Prius Prime Brakes

Were the brake pins regularly lubricated? If not, they can stick. I believe @Mendel Leisk has a procedure he finds works well.

 

And the pins aren't even the only parts of the brakes that can stick, or even especially prone to it compared to other parts, for the amount of discussion space on PriusChat they take up.

The main important thing is to follow the warranty/maintenance guide and keep up with the visual brake inspections at every scheduled service and the more thorough inspections every three years at the latest.

There is nothing about being a hybrid that will stop the brakes from wearing out if they develop a small problem that would be easy to fix but doesn't get noticed for tens of thousands of miles. The worst part is that having a hybrid makes it more embarrassing, when you think about how much longer they'd have lasted if the small problem had been caught early in a routine inspection.

I combine my brake inspections with tire rotations, when I have the wheels off anyway, so it's easy to take a better look. I like to have on hand one each of the front-caliper rebuild rubber kit (all the rubbery bits and miscellaneous pieces to rebuild two front calipers) and the rear-caliper kit (same thing, bits to rebuild two rear calipers). I've not had to use them yet, but when putting the car up and taking the wheels off, it's nice to know if I do find a serious problem I won't need a ride to go get parts.

The single most common sticking parts I run into are the support plates ... otherwise known as the "fitting kit" ... otherwise known as the springy metal clips that sit in the bracket channels to give a place where the 'ears' of the pads can slide. Those come new from Toyota with a dry, Teflon-like slippery coating, but first that wears off, and later they get rusty, and the pads won't slide. A set of the clips is cheap and fixes that right up.

Also, the bracket channels sometimes corrode and put the squeeze on those clips, which then put the squeeze on the pad ears. That's more work to deal with, filing the corrosion out of the channel so the clips fit and the pads fit in them and slide well.

As for the much-talked-about pins, pretty much all I ever do with those is push/pull on them a few times to wake the grease back up. In the time since the last inspection it can get a bit like peanut butter just because they move so little in normal use. A few pushes and pulls and they'll feel all smooth and greasy again.

I rarely take one out, unless I notice a hole or tear in the rubber boot. Then, of course, I would take the affected pin out, clean the pin and bore, regrease, and reinstall with a new boot (from the rubber kit already on hand).

The piston itself can also be a thing that gets sticky. In that case, of course, I'd end up using most of the rubber kit, and having to bleed the brakes after.

The key is not to put undue emphasis on any one part of the brake system, but to do a good general inspection and catch whatever might be starting to turn into a problem, while it's still starting.