Come on, 5 more minutes..
Brake cable keeps popping out! (ending in spectacular crashes)
OK.. I'm a slow learner. This is the 3rd time my rear brake cable has popped out while on some single track, ending with me over the bars. Epic fail, wish it was recorded, but that's another thread.
Cable end that goes in the lever, just pops out. Does not break. Nothing that I can see is loose. Lever works fine, no binding. No cable issues that I can see. Bolts are all tight everywhere.
I realize the Shimano Altus C-10 is pretty much low end stuff. (on a late 90's Specialized HardRock)
I've pulled absolutely everything relating to the rear barkes apart, cleaned, greased and re-assembled. All seems normal. Then in a week or two, during a ride, the cable pops out, and rear brakes are gone again.
Sounds like you are hooking the ball of the cable on the outside of the holder as it belong in the middle or center of the holder for the ball end of the cable. If this is not it then look at the other lever to compare s the rear lever maybe bent or deformed in such a way that the cable is pulling through the holder, see front brake lever mount to compare and see what is different and bend it back to match this lever holder. Possible may need to replace it to fix it.