Tired of Brake Problems

i would try another dealer, or a qualified hybrid brake repair shoppe. do they not stand behind their work? they are not getting at the heart of the matter. prius brakes are some of the best in the world and are of very little trouble over hundreds of thousands of miles.

how many miles on your car, and front or rear brake problems?

 

quick fix for glazed brakes: buy some valve grinding compound and an acid brush. put a thin coating of the valve grinding compound on the rotors and take it for a slow drive, braking easy. the valve grinding compound will sand the glaze off the pads and rotors. done it to hundreds of cars and it usually works.

 

Has anyone ever adjusted the rear (drum) brakes? The self-adjusters only work when applied in reverse, and if you're like many, maybe you seldom brake hard in reverse (my wife doesn't). I adjust hers manually every other tire rotation or so. (Does the parking brake work OK?) If the rears are way out of adjustment, the front may be working too hard.

I think it's unusual for a Prius, with regen braking, to be wearing down brakes in 90K miles.

 

btw, to activate the brakes when driving over 6 mph, put it in neutral.

 

Excessive brake dust sounds more like aftermarket pads than OE pads. OE pads have chamfered edges already.

Avi

 

OP is from the UK and the European 2G Prius have disc brakes at all four wheels.

I agree the OP should inquire into the source of the brake parts used by his servicing dealer and require that the correct Toyota parts be installed if they had not been previously.

I am wondering what "uneven braking" means. Does that mean that the brakes work more efficiently on one side of the car vs. the other? Or does that mean the brake pads are wearing unevenly? If the latter, perhaps lack of caliper slide pin lubrication might contribute to uneven pad wear.

 

What color are the brake pads? Green, brown, blue, black? Underneath the brake dust, of course.

Avi

 

Check your calipers. Generally Prius owners do not perform preventative maintenance to their brake systems, either because Toyota does not mention it or because with the regen there is less wear. Gen III's use DOT 3 brake fluid and I think Gen II's as well. Dot 3 & 4 Brake fluid should be change/flushed every 30K miles or so. The result of not doing so means water in the system which means corrosion. When this happens in the caliper bore it can cause sticking pistons and a variety of other problems.

 

This actually worked for about two days. Rained, so unsure if related or not. Thinking I'll disassemble and inspect to see what pads were used. From reviewing at the salvage yard, the new ADVICS calipers are black and the lettering is smaller and more to the side. Both yard 2007's calipers were aluminum and the ADVICS lettering was larger and in more towards the center.

Was reported with documentation that the brakes were replaced this last winter and appears as such, though I need to take the wheels off to see if the green pads are present as well as the Toyota shims, since I see the backup pads I got from the nicest looking yard car are aftermarket and the shims don't have those three slits cutout in the one. Will see what's installed on mine next when I get around to.

Performs great, just sounds gnarly for some reason again starting today. Sounded perfect for a few days though. Using the 240 grit Clover lapping compound, so can confirm that does do the trick. Maybe the 120 grit next?

I'll measure everything to Toyota spec when I have the tire off as well. Guessing, like the gen 3, there is a run out spec as well so will bring out the dial indicator with magnetic base too along with some washers.

 

Somehow this thread goes back to 2015 and no one has posted the common knowledge yet.

Prius brake rotors tend to develop surface rust, especially if the car sits parked in humid or damp weather for a day or more. The brakes don't scrub it off the rotors as quickly as they would in another car, because the Prius doesn't use the brakes as much as another car.

Pretty much any time you get in a Prius that's been sitting long enough in damp weather, and you drive away, you will notice awful brake sounds, and grabby/hard-to-modulate behavior. It's just what happens, and there's a super easy fix.

Just shift into Neutral before your next two or three stops, and brake to a stop as you normally would. Shifting into Neutral forces the real brakes to be used, and a few stops like that rubs the rust off.

You'll see some posts where people make a way bigger production of it, like speed up to nn MPH, shift to Neutral, brake extra hard, and so on. Fiddlesticks. I live on a neighborhood street with a few stop signs on the way out of the neighborhood, and if I just shift to Neutral before stopping normally at those, that's all it takes. If I have passengers and they can even tell I'm doing it without seeing my hand on the shifter, I'm not doing it right.

It comes to be second nature. I'll just hear/feel that brake roughness and do a couple Neutral stops, sometimes almost without noticing I'm doing it myself.

It's just a Prius thing, and it's been true of every generation all the way back.

And it's weird how many shops pretend not to know about it, even Toyota dealers, which is absurd. In this thread, a dealer repeatedly fleeced an owner for $900 brake jobs every time it happened, instead of explaining how to shift into neutral and stop.

