# 2009 Camry, unusual brake wear



## raylo32 (Nov 25, 2006)

2009 Toyota Camry, 70,000 miles.

I changed out my GF's front brakes a couple months ago because the rotors were pulsing. The pads looked to only be aout half used but I put on new pads and rotors. I checked the passenger side rear and they looked to be only 1/3 worn so I didn't bother even checking the driver side. Now a few months later she gets metal to metal braking noise in the rear. I found the passenger side as before but the driver's side rear pads were totally gone. Any ideas why that left rear went away like that? The caliper sliders looked fine and lubed, piston looked normal. Very strange... I replaced both rear rotors and popped in new pads. Hope we don't have a repeat. 

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## cjm94 (Sep 25, 2011)

Could be that caliper is sticking. It is also pretty common for the pads to stick in the pad mounts causing premature wear.


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## raylo32 (Nov 25, 2006)

How do you prevent the pads from sticking in their mounts? In all my years of doing brake jobs I've never seen anything like this.



cjm94 said:


> Could be that caliper is sticking. It is also pretty common for the pads to stick in the pad mounts causing premature wear.


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## cjm94 (Sep 25, 2011)

Clean the contact surface and apply brake grease to prevent corrosion. I use a synthetic brake grease from Napa. It isn't a cure but I've found by switching to the synthetic the fleet pickups I work on went from sticking and wearing out in 30,000 miles to 40-50,000. I'm from a high road salt area so nothing is going to last as it should without periodically cleaning and greasing.


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## ukrkoz (Dec 31, 2010)

OP, I have 07 Camry so we share same brakes. For starters, pulsing brakes, using your term, is due to pad material build up on rotors. Uneven build up causes wobble that transfers into the frame/steering. 
General suggestion - never act on assumption with cars.
If you had pin guides lubricated, brake pad mount areas lubricated AND caliper slides easily about a fourth of an inch on pin guides, the only cause for such a fast pads use is sticky caliper or, that particular line fluid blockage. 
If I were you, I'd have a helper - a smart one - to gently press on brake pedal, to expand caliper piston on that side as far out as safe. Remove piston dust boot, squirt some quality lubricant inside, between piston and walls, press piston back in, and repeat it few more times. Just to lubricate cylinder walls. Otherwise, you need to remove caliper and bench refurbish it. All it takes is to take it apart - easy job - clean any debris/rust, lubricate all moving parts, replace O-ring, and re-assemble. 
BUT. Here's a big BUT for that car for that year. ABS block. Like any other ABS block, it needs to be properly bled, after caliper removal. Fortunately, you do not have brake accumulator, like I do, and mine can be bledd ONLY with expensive scan tool. $150 dealer.
Also, for the future reference, EVERY time you replaced rotors, they MUST be bedded immediately. MUST. Or, you will have all kinds of shakes and $$ thereafter.


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## raylo32 (Nov 25, 2006)

Yes, I always bed new pads/rotors. The pulsing fronts were the original OEM. I will monitor the problem caliper and see if it is sticking or wearing abnormally.


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## ukrkoz (Dec 31, 2010)

Aaahh, the fellow bedder!! Cool.
Yeah, they do not bed brakes at the factory. Also, folks are not mindful of proper red light braking technique, and jam brakes hard after, usually, last minute deceleration. What normally results in local pad material transfer onto the rotor. And shake down the road. Looks like spider cracks on rotor.


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## paintdrying (Jul 13, 2012)

My wife had one of those rave 4's. No I think and outlander or something like that. When her brakes started giving her trouble I took it to the dealer. I read how so many people were having problems getting the brakes to work properly, I knew not to touch it. Long story short after about 8 months of squeaking the dealer took it bad on trade for a different car. 
You have to love all these wonderful advancements they keep making with cars. 


Here in town there is a rash of bad astro van calipers. If I see someone driving an astro I ask them if their calipers are hanging up. Surprising how many people are having trouble.


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## raylo32 (Nov 25, 2006)

I learned something interesting on another of my forums... that there is a rare but possible brake hose failure where the internal liner can tear creating a flap that can act like a check valve in the reverse direction that keeps the piston from fully retracting. Never heard of it myself but if you Google it there seems to be a good bit of info.


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## 47_47 (Sep 11, 2007)

If the piston easily pushed back in the bore, you do not have a collapsing brake hose.


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## SeniorSitizen (Sep 10, 2012)

raylo32 said:


> I learned something interesting on another of my forums... that there is a rare but possible brake hose failure where the internal liner can tear creating a flap that can act like a check valve in the reverse direction that keeps the piston from fully retracting. Never heard of it myself but if you Google it there seems to be a good bit of info.


