to take a look and get back to you.

So what causes a seal to blow like this (and in two places) after a very low speed over the bars crash? The lever being pushed in to quickly?

It's a mates lever that it's happened to, he bought the bike from Tarty last year I believe, I'll pass the message on.

Confirmed blown seal on piston in lever. It wasn't even a hard or fast crash, just a slow over the bars. These plastic MT levers are rubbish. I'm personally switching to Hayes Dominions before this happens to my set.

Thanks, possibly just needs more attention when bleeding then, either that or damaged seal on main piston?

Thanks man, any idea exactly what fails inside when they take a knock?

Not mine but a mate went over the bars earlier and now his back brake doesn't work at all, lever to bar with zero resistance. No visible damage on the outside, no oil leaking anywhere, everything done up tight etc. Tried a fast bleed then a full bleed but exactly the same. We've decided he probably needs a new lever because the internals are not serviceable but does anyone have any idea what could have happened as I'm curious? He's going to take it apart but hasn't as of yet. I'm wondering how an internal part got damaged so badly without any significant visible damage. Aso I assume nowhere sells the actual master cylinder without the HC3 lever blade? Not having to buy the blade would take a chunk out of the £98. Aso anyone know if an MT5 lever would work with an MT7 caliper?

Good tip about the rear brake.

Thanks dude, I'll give it another go then while bearing those tips in mind.

This is probably a clearer view of the first move, I can't seem figure out where the height comes from:

I've borrowed these two clips from @Ali C's YT channel so hopefully you don't mind but if you do just DM me and I'll remove them Move 1 - Not exactly sure what it's called but it's essentially a large side hop starting on the back wheel and also landing on the back wheel, the highest I can do these is about 12 inches lol so I need to know where the power comes from, is it a big squat and leg muscle burst or a very well timeed pedal kick, or both? Move 2 - Again I'm not all up the lingo so not sure what the cool term for this is but it's basiaclly swapping the front wheel for the back wheel using just the tinyiest bit of forward momentum, it's almost static but not quite. I also ride a Fourplay and struggle with these becasue it always feels like the back wheel is far too close to the obstacle to be able to get it up there without it bouncing of off the face of the obstacle. I pretty much can't even do these at all because of that reason, i usually end up doing exactly that and bouncing the back wheel off of the obstacle so I clearly have no idea how this technique works or where to start with it. I can happily pedal kick up something this size but i have to start a little further back to give myself the room to get the back wheel, as soon as I try to do it with front wheel already on top of the obstacle it all goes wrong.

I might give that a go then.

Mine isn't that bad luckily but sometimes when I'm just sat on the bike chilling some small movements cause the brakes to squeak and whine a bit and it annoys me. No amount of caliper alignment fixes it so it must be the pads are not returning, maybe I'll see if I can bodge together some return springs for them.

I was told to use whatever brake fluid your brakes use so I used a bit of Royal Blood. to be honest though it didn't make much difference, I was hoping the pads would return a bit more and give me a little more pad clearance. MT7s are known for little/no pad clearance so I guess that's my problem.

Probably because there aren't any trials specific brake cleaners out there because the whole disc brake trials market is very small compared to other cycling disciplines. Trials bikes don't get any heat into the brakes so can't burn off any residue left by cleaners, a dedicated trials cleaner would probably need to be formulated that didn't leave a residue. That's my best guess anyway.

This has been my assumption so far, to be safe then I'll just carry on avoiding any fluid of any kind except for water.

My Isopropyl is 99.9% apparently. If I do get any contamination I'm just binning the rotors and pads and replacing them because I've never successfully managed to save any. Just thinking more along the lines of general maintenance and cleaning.

Talking Magura disc brakes here, I'm scared to death of getting any fluids on my rotors and pads (other than water) for fear of contamination because I've had my fair share of that in the past and it's a pain in the ass. But sometimes I feel like my brakes could do with a clean so can anyone confirm if there are any brake cleaners that are 100% safe for use on Magura discs and pads specifically on a low rpm trials bike that never puts heat into the brakes? I use isopropyl when cleaning the calipers after bleeding but wondering if anything is actually rotor and pad safe.

Their attitude with you regarding support is a bit of a worry, I guess the best thing to do is buy them through a decent bike shop so at least there is some backup there if you end up with a duff set.

Interesting, they must be quite something if you're happy with them because you've probably tried more brakes than most of us lol Maybe it simply is just a quality control issue then and a bit of a lottery as to how good any particular set will be.

Some useful info there! Wonder if @Ali C has had any such issues?

Thanks, that actually makes a lot of sense thinking about it lol

Anyone know what size packer I need to use between the pistons in order to get them to poke out enough for lubing and cleaning (with pads removed) but not too far that they pop out and cause me all manor of bad times?