Rusting Brakes are killing me financially - any ideas? | PriusChat

Drum brakes can have a couple common adjustment schemes, "reverse-travel adjusters" or "parking-brake adjusters". The drum brakes used in Prius models are not the reverse-travel kind. They rely on applying the parking brake often enough.

Applying the parking brake will 'cock' an adjust lever over the adjuster starwheel (if the shoe clearance is more than 0.03 mm at the time), and then the lever will turn the starwheel the next time the regular brake is used after releasing the parking brake. That one-two action will reduce the clearance 0.03 mm at a time until it is in spec.

 

Interesting and makes sense. Will try next when out.

What are you thoughts regarding the glazing of the rotors? My thought was all day on the road stop and go.

My 2006 had and looks like the glazing is back (though did rain last night and I've not checked this morning), where the rotors have a super smooth polished mirror almost like finish and barely any grooves like those that are present with a rougher surface in my 2013 rotors which definitely do have the Toyota parts?

I wasn't confident if the pads were moving back away from the rotor and the wire spring to separate away from the rotor like on the gen 3's are present. Was thinking might need to remove the clips as well and clean the caliper mount area where the clips go as well as clean the clips and re-assemble using brake grease and not what appeared to be copper anti-seize. Same goes with grease on the anti-squeal shims where I'll try to find a yard set to at least use those if the solid aftermarket.

I'm even having thoughts of belt sanding down the pads to remove some and deglaze the surface if is. Using a long backing board with a level to assure the surface is uniform level flat with the backing plate.

I haven't looked at the pads to confirm the glazing, though I assume they are as well.

 

I've been known to take some 100 or 150 grit wetordry paper under a brake pad and rub on the rotor for a while, wet, and then turn the paper sandy side up and rest it on the rotor and rub the pad for a bit. I haven't gone more elaborate than that.

 

Imo, an overhaul of the rotors and brake pads had to be done, but then it also needs proper bed in by the technician. The bed in process requires speeding up to 60mph and slowing to 15mph very quickly and for a few times. Maybe the tech didn't do this. I don't know many DIYers who even do this.

 

Under normal conditions, the pads and rotors wear together - the surfaces will look "smooth and shiny" but work just fine when the brakes are applied. If the rotor becomes groovy, that's somewhat abnormal wear (but not by itself reason to replace anything).

Really, you're overthinking this. As long as the pads and slider pins move freely in the caliper brackets, leave your brakes alone and just drive the car. Scrub the surface rust off as needed with neutral stops, and don't worry about it.

Truly "glazed" brakes happen when you severely overheat the friction material, which chemically alters the resins in the pad near the contact face. This causes reduced coefficient of friction and very poor stopping function (need more pedal pressure). At this point the pads are permanently ruined.

Glazing often occurs to new brakes that are not properly "bedded" or "broken in". You need to perform 10-15 gentle stops from slow speeds (in neutral on a prius) with cool down time here and there. This allows the pads to conform to the rotor surfaces on a "microscopic" level - some friction material is actually embedded into the rotor as things wear together.

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I don't know anybody who even does it, and yet the cars stop when the brakes are used.

 

Might be different in the Prius community, because of regenerative braking. Less use of friction braking overall, with much of it occuring at low speeds (like it does its own "break-in").

Maybe newer friction formulations are more tolerant of aggressive initial use.

All I know is most friction manufacturers have specific break-in procedures for new parts. So that's what I've done over the years. Seems to result in very few come backs for noise or functional complaints.

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No clue other than the car came with a heads up that the ABS Actuator-Accumulator might be starting to go bad though didn't sound like yet. Plus, of course, the associated ABS and VSC dash lights. After running the scan tool, found that the passenger rear hydraulic pressure was too high (I think I'm recalling that correctly) and after removing the drum I found ultimately that the adjustment lever was not installed correctly. Long story short, I correctly re-installed the adjustment lever inside the strut fork as was not found that way and therefore was not originally engaging the strut star nut causing I assume the strut to be in a really stuck tightened down position. Correctly installing, with a newer looking and performing yard strut part since I vice gripped gnarled the as-found part up trying to unscrew, resolved the ABS VSC dash light situation.

From researching a little more, the calipers appears to be re-manufactured ADVICS and I'm guessing same goes with the caliper mount bracket.

Now that I think about, I was wondering if there is a brake related calibration procedure that would optimize the lifecycle of the ABS Actuator-Accumulator part and possibly correct? Seems I read that is a thing with these hybrids specifically?