I've experienced that but on a vehicle much older. I wouldn't think that problem on a 5 year old vehicle. But then again, no telling how manufacturers are trying to cheepen rubber.


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## raylo32 (Nov 25, 2006)

Good point. if there was a blockage it should have been harder to push the piston back in, plus the hose should have bulged. It seemed to go in normally but I am using a monster c-clamp so I am not sure I would be sensitve to small variations in pressure.

Speaking of pushing the pistons in... I have always just let the fluid go back to the MC but I have seen some more recent guidance that for ABS cars you should crack the bleeder and release the pressure that way instead. I have never done that nor have I ever had a problem. I wonder if some cars' ABS is more sensitive to that?



47_47 said:


> If the piston easily pushed back in the bore, you do not have a collapsing brake hose.


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## ukrkoz (Dec 31, 2010)

hey, maybe you simply had a set of bad pads on that side?


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## 1985gt (Jan 8, 2011)

raylo32 said:


> Speaking of pushing the pistons in... I have always just let the fluid go back to the MC but I have seen some more recent guidance that for ABS cars you should crack the bleeder and release the pressure that way instead. I have never done that nor have I ever had a problem. I wonder if some cars' ABS is more sensitive to that?


That can be an issue on any ABS vehicle. I don't know if it was brought up before or not but an over full master cylinder will cause the brakes to drag.


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## raylo32 (Nov 25, 2006)

No not overfull. That is brakes 101, to add or remove fluid after a brake job to the proper level. I was thinking there might be an issue with backpressuring an abs controller or accumulator. But I really don't know if that is an issue or not...



1985gt said:


> That can be an issue on any ABS vehicle. I don't know if it was brought up before or not but an over full master cylinder will cause the brakes to drag.


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## raylo32 (Nov 25, 2006)

*learned something*

As I mentioned earlier I had never heard of brakes pulsing from uneven material disposition on the rotors as Urkoz mentioned. Well, upon further inspection that does appear to be the case for my GF's front rotors that I replaced (also replaced pads, of course), thinking that they were warping. See the photo below and you can see the zones and boundaries between the sections of uneven deposits. I probably could have simply deglazed these with a sander and put them back in service, with the original pads that still had 1/3 to 1/2 of their life left. Next time I'll check this. If the deglaze doesn't work it would probably mean they are indeed warping. Probably also need to get myself a runout gage to add to the toolbox.


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## ukrkoz (Dec 31, 2010)

Never? Really?

*The "Warped" Brake Disc and Other Myths of the Braking System*

by Carroll Smith

*Myth # 1 – BRAKE JUDDER AND VIBRATION IS CAUSED BY DISCS THAT HAVE BEEN WARPED FROM EXESSIVE HEAT.*

The term "warped brake disc" has been in common use in motor racing for decades. When a driver reports a vibration under hard braking, inexperienced crews, after checking for (and not finding) cracks often attribute the vibration to "warped discs". They then measure the disc thickness in various places, find significant variation and the diagnosis is cast in stone.
When disc brakes for high performance cars arrived on the scene we began to hear of "warped brake discs" on road going cars, with the same analyses and diagnoses. Typically, the discs are resurfaced to cure the problem and, equally typically, after a relatively short time the roughness or vibration comes back. Brake roughness has caused a significant number of cars to be bought back by their manufacturers under the "lemon laws". This has been going on for decades now - and, like most things that we have cast in stone, the diagnoses are wrong.
With one qualifier, presuming that the hub and wheel flange are flat and in good condition and that the wheel bolts or hat mounting hardware is in good condition, installed correctly and tightened uniformly and in the correct order to the recommended torque specification, in more than 40 years of professional racing, including the Shelby/Ford GT 40s – one of the most intense brake development program in history - I have never seen a warped brake disc. I have seen lots of cracked discs, (FIGURE 1) discs that had turned into shallow cones at operating temperature because they were mounted rigidly to their attachment bells or top hats, (FIGURE 2) a few where the friction surface had collapsed in the area between straight radial interior vanes, (FIGURE 3) and an untold number of discs with pad material unevenly deposited on the friction surfaces - sometimes visible and more often not. (FIGURE 4)
In fact every case of "warped brake disc" that I have investigated, whether on a racing car or a street car, has turned out to be friction pad material transferred unevenly to the surface of the disc. This uneven deposition results in thickness variation (TV) or run-out due to hot spotting that occurred at elevated temperatures.
http://www.stoptech.com/technical-support/technical-white-papers/-warped-brake-disc-and-other-myths


Also tell her to stop jamming brakes hard at red lights. Just ENOUGH to hold car still.


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