Sorry, I missed this before. The technical references I find are all in Tribology Letters and SAE papers that aren’t directly linkable. However, here and here are a couple of non-technical links that explain the process. The “melting” happens on a very fine level; excessive heat will lead to visible glazing, or vaporization (or at least excessive viscosity reduction) of the fluid layer, reducing braking force.
You have every right to call this into question; it’s totally counterintuitive to the way we ordinarily think of friction mechanisms work. But then, that’s true with friction in general. I’d be glad to elaborate on this, but it will take more digging than I’m prepared to do tonight to pull up some credible techincal references on the topic.
Here is a great site showing you the appropriate method to replacing brake pads. Note that they emphasize “DO NOT USE AN IMPACT GUN!” This is the one thing you can do that’ll screw up your rotors in short order, and many tire shops do this as a matter of routine.
[nitpick] The first step in your last cite is incorrect. You cannot use a torque wrench to determine the torque of an all ready tightened fastener. Other than that a good instructions[/nitpick]
Yeah, that’s true. Even if you could, I don’t know what the point is; the correct torque is that specified in the owner’s manual or shop manual. Here’s a guide to bolt torque, though clearly values in the OEM literature should supercede this.
If someone used an impact wrench to tighten the lug nuts on your car, you’ll know it without having to measure it. Unfortunately, you usually find it out after blowing out the sidewall on a remote road on a dark, rainy night and then discover that you can’t get the lug nuts off, especially if all you have in the boot is the cheap, stamped metal lug “wrench” provided in the car’s “tool” kit. (Effing General Motors and their shitty service “tools”.) I don’t typically pull out a torque wrench, since I know by feel and rotation how much torque needs to go on the lugs on my car; when putting the brake calipers back on, however, it’s a very good idea to use a torque wrench; my neighbor changed his pads but failed to properly torque the caliper bolt on one side, which proceeded to fall out after a few weeks. Eek!
Also, you want to be careful with any kind of lubricant and especially anti-sieze; you do not want to get this on the rotor! Grease (even from fingerprints) can be enough to impair rotor function, and the rotors should be cleaned with brake cleaner after you handle them. I’m not sure if you can even clean off anti-sieze; that stuff gets into everything and is just about impossible to remove. Most brake pads come with a little tube of lubricant for lubing the contact points between the pad and caliper.
One other thing, now that I look back through this: it looks like they’re taking the caliper completely apart. I’m not sure why you’d do this unless you are going to rebuild the piston or somesuch. Normally, I just slide the caliper off the disk and set it on a milk crate (so that it doesn’t hang by the hydraulic line), and then use a pair of c-clamps to carefully compress the pistons. Are their brakes that require caliper dissasembly in order to replace the pads?