Well. it may be rare but not weird at all. My cousin 2005 Limited with 166.xxx miles the line popped when he applied the brake before turning into our neighborhood. It caused the truck veered off the road but he was able to dragged the truck home. The crack was on the rubber part just right where it compressed to the metal part. Also found one of the piston on the right caliper is seized. He fixed it up then traded it in for a new Camry.
Complete Brake Failure -- Thanks Toyota!
- Thread starter dpr422
- Start date
Well. it may be rare but not weird at all. My cousin 2005 Limited with 166.xxx miles the line popped when he applied the brake before turning into our neighborhood. It caused the truck veered off the road but he was able to dragged the truck home. The crack was on the rubber part just right where it compressed to the metal part. Also found one of the piston on the right caliper is seized. He fixed it up then traded it in for a new Camry.
BlackWorksInc
New member
You know what I just looked where you guys are located, how badly rusted/corroded were the lines? Ironically being in the Bay Area we don't see that much salt corrosion on the vehicles usually.
Bossman
Senior Member
When I turned the wheels hard right, I was able to see where the leak was in the line behind the driver's side front wheel. It seemed to be just above a fitting.
Visually, the line did not look that bad - but I do suspect that rust/corrosion played a part in the line failure (like it did when the rear line went).
I'll be telling my mechanic on Monday to replace all the front brake lines just to be safe.
4runnercolo
New member
He was right to blame Toyota, and you guys blaming the driver are seriously misinformed. Research finds total brake failure is common on 4th gen 4runners. We are selling ours and going back to a 3rd generation.
Here's my 4runner total brake failure story: 160k miles in good condition, LUCKILY I was driving with my wife, my wifes 03 4runner. Everything normal, then the vsc trac, abs, etc lights came on. Then a really high pitched buzzer went off.
THEN WE HAD NO BRAKES. It took all my leg strength just to slow down at all. Stopping was impossible. If my wife was driving she would have had zero brakes. If we were going 75 on the highway we probably would be dead.
Well, research shows there is a problem with the brake accumulator motor. I took the master cylinder out, took off this BS electric motor, took it apart, and the armature had worn completely through where the brushes ride. You lose this little electric motor, you lose your brakes. PERIOD.
Gets better, the motor costs 1400$. A motor shop couldn't rebuild it. Might as well replace the whole master cylinder assembly for $1600+, and if you bring it to a shop they will charge you $3200.
Like I said this is total crap, and illegal if I am not mistaken. (A brake system should not completely fail because of 1 bad component)
If you drive a 4th gen 4runner long enough this motor WILL FAIL and YOU WILL LOSE YOUR BRAKES. Safe? Not for my family. No way. Toyota needs to own up to this.
Here's my 4runner total brake failure story: 160k miles in good condition, LUCKILY I was driving with my wife, my wifes 03 4runner. Everything normal, then the vsc trac, abs, etc lights came on. Then a really high pitched buzzer went off.
THEN WE HAD NO BRAKES. It took all my leg strength just to slow down at all. Stopping was impossible. If my wife was driving she would have had zero brakes. If we were going 75 on the highway we probably would be dead.
Well, research shows there is a problem with the brake accumulator motor. I took the master cylinder out, took off this BS electric motor, took it apart, and the armature had worn completely through where the brushes ride. You lose this little electric motor, you lose your brakes. PERIOD.
Gets better, the motor costs 1400$. A motor shop couldn't rebuild it. Might as well replace the whole master cylinder assembly for $1600+, and if you bring it to a shop they will charge you $3200.
Like I said this is total crap, and illegal if I am not mistaken. (A brake system should not completely fail because of 1 bad component)
If you drive a 4th gen 4runner long enough this motor WILL FAIL and YOU WILL LOSE YOUR BRAKES. Safe? Not for my family. No way. Toyota needs to own up to this.
4runnercolo
New member
I thought I would update....
I ended up getting a used pressure accumulator motor/tank assembly for $350.00 from a junkyard, off a low mileage wreck. Swapped it onto my master cylinder, re-installed the whole assembly and it works.
