Anyone know anything about disc brakes?

Unfortunately yes. Not the first, or the last time I’ve seen that. It’ll eventually either leak or just jizz fluid during hard braking.

If it’s brake related, don’t take chances.

Yup... New lever.

Plastic weld it? :)

Looks pretty fucked to me. I thought one of the ideas of those flanged nuts was to prevent over tightening because you pretty much just tighten it until it's flush assuming your torque wrench and crow foot spanner bit isn't too hand.

Set it on fire?

I guess I knew that. Was hoping the plastic was just a sleeve or something. Ok. New lever it is.

I’ve seen situations where people just went ham at the bolt when the olive wasn’t sitting flush, proceeded to tighten all until casing cracks.

I can imagine I'll see that at some point.

To be fair, it’s the same bullshit on the new stuff.
Those bleed port bolts are the work of a psychopath.

people just went ham at the bolt

Ahem

I’m totally gonna save this by saying that bolt doesn’t look flush, which it should be, so I’m going with bad batch shifter and bad luck!

Definitely not forcing a crossed thread.

Those bleed port bolts are the work of a psychopath.

I buy 4 or 5 at a time. I've stripped about 8 of them over the last couple of years.

that bolt doesn’t look flush, which it should be

Now that you mention it, could that little grub screw be the culprit? Wtf is it? The crack is right where it sits. Should I have backed this off before tightening, is it to prevent the bolt coming loose or something?

Ordered a new lever, found one in stock which is lucky these days with shimano stuff.

Nope. Don’t have to ever touch it.

There was no mention of it in Shimano docs, so called up shimano tech after seeing same thing happen a couple of times. Guy said it was an assembly grub screw to stop the sleeve from rotating further when you tighten the flanged bolt.

Whether that’s true, I have no idea. At this point, you might as well disassemble to see what it really does and educate us all.

@atz 0.5/0.7nm. Who’s gonna buy a torque wrench just for that??

Who’s gonna buy a torque wrench just for that?

Meanwhile...

He’s better off with a magura tech in a support car

https://www.reddit.com/r/bikewrench/comments/i2thq1/shimano_str7020_what_caused_this_crack/?utm_source=amp&utm_medium=&utm_content=comments_view_all

I’m not alone.

I'm pretty sure I've read that the 105 bleed port bolt is aluminium rather than the plastic version of ultegra/dura ace so less likely to round out. Someone on here can probably confirm.

But yeah, they're shit. I use a hex plus tool which seems to help.

No you're not, I've seen it a few times. I cracked a Dura Ace Di2 myself for reasons unknown.

This is making me even sweatier of palm about doing my own work.

Crow foot adaptor and go slowly is the only answer I suppose.

Presumably like a compression fitting on copper pipe it doesn’t need to be particularly tight?

Make sure the olive is in the right place and don't tighten it too hard. It takes some pressure to crunch the olive but don't keep tightening mindlessly if something doesn't feel right.
I've never broken another after that traumatic experience.

This is making me even sweatier of palm about doing my own work.

I still get a mild pang whenever I need to bleed one. A good, fresh, sharp Allen key will pay you back after two uses.

He’s better off with a magura tech in a support car

Pffft I can't be everywhere, all the time man ;)