Magura MT7 - losing pressure

[p3eps]

I've recently swapped all my components from my Levo SL 1.1, to a Levo SL 1.2 frame - including my MT7's.

When tightening up the clamp on the front one after bleeding, the driver kept spinning despite me always tightening to the correct torque. When I removed the screw, half of the composite material was stuck in the thread.

I needed to order a new longer brake hose for the rear, and new pads for the rear anyway - so it made more sense to buy a whole brake rather than just a lever.

I got it at the very end of May, fitted the new hose / caliper to the rear, and the new lever to the front.
Bled them both, and got them to a nice pressure level.

On my first 'real' ride (not messing about outside the house), the front brake went spongy, and was virtually useless after my first downhill run. I just assumed I'd missed some air pockets, so bled it again ready for the next weekend.
Next weekend, same thing happened again. I pushed some fluid in the top bleed screw with a syringe, and it seemed rock solid again.

The next ride, the same thing happened... within 20 mins of hard braking, the lever could be pulled right against the bar.
Another full bleed, and it did the same again on the next ride. This time, I was examining the lever / caliper straight afterwards, and noticed there was fluid around the bottom bleed screw (underneath the brake - I assume it has 2 for left / right side use?). Anyway, when home, I realised that the bottom bleed screw wasn't particularly tight, so did it up to the Magura 0.5Nm spec. Re-bled the brake again, and it seemed great. Problem solved... or so I thought.

Been out this morning on a big ride, and pretty much the same again - albeit it took a lot longer for it to get the the lever touching the bar.... but within a few downhill runs, the brake was getting softer and softer. Not quite as obvious this time, but again there was fluid under the lever.

Part of me wants to contact the shop where I got it (online) and see what their thoughts are. Is this going to be a warranty issue since the lever is only 5 weeks old? The other part of me thinks they'll say I've either caused it, or the brake isn't covered by warranty as I've effectively 'split' the lever / caliper by using one as front, and one as rear.

Has anyone had this before? I could try a bit of locktite on the bleed screw and see if that helps, or maybe even a tiny bit of PTFE tape? I'm not even 100% sure the fluid is actually coming from the bleed screw though - it just appears to be underneath.

It's really annoying, as I'm wanting to enjoy my new bike (frame!) and test out it's limits... but every time I'm out I end up having to take it easy as I have no front brake!

 

[Shjay]

Check to see if there is any oil on the hose, around where it joins to the lever it’s might not like the olive & barb used or the 8mm bolt into lever could be nipped up a bit more

 

[Shjay]

Other idea being flip flop designs to swap levers over so bleed screw is on top side of the lever

 

[p3eps]

Check to see if there is any oil on the hose, around where it joins to the lever it’s might not like the olive & barb used or the 8mm bolt into lever could be nipped up a bit more

I just did that 2 mins ago!

Other idea being flip flop designs to swap levers over so bleed screw is on top side of the lever

Last resort! My back brake pressure is so good, I don’t want to touch it.

 

[Shjay]

This technique does work not hadoil seeping from bleed screw before only hose at lever or caliper end. Mine have been pulling to bar sometimes where run aftermarket (Ali Express)lever with Magura caliper

 

[RAG]

Check to see if there is any oil on the hose, around where it joins to the lever it’s might not like the olive & barb used or the 8mm bolt into lever could be nipped up a bit more

^^ this!

Had this a few times, the 8mm hose bolt for compressing the olive is 4nm, that’s actually a lot tighter than feels comfortable with all that carbotecture plastic!

 

[p3eps]

This technique does work not hadoil seeping from bleed screw before only hose at lever or caliper end. Mine have been pulling to bar sometimes where run aftermarket (Ali Express)lever with Magura caliper

I’ve tried that trick with the hole in the syringe before, but it must’ve been a few years ago. I’ve been doing the 2 syringe method the last few times - but this looks a bit easier.

 

[p3eps]

^^ this!

Had this a few times, the 8mm hose bolt for compressing the olive is 4nm, that’s actually a lot tighter than feels comfortable with all that carbotecture plastic!

My olive should already be compressed, as my front hose / caliper are 3 years old. It’s only the lever that’s changed. I did tighten it a little more though.

 

[Shjay]

My olive should already be compressed, as my front hose / caliper are 3 years old. It’s only the lever that’s changed. I did tighten it a little more though.

Maybe olive was all good for old levers but not the new ones. It’s just working out what’s changed. Pull off cover to 8mm nut & pull lever few times, any slight oil on hose?

 

[Stihldog]

I’ve only installed about 6 MT7 brake systems. One thing that was suggested to me was to lightly wipe some grease around the olive (new) before it’s installed. Always use a new olive and barb for installs.

This small angle thingy is available through Magura also. The new brake hose angle cleans up the cockpit a bit.

Sounds like you’re leaking fluid somewhere. Bleed screw first …then every other connection and piston.

 

[p3eps]

Maybe olive was all good for old levers but not the new ones. It’s just working out what’s changed. Pull off cover to 8mm nut & pull lever few times, any slight oil on hose?

Could try chopping the olive off and putting a new one on. I think there’s enough excess on the hose.

I’ve only installed about 6 MT7 brake systems. One thing that was suggested to me was to lightly wipe some grease around the olive (new) before it’s installed. Always use a new olive and barb for installs.
View attachment 119339
This small angle thingy is available through Magura also. The new brake hose angle cleans up the cockpit a bit.