All the buzzers and lights lit up at first, but all went out once the little electric motor pumped everything up again. The brakes needed to be bled at a shop that had the scan tool to activate the solenoids correctly. They worked ok to get it there, but were definitely squishy. I avoid the dealer at all costs so it took some calling to find an independent shop that had the scan tool.
All in all it was pretty easy, and ended up costing $500. I don't trust these
4th gen 4runners anymore, or anything else that uses this electric motor boost setup.
I will be selling this 4runner and reverting back to the much simpler, safer, more efficient, better engineered, and better built pre-01 3rd generation. These 4th gens are junk in comparison.
I ended up getting a used pressure accumulator motor/tank assembly for $350.00 from a junkyard, off a low mileage wreck. Swapped it onto my master cylinder, re-installed the whole assembly and it works.
All the buzzers and lights lit up at first, but all went out once the little electric motor pumped everything up again. The brakes needed to be bled at a shop that had the scan tool to activate the solenoids correctly. They worked ok to get it there, but were definitely squishy. I avoid the dealer at all costs so it took some calling to find an independent shop that had the scan tool.
All in all it was pretty easy, and ended up costing $500. I don't trust these
4th gen 4runners anymore, or anything else that uses this electric motor boost setup.
I will be selling this 4runner and reverting back to the much simpler, safer, more efficient, better engineered, and better built pre-01 3rd generation. These 4th gens are junk in comparison.
LTDSC
New member
i think you should give up the internet as well, its not for you.
nevada
Senior Member
you still had brakes, you just didn't have any assist. 2 different things.
also, if you ever loose a vacuum booster(it happens) you will be in EXACTLY the same situation.
4runnercolo
New member
No assist in these vehicles equates to virtually no brakes, and if my 100lb wife was driving there would be no difference at all. I am 6'2 , 200 lbs and I could barely stop. Sounds like lots of wives, teenage kids are driving these around, how does no assist feel to them?
I only wanted to post all this up, because there is not much information about the cheaper option of fixing this, mostly all I found that when someone asks everyone says, " just give the dealer $3200, that's your only option." There is a much cheaper option, you can find more about it here:
Brake Failure_uzj100 Power Brake booster repair- | IH8MUD Forum
More importantly, I'm sure many have no idea that when this motor fails, 90% of their brakes are gone. That's a huge safety issue and as these vehicles get in the higher mileage, these are all going to start failing. Electric motors wear out.
What system is more vulnerable to a failure, the old vacuum assist, or one that relies on an electric motor? You guys can put your families lives in the hands of that electric motor, that WILL fail someday, I will use what has been proven for the last 100 years, and every other vehicle I have ever owned.
More complexity does not equal better.
I only wanted to post all this up, because there is not much information about the cheaper option of fixing this, mostly all I found that when someone asks everyone says, " just give the dealer $3200, that's your only option." There is a much cheaper option, you can find more about it here:
Brake Failure_uzj100 Power Brake booster repair- | IH8MUD Forum
More importantly, I'm sure many have no idea that when this motor fails, 90% of their brakes are gone. That's a huge safety issue and as these vehicles get in the higher mileage, these are all going to start failing. Electric motors wear out.
What system is more vulnerable to a failure, the old vacuum assist, or one that relies on an electric motor? You guys can put your families lives in the hands of that electric motor, that WILL fail someday, I will use what has been proven for the last 100 years, and every other vehicle I have ever owned.
More complexity does not equal better.
truckmike26
New member
I'd love to see a brake vacuum booster from 1915. It's probably a big, shiny brass thing.
WI_4Runner
New member
Everything on a car clunks out at some point. For that matter, the next commercial airline you fly on could fall clear outta the sky as well. I'm not going to live in fear of it and will continue to drive my 4th Gen and feel safe doing so. I don't see or hear of 4Runner's rolling off the road with brake failures every day, and I'm not going to let a few posts on the World Wide Web lead me to think that these cars are death traps the way you've painted them to be.
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+1 WI_4Runner
I had a vacuum power brake booster go out on my GMC K1500 and it scared the crap out of me. But fortunately I was only going about 15 mph in a parking lot. Pushing down on the brake pedal with all your might to stop the vehicle resulted in quite the adrenaline rush, but regardless, I technically still had braking ability, just as I would in my 07' T4R.
