We generally coat the slider surfaces of calipers or caliper support with never-seize to reduce sliding friction inherent in application and self-adjustment.
Ditto the surface if the wheels to wheel hub to reduce the tendency for rust in that area. Rust is a problem in removal of the wheel, also if drum brakes are used, drum has the same problem in removal as do the wheels.
Another issue regarding rusting of the wheel or drum to the wheel hub is that loss of material can allow the wheel or drum to move out of concentricity with the wheel hub causing problems with balance and brake application. The wheels do not have to be many thousandths or an inch out of "true" to create a significant vibration.
It is to be expected that you bled the brake fluid to replace the fluid in the rear portion of the system? Old fluid has absorbed water and other contaminants from the air which increases internal corrosion and gumming up moving parts.
In order to bleed the system, the caliper bleeder nipples must be opened so this is the first thing a technicial does in servicing that area. It is much easier to free a tight bleeder nipple when the caliper is in place as opposed to loose and able to move around. If the bleeder nipple cannot reasonably be removed, it is more economic to replace the caliper and it is best to know this before remounting the caliper and pads only to have to remove it all again. The caliper lock "wedges" have a finite life so having to remove again may require replacement.
I noted that you used some "carpenter" C-clamps to push the caliper pistons back which indicated that your caliper pistons were not exceedingly tight. Otherwise those screw clamps would not have been able to effect the movement. It might be worth the mention that a tight caliper piston is an indicator that the caliper needs replacing. I don't know of anyone bothering to service calipers these days as replacements, either now or exchange, are so modestly priced.
The application of brake effort to the caliper pads should be as even as is possible, both within the caliper and on both sides of the axle. If the caliper is no able to slide easily, as noted above, the brake application will be higher to the pad on the piston side which makes for uneven application/release and excessive wear to the most movement resistant side. In addition, having resistance to release will cause the pad to drag after release, particularly after harder application.
This can cause excessive pad wear to the pad which is dragging, over heating, pulling of the vehicle to one side during braking and when brakes are released.
It is important to inspect the calipers for both proper movement in the mounts and also of the caliper pistons. We used to see many home brake jobs with big problems subsequent to the work.
Another caution is that some jurisdictions prohibit the service of brakes, steering or suspensions by other than a certified person. This came about because of public reaction to some horrendous accidents.
Good write-up, CloudDriver. I also like to block the axle hub when working on our rig at home. Seen a few which have come off stands but don't want to even think about that!
HIH
