How Long Have Your Brakes Lasted?
 

Hey High Mileage Guys

How long have your brake shoes lasted? I understand the rear brakes can go first. We have 75K on our TCH and all is going well but I was curious about the brake show life. Thanks a Bunch for your input!

Re: How Long Have Your Brakes Lasted?
 

At 123,000 miles mine still look really good. Not like new but pretty close. Also, the rotors are just now starting to get a little bit of a lip. Just barely...

I have read that some people have had problems with the rears. Not the case on mine so far.

The only real problem we have had is the water pump @ 114,000 miles and I have a Pinging (detonation) problem that I have yet to figure out.

Re: How Long Have Your Brakes Lasted?
 

Did rear pads at about 100,000 miles,didn't REALLY need them but about ready. Now at about 117,000 and front are still at about 75%.

Re: How Long Have Your Brakes Lasted?
 

does not have brake shoes, has brake pads.

I had to replace mine at around 50 000, gone. Seen several posts complaining that they wore out unusually fast.

Re: How Long Have Your Brakes Lasted?
 

I mean - I had to do ALL FOUR wheels.

Re: How Long Have Your Brakes Lasted?
 

I had a dragging rear pad at 40k. Replaced the rears. Front look good at 50k. Pads are very simple.to swap..

Re: How Long Have Your Brakes Lasted?
 

Over 100,000 on mine right now and they look like they will make it at least to the 150,000 to 175,000 mark.

Re: How Long Have Your Brakes Lasted?
 

Rears started wearing in very uneven way, all of the sudden on one side went to the metal, so had to change them at about 75k. I think calipers froze at some point. Fronts are original, still good at 115k.
For the person changing 4 pads at 50k, there is something wrong there. I drive very aggressively, mostly in heavy stop and go traffic and at 50K pads looked like new on mine.

Re: How Long Have Your Brakes Lasted?
 

Also had a rear pad start dragging on the rotor at about 35K miles which needed service. At 65K miles now with no other work done...

Re: How Long Have Your Brakes Lasted?
 

At 75K now. All four look like new.

It probably depends on how often you actually use the mechanical brakes. Gentle 'braking' uses the electric motor. The mechanical brakes are used only when you have to stomp on the pedal, or when you are almost stopped.

I do press them rather firmly, at least once or twice a week, when I back out of the driveway. Mechanical brakes do their "adjustment" when you operate them while traveling in reverse. They do need the periodic adjustment.

Re: How Long Have Your Brakes Lasted?
 

Steve, drum brakes with self adjusters are adjusted when backing up in reverse. The Camry uses 4 wheel disk brakes which do not need "adjustment". The braking on the Camry is biased to using the generator for braking when the car is going faster than 10 mph and you are not in a "panic" stop. Under 10 mph, the car with use the hydraulic brake.

Re: How Long Have Your Brakes Lasted?
 

Can someone either give me a link or an explanation of how the braking works on the Camry? I've been reading up on the mechanics of this car, but I don't understand the braking system.

I have two years of auto tech, but that was back in the days when four-barrel carburetors dominated the road. :)

Re: How Long Have Your Brakes Lasted?
 

TCH breaks are pretty much standard 4 wheel ABS disc breaks with 2 modifications:
1) At above 10 MPH and moderate breaking, it uses electric motor as generator of electricity, that causes the car to slow down and recharge the batteries at the same time, similar to breaking with engine in L1, or downshifting manual transmission to lower gear and drag the wheels by engine to lower speed, except it's done automatically by computer in TCh.
At lower speeds, or harder press on the break pedal break pads are activated and take over.
2) Since in hybrid car the engine could be shutdown while moving, instead of engine vacuum, TCH uses 12 volt battery electricity, boosts it to I think 50 volts and uses that to power assist the breaks. I don't remember and I'm too lazy to check exactly how it's done. I think it creates some hydraulic pressure and holds it in reservoir so you have one or 2 "pumps" after engine shutdown before boost is gone, just like in regular car using vacuum.
Service manual has all the info and way to check and repair it as well, so I would recommend to get that.

Re: How Long Have Your Brakes Lasted?
 

Vaguely remembering something here...

Since the regenerative braking is only on the front wheels, the rear brakes are applied to keep the car from losing control. That is why the rear brakes wear out ahead of the fronts for a lot of people.


For anyone who knows for sure, please correct.

Re: How Long Have Your Brakes Lasted?
 

Here is a link to consider. It is complicated.

There is another link here, with lots of pictures and schematics, but not a lot of explaination.