I'm much more concerned about avoiding the teeny boppers yapping away on their cell phones going down the road or getting behind some metal scrapper with 3 refrigerators doing a balancing act on their open tailgate rather than worrying if my electronically controlled braking system will fail.
4runnercolo and his family would be best suited in a Ford Model T or some other early 1900's vehicle that has neither vacuum or electronically assisted power braking unit because both types will fail eventually.
I had a vacuum power brake booster go out on my GMC K1500 and it scared the crap out of me. But fortunately I was only going about 15 mph in a parking lot. Pushing down on the brake pedal with all your might to stop the vehicle resulted in quite the adrenaline rush, but regardless, I technically still had braking ability, just as I would in my 07' T4R.
I'm much more concerned about avoiding the teeny boppers yapping away on their cell phones going down the road or getting behind some metal scrapper with 3 refrigerators doing a balancing act on their open tailgate rather than worrying if my electronically controlled braking system will fail.
4runnercolo and his family would be best suited in a Ford Model T or some other early 1900's vehicle that has neither vacuum or electronically assisted power braking unit because both types will fail eventually.
JB.
New member
Thanks for the info and link.
I don't agree with your overall characterization of the situation, but you earned your rant.
4runnercolo
New member
I hope it helps some folks. I try to make sure my rants are also informational.
If you look through the pics in that link, my armature/commutator? looked exactly like that. I am not sure where he got a new one, or who he found to reinstall and rewind it. I felt lucky to find a good price on a clean used one, that the junkyard was willing to separate from the whole M/C assembly.
I know you guys love all your yotas, sorry to diss them, but I loved our 98 and hate this 03, for several other reasons besides this stupid brake system. I'm not sure a model T would be my ideal vehicle, but the 1996 to 2000 4runners are hard to beat.
4runnercolo
New member
You're right! I like to go out, have fun, shoot guns, hang out with women and friends, you know all that fun stuff besides making over 2000 posts on 1 internet forum.
I do appreciate finding and spreading good, useful information when necessary. Especially when it affects everyone's safety.
BlackWorksInc
New member
You do have brakes, unassisted brakes like the law stipulates; its no different than if a vacuum brake booster fails. You're trying to stop an almost 4,500lbs brick with MANUAL hydraulic brakes, that's your back-up fail-safe in the event your electronic or vacuum assisting device fails. It is no different than any other braking system out there in terms of when the assistive portion/electronic/vacuum portion fails. If you have never had to be in a vehicle this heavy when the brakes fail, then you are very lucky because manual brakes suck period and are much harder to manage the higher the mass of the vehicle. But the system worked as designed all the way into complete failure allowing you to stop the vehicle (granted with a huge amount of effort, but then again you need to understand hydraulics and some physics about the systems to fully comprehend why that is.)
As for the failure of the armatures, they're a brush motor; I would assume most if not all brush motors will exhibit this condition (starter motors and alternators of older designs being the most obvious example) at some point in their life cycle. You can't blame Toyota on a part that probably exceeded their designed life cycle (cars are not designed or built to last forever and these days they are very much a compromise between many many criteria), that's like people complaining that a TPMS Battery died a decade after they bought the vehicle (granted a TPMS battery failing is a lot less dramatic and danger prone than a brake motor failing.) It'd be the same thing with a vacuum booster having its diaphragm rupture, the casing rot/crack/rust away, and/or the hose breaking/deteriorating violently; you'd still be in the same boat.
Should the motors have been a brush-less design? Probably, it would have lasted longer but cost far more and drove the cost of the vehicle up vs. how long the current design held out. Keep in mind there are members in the 300k range with the original units on their vehicles still going strong (hell mine failed hydraulically at the master cylinder seal and not electrically) so while they may eventually all fail, there isn't exactly a predictive method to that theory beyond "It will fail eventually."
