I‘ve got an Opel Kadett 1985. Drum breaks. No matter if it‘s hot, cold or raining my right rear wheel brakes on it‘s own. Somtimes it happens often and sometimes it doesnt happen for days even weeks. I‘m driving normally and all of a sudden it just brakes/gets stuck. Sometimes it gets unstuck just as easily, but sometimes i have to either hit it with a hammer a few times or pump the brake pedal. Now, I have replaced the cylinder in the drum so that‘s not an issue. Which only leaves me with master cylinder i guess. And I do have enough oil in the brake system. What do you guys think?
Enough to fill up the core out to Chandrasekhar's mass limit of 1.4 solar masses. At that point, the core implodes. A star dies when it is forced to fuse oxygen, manganese or other lighter elements into iron. It proceeds to do that, running through its available fuel in perhaps a day, from start to finish. Once 1.4 solar masses of iron/nickel accumulate, the core can no longer refuse gravity's pull; in addition, energy-robbing reactions called photodisintegration and electron capture take whatever energy is left in the core and converts most of it to neutrinos, which immediately leave the core at very near the speed of light, and the core starts collapsing immediately, attaining a speed inward of about a quarter of light speed. The iron in the core is in the plasma state, far hotter than a simple gas can be; the iron has never been in any other state. Melting is as foreign to this as the proverbial snowball in hell, in fact, much more so.
It is not that there is iron in a star that kills it. The Sun was born with far more iron in it than the rest of the solar system had in it altogether. It is that iron is the end of the exothermic road. Fusing iron costs energy; it doesn't release it. The energy that was released by the fusion of lighter element that heated the star that held the inward pull of the stars gravity is gone. Gravity wins. The star collapses. The kinetic energy released from the infall supplies energy to fuse heavier elements. The renewed reactions sets up a rebounding shock wave that blows the star apart. Opps!
It depends on the star. The iron would certainly melt and then ionize into a plasma. In some stars it would not migrate to the core (where the nuclear reactions are), since there is no mass exchange between layers. In other stars, it would take millions of years to get to the center. Once the iron is in the core, it's not obvious that it would stop nuclear fusion immediately, since the iron core would be denser than the normal stellar core and would therefore have a higher pressure and density in the interface between the iron core and the outer parts of the star, so it might actually enhance shell burning, rather than reducing the overall rate of fusion. A big iron core would just collapse into a compact body, causing the rest of the star to supernova. In any case, it would take a substantial fraction of the mass of the star to make a difference.
A dragging drum brake is a rarity, because you have already replaced the cylinder that leaves only mechanical possibilities, the most likely of which is weak or broken return springs, also possible would be a parking brake cable ( provided you use it ) being rusted in the sleeve and not allowing the brake to release when you release the hand brake. A master cylinder malfunction would affect all brakes equally and a defective flexible line to the rear axle would affect both rear brakes. Brake systems use brake fluid, not oil, if oil has been added to the system it will destroy the seals in all of the cylinders very quickly.