Re: How Long Have Your Brakes Lasted?
 

105,000 on my 07 Camry. Mechanic says maybe by fall I'll need rear brakes. Front still at 75%.

John

Re: How Long Have Your Brakes Lasted?
 

I'm at 114,000 miles and still have all 4 original brake pads with plenty of life left on them.

Re: How Long Have Your Brakes Lasted?
 

Pulled all four wheels this weekend to re-torque them (they didn't when they put on the new tires..) and checked the brakes while I was there. At 105,000 miles, the front pads will still be there at 300,000 miles as they have roughly 1mm of wear. The rears might need to be replaced around the 200,000 mark as they do have additional wear (3-4 mm). All in all, you can't say bad things about brake life on these Camry's.

Re: How Long Have Your Brakes Lasted?
 

Thanks for the feedback Guys! My wife is the main driver. I am worried they are not going to last. Keep the posts coming!

Re: How Long Have Your Brakes Lasted?
 

Thank you for ALL your notes. We did poorly! I have added a poll as well. We made it to 71K >:

Re: How Long Have Your Brakes Lasted?
 

I wonder if the life is correlated with temps? As in the ECU uses the rear brakes more heavily in cold climates, presumably to ensure you won't over-do front braking forces. The folks reporting the high miles on their brakes do seem to have been clustered in warmish climates....

Re: How Long Have Your Brakes Lasted?
 

I don't think so. If you ride a motorcycle with separate front and back brakes, you quickly learn that it takes little force to lock up the rear brake compared to the front. Which is a good thing, as I spent the night in a hospital after I managed to lock the front one. The point is that you can't do much stopping with the back compared to the front, and I suspect that is why rear brakes most often last twice as long as the front.

Excessive wear of the rear brakes might be caused by careless use of the parking brake, leaving it on, or partly on, or having it badly adjusted. That will take a toll on the rear brake pads and disks.

Re: How Long Have Your Brakes Lasted?
 

Don't believe that's possible - my 2008 Camry (and all G6 Camry, for that matter) uses a drum-in-hat parking brake -the disc pads aren't involved at all. AFAIK Toyota doesn't use the design where service disc brakes are used in the parking ("emergency" brake) design. The hat has ID of 170mm and more-or-less conventional drum brake setup, with the brake shoes activated by cable, and expanding against the drum contained in the rotor 'hat'. The rear calipers are hydraulic only, and not involved in an parking brake action.

Now, the older rear drums are were indeed different - but the TCH has 4 wheel disc, and the disc brake pads are not involved in parking brake action.

As to my reference - on the TCH, the computer does brake proportioning and manages the caliper apply pressures independently of direct driver input. My supposition was that the rears would be used more in cold temps and and related risk of front-wheel lockup. On the TCH, the rears are used to 'balance' the car while the regeneration mode of MG2 takes place. Limited by battery charge rate, up to .3G of braking torque is provided by MG2 on brake apply. The ECU also manages front caliper pressures as the car slows, or if the demanded stopping rate is more than the MG2 can provide. Really a cool piece of technology - and quite a piece of software that manages the whole shebang.

And, FWIW, 70K life on rear brake pads is pretty close to 'average' on a ICE-only car in a suburban setting. Since the bulk of light brake torque on the TCH is supplied by MG2 in regen mode, the fronts will last for darn near the life of the car, if driven conservatively. My concern about the brakes - and one I intend to remedy on my next service - is the quality of lube on the caliper pins. Since my car is pushing on 5 years, a clean-and-relube of the brake sliders is in order. In a salt-soaked environment, that frequency should be higher. When I inspected the brakes at the last service, the pads were less than 10% worn, after 45K miles of suburban commuting. The only annoyance is the occasional squeal when backing up....

Re: How Long Have Your Brakes Lasted?
 

Agree if it is a drum in disk type design for parking, you can't misuse the disk pads or wear the pads from mis adjustment.

Still I would expect less wear from the rear, just because they don't have that much traction before you lock them up. It is possible the braking system is smart enough to add front braking from regen to the actual front braking, and keep that in balance with the rear braking from the pads only. That would bias disk brake force more toward the rear. But still in a hybrid braking force needed for other than emergency stops should be pretty minimal. My biggest worry about the hybrid brakes is that they will seize up from under use. That causes problems of uneven wear; inside pad vs outside, or front to back of the pad, and early replacement.

Hybrid brakes may need a bit more cleaning and lubrication type maintenance, but with that should last the life of the car.

Re: How Long Have Your Brakes Lasted?
 

