Anyone know anything about disc brakes?

Posted on
of 311
  • I would still try the tape wrap first - if it works it'll make bleeding it next time a lot easier but if it doesn't work you can always go in all (glue) guns blazing.

    True. I'm being very imptient after the 3T cracking. I get a new frame and now this. I'm going straight down the middle with some gorilla tape and PTFE. Might as well always ride on the hoods pressing down for good measure too 🤣

    Local bike shop ETA for new shifter is...... 22/04/22. Yeah. Good one Madison/Shimano.

  • 22/04/22

    One of the early things back in stock, lucky you.

  • Could you drill out what is left of the hole then bond in a new thread?

    I know I know, it will be tiny..but maybe there's an insert that could be sourced.

  • This would be sensible. a hole drilled and appropriate metal thread bonded in.

    However I bought a glue gun and stuck it in instead. Oh, and made a nice cover over the top. Same principle though right? Bonded etc.
    It's flexible enough that I can chew it off and then pop out the screw with a chisel or something levering underneath when I need to blead the brakes again for my Black RX4s that are on back order.

    Would add; I tried PTFE (25p option) first and then some tape but it was oozing ever so slightly. I'm heavy and go fast downhill soooooo.... went in all (glue) guns blazing.

    Took me back 20 years to DT at school too 😁😁

  • Most of the sealing for the bleed cap comes from the rubber o-rings rather than the thread.

    Did you inspect this? Potentially this was damaged too and PTFE plus new o-ring/ bleed cap would do the job?

  • Gonna run a tap in to the glue then screw the cap back in? Will probs be fine

  • @motoko the thread on the bore has gone, so even with the intact o ring and ptfe there was nothing to grab.

    I took a look at it further and it appears by the cap is purely a reservoir. There is a small hole that created the closed system the moment you pull the lever. I suspect that just there is absolutely minimal pressure on this top cap thus the glue ive bunged in will hold and the extra safety net - Glue may be my unsticking on a hill, ha! - of a lovely gluey cap over the top to increase the adhesive surface.

    Either way i've closed the 20+ lever / groupset chrome tabs i had opened and consider this resolved. Dura Ace 12spd where art thou? :)

    20 degrees tomorrow... better wash the summer kit!!

  • I digress.

    The brake is the thin line between stopping and breaking (pun intended) you.

    Swallow the bitter pill and get a replacement, nothing brakes is a no no.

    Hot glue gun - was the bonding surface cleaned thoroughly of brake fluid? One of many other questions...

    Tl;dr: replace the unit OP and give yourself the piece of mind.

  • Yep there is no pressure in the reservoir in normal conditions including braking - unless you’ve managed to overfill somehow.

  • Tl;dr: replace the unit OP and give yourself the piece of mind

    I'd love to. I've been searching all day for a R8070 replacement to no avail.
    This is a temp measure believe me.

    Yes, surfaces cleaned with brake cleaner etc. It sounds like there is next to no pressure in these systems and my Chernobyl style Glue cacoon will suffice. For now.

  • Update: urgh. You can't get a good bleed without the funnel and then sealing it is losing that little bit of oil that makes it all good. I also flipped the bike to align the calipers and now I've lost all bite. FFS.

    I really need a r8070 Left leaver. Or a pair. Or some R9170s.
    Anybody got some gathering dust?

  • Gonna run a tap in to the glue then screw the cap back in? Will probs be fine

    Was just thinking this. It should work if done right

  • Seems to be a regular occurrence, given post quality.

    Which lube do you use? Might be time to upgrade.

  • Finally got my bike up and running again after replacing the broken LH lever. Tiagra hydros are light years better than the juin tech R1s they replaced. Can recommend.

  • I also flipped the bike to align the calipers and now I've lost all bite. FFS.

    You’ve likely sorted it but you can get most (if not all) of the power back by picking the bike up an inch and dropping it. Pump the brakes after a few drops and it should be good to ride.

  • Ha.
    I’ve gone all Dammit and just bought a new lever. 😬

  • You don't have to drop it. Just pump. Recent Shimano stuff is single valved pressure system. We used to have to this to about 50 bikes every Monday after storing bikes in a rental place.

    You can leave a hose disconnected for a whole day and still have pressure when you screw it back in.

  • eBay US. Stung on import charges. but came in on par with what I'd pay for a new one here if they were in stock anywhere(this is boxed mind). I'll just be happy to ride my SL7 for the first time... it's leaving the US today so fingers crossed it'll be here in the next week.

  • While waiting for Hope to ship my new calipers I've temporarily mounted cheap Deore calipers to my R685 lever. Seems to work fine...

    1 Attachment

    • PXL_20210407_132949440.jpg
  • You sound surprised... ;)

  • I guess I was / am

  • new magura mt trail sport brakes installed by my LBS, hoses shortened.
    new pads, new discs, complete new build bike.
    I collected it today and bedded in both as detailed by magura.

    rear is grand, nice and powerful, skidz for days
    front is woeful, doesn't lock up fully, can't endo even if I yank it hard, makes a squeaky sound under full braking pressure, makes a repetitive ticking noise under medium to hard pressure

    what's gone wrong?
    should I take it to lbs and demand a fix at no extra cost?

  • Set fire to the glazed pads. Plus sand the disks to roughen them up again .

  • why would the pads be glazed if the whole system is brand new?

  • Post a reply
    • Bold
    • Italics
    • Link
    • Image
    • List
    • Quote
    • code
    • Preview

Anyone know anything about disc brakes?

Posted by Avatar for Sanddancer @Sanddancer