tips on replacing front pads & rotors 2014

yes, and yes. there are many write ups here and pics. just search for threads using key words. all the best!

 

Nothing that unusual, except the safest approach would be to disconnect the 12 volt negative lead at the outset, and when you're done, before reconnecting: depress the brake pedal multiple times, build up pressure. I've used that method and there were no warning lights, issues.

Disconnect the caliper completely, secure it out of the way with a bit of string. It's a good idea to hold the caliper pins at the shoulder, with a slim 17 mm crescent wrench, while removing the caliper hold-down bolts. OTOH, Honda's are similar construction, and I've never bothered with them, just wrenched off the bolt.

Pull out with the old pad/shims, assemble the new and install. I tend to put a slight amount of anti-seize compound, Permatex or similar, on all faying surfaces, works for me.

Pull the caliper pins out, wipe clean and apply fresh grease, Sil-Glyde or similar, then reinstall burping the boots of excess air. Put a thin layer of silicon dielectric grease on the boots if you like. Push the piston back in with a largish C-clamp. Since it is plastic, you want to have full even bearing on the piston face, maybe a piece of plywood, or an old pad.

Then gently work the caliper back over the new pads, align with the mounting bolt holes, bolts in and torque. Again, to do it kosher Toyota says to restrain the caliper pin from rotating with slim 17mm wrench.

I've attached the Repair Manual section, has torque value and what not.

 

I don't get it, new brakes on a 2014, thought they should last 100K, or did someone put 100k on a '14?

 

The pads may last 100K, and I'm sceptical of that, but you really don't want ignore the brakes for that long. The schedules call for cursory and more in-depth inspections, but are VERY vague on details.

Even if pad replacement is not needed, an inspection similar to what I've outlined is worthwhile every 2~3 years.

 

Pads on my Gen 1 have 10 mm of usable wear life (they come at 11 mm, and they're done at 1 mm).

I bought my car in 2008 at 125,000 miles, and I first measured the pads that August, 9 mm at 130,200. Of course I do not know whether they were original.

The next measurement I have in my notes is from September 2012, four years later at 193,500. They were down to 7 mm, so they had worn by 2 mm, or 20%, over about 63,000 miles. At that rate, they should have had about 189,000 miles left to go.

The trouble is, what really happened was I had to replace them, and lathe the rotors, the following year, because I had let the slow pad wear make me complacent and I neglected other regular mechanical attention to the brakes, they got sticky, the typical rotor rust pattern got started and chewed up the pads, etc.

The pads had a good 50% meat left when I replaced them. Trust me, it feels extra silly to have to do a corrective brake job and throw out 50% used pads, when it's pretty clear if you had put in the regular minor preventive attention you'd probably still be on the originals.

Moral: do your preventive maintenance!

Now, one hears that in some climates, pad backings corrode badly enough that before the linings wear out, they just delaminate. It doesn't seem to be that bad here.

-Chap

 

Why you are skeptical? I am looking to replace my original front pads on 2012 PriusC. I am at 149940 miles today. The car was always serviced at Toy dealer and today is first time they recommend to replace front pads as 3mm left on them. The dealer quote me $260 and this is one of the reasons why after being toy and Lexus household for last 15 years, I recently purchased 2 cars , which are not toyota or Lexus. I got thick how greedy toy and Lexus dealers are at CT.

 

My 2012 is still on its original pads. RI requires an inspection every two years that includes brakes. Had my last one at 118,000 miles and my mechanic, who will always warn me of impending repairs needed during these inspections, didn't mention anything. Unless someone (you trust) has told you your pads are too thin, take a look before you buy parts. Prius pads last a looong time.

 

As seen in #7 above, they can last for crazy high miles, but if you're not on top of your minor inspections, you can also end up needing a brake job way prematurely, by not catching a small issue when you could have.

 

It seems that when the bolts that allow the caliber to freely move freeze up, the pads wear faster. Even with the slightest lack of mobility, this will cause the pads to remain on the rotors with more pressure than what is required. Its like driving with your foot slightly on the brake all the time. Caliber mobility is the key to the pads lasting long.

 

Maybe type of driving is a big factor, say highway miles vs stop-and-go around town?

 

Caliper mobility helps too.

Conversation gets very stuck on the slide pins around here, even though they are only some of the parts that can bind up, and in fact those on my 2010 at 145,xxx are doing fine. I make a point of wiggling them every tire rotation, that's it.

The ears of the pads slide in little spring clip arrangements that fit into the caliper bracket, and those clips (called the "fitting kit") come with a dry, Teflon-like coating on them when they are new. It eventually wears off, the exposed metal gets rusty, and that makes the pads not slip easily. Those are worth checking every so often; I've had to replace them on my rear calipers once, and after a couple years they may be ready again soon. The "fitting kit" is inexpensive.

And of course the piston, as well as the slide pins, all depend on their rubber boots for weather protection. If you see a tear or perforation in a rubber boot, best to attend to it promptly. Rust in the slide pin bores can make some brake drag, but rust in the piston bore will make BRAKE DRAG.

The last important thing, which you cannot see unless you actually disassemble the caliper, is the rubber piston seal. This part has two important jobs. True to its name, it keeps the brake fluid inside. But it is also responsible for pulling the piston back into the caliper (by about 0.3 mm) when you aren't braking. If years of heating have turned this ring of rubber hard and inelastic, you don't get the piston returning, and you have brake drag. It will feed on itself, because drag leads to heat, heat leads to more cooked rubber, cooked rubber leads to suffering.

It isn't worth taking the caliper apart unnecessarily to check that seal, but a simple noninvasive test is possible. You just want to make sure you can measure that proper piston return after a very light application of the brakes. (It has to be a very light application for checking that, because the brake system is powerful; if you're not careful, you end up measuring the stretch and recovery of the aluminum and steel, not just the movement of the piston.)



So, there are lots of reasons a brake can start dragging, and wear itself out prematurely. It can even pick up some little piece of road grot that embeds itself in a pad and starts scraping a groove in the rotor. If the grot then falls out, the groove can rust, and the rust can get a head start there, because the groove is below the surface and the rust doesn't get wiped off by the pad. A track of rust with enough of a head start will end up stout enough to grind away at the pad, instead of the pad cleaning it off.

So, the "regular brake inspection" isn't some kind of rote "check for X." It's a time to take a patient look to make sure the brakes are doing everything they should do, and none of what they shouldn't, and nipping in the bud whatever early issues you happen to find.

 

Yep, if anyone drives like the "brake light blinking" crowd I get stuck behind a lot, I agree!!

 

I'm very easy on the brakes, but mostly local street driving, at 50K miles (a bit over 80K km) I'd estimate front pad around 6mm remaining. I diassemble and relube everything tri-yearly. Last time they were around 7m and that's about 2 years back now.

 

Hey Mendel,
I see that you've attached a PDF of brake torque for a 2010 Prius. DO you by any chance have access to the torque values of a 2014 prius c? I need the torque values for the caliper slide pins and the caliper bracket bolts.

 

No sorry, don't have Prius c Repair Manual. I suspect Toyota never made a pdf, and it'd take someone getting a short term Techstream subscription, downloading and cobbling one. Which is no small task.

 

TIS (technical information service), a/k/a techinfo.toyota.com.

Techstream is the name of their software that you load on a laptop for talking to the car.