Ron,

The rear brakes are used ALL of the time when stopping the car and will more than likely last the same amount of time as normal brakes do for your driving style and route. The front brakes however are rarely used except in a hard braking situation or under 10 mph.

In my case with a 20+ mile interstate route to work and very few redlights once I am off of the interstate, my rear brakes typically lasted 150,000 in a full sized sport ute. Front brakes were replaced every 75,000 or so. With the Camry, the rears are showing some wear but should make 200,000 (due to a lot of traveling to job sites on the interstate). With me being careful, the fronts might last the lifetime of the car.

I plan on pulling mine and cleaniung/relubing where required as soon as I get a chance. I need to take a weekend and change out the water pump, thermostat, hybrid coolant and do a front end/strut/brake/bearings check.

Re: How Long Have Your Brakes Lasted?
 

Well this is really interesting. I was not aware of the front brakes were nearly all regenerative. So does this mean the maximum regeneration is from front braking and not the B mode? This would explain our lower mileage on our rear brake shoes.

Re: How Long Have Your Brakes Lasted?
 

Have a look at the link below and check out the diagram at the bottom of page 16. There has been a change in the braking system of the Toyota Hybrid System. While the early version on the Prius always used some hydralic braking, now with THS-II, you get significant braking from regeneration alone. I suspect that is due to the integration with ABS to prevent the front wheels from skidding.

THS-II

Re: How Long Have Your Brakes Lasted?
 

All regenerative braking comes from the front wheels. Only the front wheels are connected to the generators. B mode is a combination of engine braking and regenerative braking. Engine braking again is only the front wheels, as the engine is only connected to the front wheels. So B mode is all front wheels, and no brakes.

I'm not convinced all manual braking uses the rear brakes in the later Toyota Hybrid Systems, including the TCH. There is no real technical reason for it to be that way. The ABS will prevent the front wheels from locking up. See link in previous post.

Re: How Long Have Your Brakes Lasted?
 

Ron,

The rear brakes are used ALL of the time. The front brakes are either regenerative or hydraulic depending on speed and the amount of braking required. The front brakes have more of a bias than the rears but the car is braked front and rear every time you use the pedal.

Re: How Long Have Your Brakes Lasted?
 

Is their an indication of the transition from Regen to Hydrolic? For now I am just guessing.

Re: How Long Have Your Brakes Lasted?
 

Sorry, that is not what the Toyota paper I posted above says. Please provide some justification for your opinion.

Re: How Long Have Your Brakes Lasted?
 

The instrumentation may depend on the year of your TCH. In the 2012 there is an ECO display on the left side. It shows charge current. In cruise, the controls are able to virtually pin the charge to full current. I do not believe cruise has the ability to use hydraulic brakes, only regen. My conclusion based on this is that hydraulic brakes are not used (at least in the 2012), until after the ECO charge needle reaches full scale.

Re: How Long Have Your Brakes Lasted?
 

If you pay attention while slowing down you can SOMETIMES feel the transition between them. Toyota engineers have that algorithm down pat for a seamless transfer between the two. The hydraulic brakes are also electronically controlled by the computer to help with that.

Re: How Long Have Your Brakes Lasted?
 

Ron,

The Toyota paper is describing the hybrid system only on the drive wheels. For the drive wheels, yes, they are either hydraulic or regenerative. The rear brakes however MUST be used or the butt end of the car will pass you on the way to doing a 360. The brakes are biased to the front but the rear brakes are there to provide stability during braking. Call your local Toyota dealer and talk to the tech that does their hybrid work. Don't talk to the idiot sales people or a service writer, talk to the guy that works on them and ask him. Failing that, write Toyota engineering and get the answer straight from the guys that design the system. I had several long talks with them during this years capstone design competition at Georgia Tech about the cars and how they work.

Re: How Long Have Your Brakes Lasted?
 

Please provide a reference.

Re: How Long Have Your Brakes Lasted?
 

There are two reasons I remain skeptical. One is that any use of the disk brakes is a waste of energy. Toyota is not leaving any stone unturned in the search for better mileage. Always using the rear disks would reduce energy regenerated through a permanent loss due to heat in the brakes.

The second reason is that the hybrid very aggressively uses regenerative braking to control speed going downhill in cruise control mode. I would be really surprised if they were applying the rear brakes in cruise control. Assuming that is true, then the butt end of the car would be passing you every time cruise applied regenerative braking.

Re: How Long Have Your Brakes Lasted?
 