Sounds like you’re leaking fluid somewhere. Bleed screw first …then every other connection and piston.

That looks good - will have to see if I can find a couple of them.

 

[Stihldog]

If the brake line and barb are not held securely in place during installation, the final seat will not be correct when the olive is pressed or crushed. It will leak.

 

[p3eps]

If the brake line and barb are not held securely in place during installation, the final seat will not be correct when the olive is pressed or crushed. It will leak.

I’ve got a bag of barbs / olives, and I do have enough slack to lose about 10mm.

I’m going to borrow a hose cutter from work and re-do the connection tomorrow and see if that works any better. I’ve removed both bleed screws and checked them, but they both have ‘new’ looking seals and there is no debris or anything in the threads. Can’t see it being them leaking.

If it’s still leaking after re-doing the hose, then I see you can get just a brake assembly (no lever) for about £60, so that would be the next step if the shop don’t play ball with a warranty claim.

 

[cozzy]

I could hold pressure on the lever and it would gradually creep back to the bar.
It wasn't leaking but a bit more tightening of the banjo sorted it.
Ultimately I cut the crappy plastic levers off and fitted Shimano xt ones instead. Perfection.

 

[Airyagarn]

I could hold pressure on the lever and it would gradually creep back to the bar.
It wasn't leaking but a bit more tightening of the banjo sorted it.
Ultimately I cut the crappy plastic levers off and fitted Shimano xt ones instead. Perfection.

I did the same. Replacement Magura levers were ridiculously expensive, Shimano XT less than half the cost. Completely different feel with bugger all modulation, but I prefer that to how the Maguras felt. I also had endless arguments over a leaking banjo crimp on a brand new hose I fitted, Magura would not warranty without me sending the whole brake set to them for testing - complete bullshit. Had to buy a second hose because I didn’t have time to waste on that process. In summary of Magura: fantastic calipers, average levers that failed within 2 years, worst customer service for what is supposed to be a premium product.

 

[p3eps]

Looks like I’ve solved one issue, and now have a different one.

Just back from 16 miles, 2100 ft… which required some heavy braking.

The brake felt pretty solid before starting, and was fine for little pulls. When pulling it on for more than 5 seconds, the lever would slowly pull back to the bar… but if I let it go and pulled it again 5 seconds later - it would be firm for a few seconds then gradually pull right back to the bar again.

Pretty useless for a long technical descent near the end of my ride.

What now? Would this be air in the system that I can bleed again?

The shop I bought the brake from have offered to send it back to Magura… but I can’t make up my mind if there’s actually anything wrong with it other than ‘operator error’!!

 

[p3eps]

I could hold pressure on the lever and it would gradually creep back to the bar.
It wasn't leaking but a bit more tightening of the banjo sorted it.
Ultimately I cut the crappy plastic levers off and fitted Shimano xt ones instead. Perfection.

Sounds exactly like what I experienced today. I just wonder if I have air in the system, and if a good bleed would fix it?
I don’t think my banjo will go any tighter!

 

[cozzy]

Sounds exactly like what I experienced today. I just wonder if I have air in the system, and if a good bleed would fix it?
I don’t think my banjo will go any tighter!

That's what I thought till I cranked it another few degrees tighter.

 

[p3eps]

That's what I thought till I cranked it another few degrees tighter.

It genuinely won’t… I tried last night!

I’m so fed up of it that I ordered a complete new MT7 today… and will send this one back for warranty once I get it.
It’s only light nights and decent weather for a couple of months… and I don’t want to spend most of that having to bottle my downhill runs because I only have 1 working brake!!

 

[CarolinaCrawler]

It genuinely won’t… I tried last night!

I’m so fed up of it that I ordered a complete new MT7 today… and will send this one back for warranty once I get it.
It’s only light nights and decent weather for a couple of months… and I don’t want to spend most of that having to bottle my downhill runs because I only have 1 working brake!!

My wife's mt5's were doing the same thing. They were fine for 2-300 miles then started needing to be "pumped" up periodically. It got to where she was not comfortable riding. I bled the brakes 3 times and threw every trick in the book at them. I even bled them from both ebt ports. Nothing fixed it. I finely swapped on a spare lever (they are Magura levers, always have to have a spare when they brake so easily in a crash) and it bled perfectly. Had it fixed in 20 minutes. Have no idea what was wrong with the other lever, but swapping them fixed the problem after 3 evenings of bleeding.

 

[p3eps]

My wife's mt5's were doing the same thing. They were fine for 2-300 miles then started needing to be "pumped" up periodically. It got to where she was not comfortable riding. I bled the brakes 3 times and threw every trick in the book at them. I even bled them from both ebt ports. Nothing fixed it. I finely swapped on a spare lever (they are Magura levers, always have to have a spare when they brake so easily in a crash) and it bled perfectly. Had it fixed in 20 minutes. Have no idea what was wrong with the other lever, but swapping them fixed the problem after 3 evenings of bleeding.

I ended up buying a whole new brake assembly (lever, hose, caliper, pads).
Chopped the hose (probably a bit longer than it should be) as it’s a front brake, and bled it. Bedded the pads in as per Magura’s instructions, and it works perfectly.

As the one with the issue was only a month old, I’m tempted to return it for warranty when I get home from my holidays.
Must be some sort of airlock issue… but I can’t figure it out!