So after rebuilding my rear brake system as per prev thread, I ran bike for 150m no bother, the rear calliper has now decided to destroy itself and go on fire aghhhhhhhhh. luckily I was able to blow it out with my helmet on. So after loosing complete faith I'm replacing the complete rear brake system, I have a disc I sourced this week, but require a calliper, the one without the raised casting to the opposite side of the banjo/bleed. Any one have a nos stashed ??? cheers Pat
I’ve got a couple but they’re from the later 996R / 998 bikes. Can’t remember if there’s any difference now. I can have a look and sent photos tomorrow evening.
They are different to the original, casting is different look shite. If that’s all I can get so be it.
No not a bloody clue, was glowing red and pads/fluid on fire. Caught it just in time or could have been much worse !
Quite frustrating as would love to reply to pacify you both but better face to face. not saying for a minute that i know the answer definitively but often feel sad that at my age I can't pass "stuff" on without being blown out of the water. If you reply then please don't quote this post.
Yep that’s what mine looked like after. I’ve put a new caliper, sourced a used master cylinder which seemed alright but now I think is suspect, changed the disc, and put new SBS sintered pads. It doesn’t get red hot and bind anymore but it don’t bloody work either. I’m going to rebuild the master cylinder.
@Chris I think I’ve tried everything else to get a working rear brake that doesn’t spontaneously combust so I welcome any suggestions. I’m sure @P1mao feels the same way. (Personally, I’m not riding on the lever dragging the rear brake, and I haven’t taken any slack out of the adjuster).
luckily many still about at various prices:- https://www.ebay.co.uk/itm/125948935195?_trkparms=amclksrc=ITM&aid=1110025&algo=HOMESPLICE.COMPOSITELISTINGS&ao=1&asc=254187&meid=e0b0498e600346fea59ceb802f7a4c0d&pid=101506&rk=2&rkt=25&sd=204449515990&itm=125948935195&pmt=0&noa=1&pg=3458402&algv=AlgoIndex5SimRanker&brand=Brembo&_trksid=p3458402.c101506.m1851 If genuine/just as removed from vehicle, the fact that this unit shows both pads wearing equally with no tapering is an unexpected bonus in terms of trusting it's condition.
You have both been unlucky overall, and a good condition second-hand replacement should be a cure to your failure. The main problem is that these units are "getting on" now, so you asking for a new one is an excellent idea, and it wasn't long ago that these were easily available from Italy (might still be the case but at a higher price). If you experience overheating on a caliper, particularly an aluminium bodied one, then there's a chance that permanent distortion has taken place within the body and/or the piston(s) so even a rebuild with new seals must be watched like a hawk just to see if this is the case because, surprise surprise, if this has occurred then the unit is more likely to partially seize when things get even slightly hot. It only takes one piston to partially seize/not retract correctly* after braking to launch a full-blown melt-down as the extra heat generated by a brake pad "not where it should be" will just build and build with a corresponding rise in the piston(s) advancing more and more due to fluid expansion as a result. The fact that this happens on the back circuit more than the front is something that has been covered on here, and i could add to it another time. ditto, please don't quote this post if replying. * in your picture above, it's almost certainly the R/H piston partially seizing that is the culprit here.
Yes I’m going new, replacing with 30 yr old second hand on a new disc is a pointless excercise. You can buy new, they are different castings, trying to find a NOS one. If not these new models will have to surfice. I will be replacing the hose and master just as due course.
I'm going to find a rebuild kit for my master. Apparently it's quite easy and quick to do, and as long as you don't have any corrosion inside, I think that it will be "as good as new" when done.
Most common cause of the rear caliper doing that is a lack of free play in the pushrod linkage. It's not allowed the pressure to release fully and gradually builds up to the point where the pads don't release fully. I see it quite a lot after "adjustments" have been made to the lever height, but the free play hasn't been put back in... For reference when looking at used or NOS parts, the calipers are still available new, with pads for £136 and the master cylinders are £64.
As I said free play 100% not the issue, all rebuilt as per other post, worked fine for 150m. Real hot evening, maybe pads started to drag or slight disc warp etc and it just snowballs. For piece of mind I’m replacing the lot and done with, the new callipers are actually different casting.
I could be wrong but I think they are both on the pushrod length problem Neil, and that's the only reason i didn't mention it. If all the conditions go the wrong way, even the factory recommended pushrod free play isn't enough and could safely be extended by 1 to 2 mm as long as rider is aware when cold.