Oddly enough, this is exactly wrong. Locking up just the rear brakes (on a flat surface) will cause the car to do a 180. Locking up the front brakes will cause the car to skid straight ahead (regardless of the steering wheel position). If you don't believe me, take a toy car (a matchbox car will do fine), put it on an inclined ramp, and put tape on the top of the rear wheels to keep them from spinning. Let it go down the ramp, and regardless of how you start the roll, the car will end up sliding down locked up wheels first.

The main purpose of the rear brakes is to offload as much of the braking loads from the front wheels as possible to minimize the likelihood of either locking up.

-- Alan

Re: How Long Have Your Brakes Lasted?
 

alan,

I agree with you when talking about locking up the rear brakes but that is not what we are talking about. When you press the brake pedal, the rear brakes will be used on the car (at a lower force than the fronts) to add enough drag to keep the car tracking straight.

Ron, we are talking about two different items. You are talking about he car using regenerative and engine braking on long grades to keep the speed from increasing. That is NOT braking with the pedal. We have been talking about pressing the brake pedal and using the brakes, not using the cruise control.

Re: How Long Have Your Brakes Lasted?
 

I decided to go check the ultimate source to resolve this disagreement, my car. Today I had an errand to run a few km away from home. On the way there I took every opportunity to use regenerative braking to slow the car down. However I was careful to not pin the regen current meter or come to a full stop. When I arrived, I quickly got out and touched the front brake disks and the rear brake disks to check temperature.

I do this as a matter of routine when I do a disk brake pad change. It is a quick way to tell if the brakes are dragging. However, when I check a conventional car, I only go a block or so, and come back. A dragging brake can get firecracker hot in no time. Also just using the brakes normally in a conventional car can make them too hot to touch, without getting burned.

So what was the temperature of the disks in this hybrid today? Front was just slightly warm, but no risk at all in touching the disk - perhaps 90 deg. F. I would estimate they had seen very minimal use. Rear brakes? They were definitely not as warm, and very hard to tell if the temperature was even above ambient -- perhaps about 80 deg. F. Conclusion? The disk brakes after all this regenerative braking testing, showed virtual non use. The bias in a bit more braking on the front was probably caused by the normal front to back distribution where the fronts do much more work than the rear. The regenerative braking cannot fully stop the vehicle as the generator force goes to zero as the speed goes to zero. This means the last bit of the stop always has to be the disk brakes. Of course I had to come to one full stop to get out and check the temperature.

I repeated the exercise on the trip home, with even more regenerative braking slow downs (but not stops to avoid that necessary disk brake to get a full stop). Brake disk temperatures were the same as the first test.

So, my car is telling me there is no automatic use of the rear disks when using regenerative braking. In fact what the temperatures are telling me is that these pads are likely to last a very very long time if you maximize your use of regenerative braking, and the fronts still may wear more than the rear.

The cruise use of regenerative braking is relevant to the discussion. If regen braking without rear brake operation causes front to back handling problems (rear end passing you), then cruise could not use regen only either.

I'm sure Toyota has gone through many iterations of braking control system, and it currently is probably one of the most complex systems in the car. However, everything I am seeing says the rear brakes in this 2012 TCH are NOT always being used during regen braking when using the brake pedal.

Re: How Long Have Your Brakes Lasted?
 

Awesome test. I love empirical data to answer questions. THANK YOU!

Being an avid radio controlled airplane hobbiest (and engineer), I learned a lot about the effects of drag and center of gravity. These lessons apply very well to cars, where the CG is nicely between the wheels always, and the CD mostly comes from the nose and windshield when not braking, and almost entirely from the wheels when braking. What we are discussing here is yaw instability due to front/rear brake. There are two interesting cases: when a wheel is locked up, and when no wheel is locked up. In the first case, always hope any locked up wheel is the front, because any rear without front lock up will lead to the yaw spin/instability. The matchbox toy car test I mentioned clearly proves that. Unlike an airplane, an unlocked wheel had enormous (relative to everything we are considering) lateral grip that prevents any yaw spin (and is why airplanes have big rudders at the rear, and why a front rudder would be unstable). That means that when there is no lockup, there is hardly any yaw stability issues to consider.

Bottom line, a well tracking (not locked up or close to slipping) set of rear wheels virtually eliminates any steering/tracking/yaw stability concerns of a braking car. Rear brakes have virtually no impact to steering ability, except when the braking is done through a differential (like regen is on the front, but is not done at all on the rear of a TCH). The only usefulness of rear brakes is to offload some of the braking forces from the front brakes.

-- Alan