Brake Repair Question

The rear brakes in this car have a relatively easy life. First off, in most vehicles, the majority of braking comes from the front brakes. Since the Prius is a hybrid, it recaptures energy from braking which in turn means that the friction pads are used less often. At 96,000 miles it seems early for the rear brakes requiring replacement. It's possibly the car was driven more aggressively or in lots of city type driving. If I were you, I would have it checked out at a reputable brake shop to get their opinion.

 

agree completely^^^ maybe have them take a look at your next tire rotation. very likely the dealer just needed to make a boat payment.

 

front pads usually last between 100 and 150k. but they can measure pad thickness, so it's not a guessing game. toyota has specs for pad and rotor wear.

 

2nd rears are drums. Used vehicle, with that mileage, it wouldn't hurt to have a look-see. The fronts as well. Was there any other brake service notes in the service record?

Three years or 30,000 miles is a good interval for an in-depth brake inspection, one that goes beyond the visual look-over while the tires are being rotated. That's Toyota's recommendation for 3rd gen in the US, not sure about 2nd gen, but I'd suspect it's the same. This is regardless of pad/shoe thickness. Like going to the dentist before you have a toothache.

OTOH, I seriously think service departments are machine happy. Pad/shoe thickness check, disc/drum thickness/dia check, and disassemble/lube/reassemble of all spec'd contact points, yes. But drum and rotor machining is overdone, in my opinion.

One thing, when the rear drums, or front calipers, are off, you need to be real careful. An independent shop might get caught off-guard: if you do something like open the driver's door (at least with 3rd gen): the system will pressurize, can pop a piston right out. And if excess brake pedal is detected post-inspection, the car may throw codes.

Two good tacts:

1. Disconnect 12 volt battery before any assembly.
2. Pump brake pedal multiple times, before reconnecting 12 volt.

 

If you don't already know: there a trick for getting stuck drums off. Use a pair of M8x1.25 (by say an inch long) bolts, screw into threaded holes on drum face, to help break it loose. Just go back and forth, screwing them in bit by bit. Eventually, and sometimes kinda dramatically, they pop free.

 

Yeah, it's so easy to take the rear wheels and drums off and see for yourself, it's hardly worth having someone else do it and then having to wonder what they really saw.

My Gen 3 (discs all around), I just measured the lining thicknesses on at my last tire rotation, and they are all about exactly 50% from new-spec to end-of-life spec, at about 120,000 miles.

With a Prius, lining wear really isn't the thing that motivates brake maintenance; you still need to check somewhat regularly just to make sure the hardware isn't binding up, wear getting uneven, etc. If you just go by how slowly the linings wear, you may be letting other issues go too long.

-Chap

 

machining rotors is really a waste of time at the rates shops charge. Rotors and drums are dirt cheap nowadays when you can get a new rotor for $30 it makes more sense to just replace rotors and pads as a set. When my dad's civic wore down to metal on metal, I put on new rotors $60 and pads $60. The only thing I would pay the shop to do is a brake service which is cleaning the pistons and lubricating the sliding pin because its a pain in the nice person.

 

Nine times outa ten neither machining OR replacement is needed.

 

ROFLMAO, sounds like another CarTalk listener

 

loved the click and clack.

 

The actual facts are: a) it would be EXTREMELY rare to have enough wear at that mileage to warrant new shoes; b) IF new shoes were installed, they WILL have a different "arc" than the worn drums they will contact; c) unless the SHOES are arced to the new or turned drums, there is no sense in turning the drums at all.

There is enough flexing in the shoe tables (the metal parts the friction material is bonded to, to allow nearly 100% contact upon brake application.

In order to do drums brakes "by the book", you not only need to turn the drums (new or used), but to match the shoe arc to those newly turned drums - no one does this any more and I highly doubt I will ever meet another person who, as I, have this experience.

As for rotors, first reline you leave them, second replace them with new.

PS: DO NOT think that cheaping out is a good idea with brakes, they are one of only two safety systems on a car, the other is steering.