My rear brake was spongy and progressively becoming worse. Pads? Rotor?

Today on the ride home it went from wouldn't stop well, to wouldn't stop at all!! Did I snap a line? what the heck happened. I get home and this is what I see.



Yes that's a screw missing, and prior to this photo, the one on top was tightened, as it too, was about to fall off.

Why is it a big deal? You can ride with just one screw, right? Wrong. This is what happens when only the top screw is tightened



The pedal actuation moves the master cylinder instead of pushing in the plunger to compress the brake fluid. I.E NO STOPPING POWER

Kind of an odd thing to happen, because the 351 vibrates more? I've never touched those screws since owning the bike. I suggest everyone go out and check them out, could be a scary disaster down the road. (yes I realized the rear brake wasn't working when it started raining and I was slowing down to a stop sign...)

 

A loosening rear brake master cylinder isn't something common, but it does have bolts, so it's not impossible. A new bolt, a little Loctite, and you're good. Better that than what neonarc is trying to diagnose on his brake system.

 

Definitely better than my issue. I wish I had it that easy jaja

 

Quite fortunate indeed, after as much headache as he's gone through I'd just replace the master cylinder and the line

 

I'm one step away from doing that jaja. I'm scared I'll change the MC and the problem will still be there, then I'll have to get a new caliper jajaja. Oh well, bright side, it's a good excuse to upgrade.

 

Upgrading the line to braided stainless is worth doing even if the stock line isn't suspect.