A vacuum system is just as prone to failing as the hydraulic units and even more so as the vehicle continues to age regardless of miles driven (where as the hydraulic unit might not fail just sitting there) as you're depending on a rubber diaphragm in a metal case that will start to rust/rot and is fed by engine vacuum which could be reduced/cut-off completely if engine vacuum drops too low, not to mention that is fed by the intake so fumes/chemicals could degrade those rubbers more if the vehicle has issues (a few of the main reasons why most manufacturers are switching to hydraulic systems is reliability and safety vs. older systems among many other reasons.) The 3rd gen 4Runners are not bad vehicle, but you're trying to elevate them to a pedestal that neither the 4th gen nor the 3rd Gen can ever achieve accurately (probably any vehicle made in the last 20-30 years for that matter.)
You are more than justified to feel anger, shock, horror, ect. at what happened; it was a very traumatic and very disturbing incident. But the reality is that your vehicle operated exactly as designed and stipulated by law in the event of a systems failure such as the assisted brakes portion failing. Just like any other vehicle made with electronic/hydraulic/vacuum assisted brakes, it is something that most people will never experience in their lives. But you need to understand some things about the way things work and how they are designed to see than while it was a very jarring experience due to a fairly odd failure (usually the hydraulically assisted unit sets DTCs/fails at start-up and/or the driver notices a change in performance of the braking system before it fully fails like yours did), your situation is not a common failure among the majority of Hydraulically Assisted Master Cylinder units on the 3rd Gen 4Runner (I believe in '00+ Limiteds came with the Hydraulically Assisted Units, though I am not sure what the exact years/trims are), 4th Gen 4Runner, 5th Gen 4Runner, FJ Cruiser, 2010+ Tacoma, '07+ Tundra, LC100, LC200, Prius, Prius C, Prius V, '07+ Sequoia, Camry Hybrid, Highlander Hybrid, GX470, GX460, LX470, LX70, LC Prado, ect. (it goes on a while)
Bottom line I'm just trying to point out that your emotion is justified and very well accepted; the direction that you are aiming it in the above post is somewhat mis-informed and mis-directed (and honestly not uncommon, nor unreasonable considering that most people don't know the engineering and thought that goes into these systems.)
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4runnercolo
New member
I do fully understand how hydraulics, and each system works, and that is why I think the older vacuum assist setup is much safer and more reliable.
Between myself, family and friends, I would estimate I have been exposed to hundreds of different cars/trucks. I have never, ever, heard one story of the vacuum assist failing. I do know of 2 electric assist systems that have failed. (the other was a friends Honda SUV). Anecdotal evidence, but that's how we form our opinions.
Like you said, every electric motor with brushes will wear out. I'm sure many will last the 300k these vehicles are capable of. Many won't.
Tell the housewife driving an lx470, that she just *******d into the prius in front of her at 70 miles per hour, that she still technically "had" brakes, she just lost her vacuum assist.
And I do put the 3rd gen on a pedestal, it was hands down the best vehicle I have ever owned. 255k miles with virtually no problems, still got 21 mpg, and never, ever broke down.
Between myself, family and friends, I would estimate I have been exposed to hundreds of different cars/trucks. I have never, ever, heard one story of the vacuum assist failing. I do know of 2 electric assist systems that have failed. (the other was a friends Honda SUV). Anecdotal evidence, but that's how we form our opinions.
Like you said, every electric motor with brushes will wear out. I'm sure many will last the 300k these vehicles are capable of. Many won't.
Tell the housewife driving an lx470, that she just *******d into the prius in front of her at 70 miles per hour, that she still technically "had" brakes, she just lost her vacuum assist.
And I do put the 3rd gen on a pedestal, it was hands down the best vehicle I have ever owned. 255k miles with virtually no problems, still got 21 mpg, and never, ever broke down.
Electric and vacuum systems both have a boost reservoir that will let you apply the brakes a few times without the assist working. If you pump the brakes when the car is off, you will feel the pedal get stiff as the boost is used up. If you have an electric system, the pump might come on even if the car is off.
If there's a leak, there might not be as much reserve capacity as there should be. The pump will have to come on more often (which could shorten its life), or it might need more assist from the engine if it's a vacuum system.
My last car had a very slight leak in the boost reservoir. Sometimes after it sat for a long time, like a day or more, I would start it up and there would be no power brakes. Whatever mode the engine was in when it started up sometimes wouldn't create enough vacuum until I started driving. But I would occasionally have no power brakes as I backed out of my parking space. Apparently the fix was a software change, presumably to get the engine to create more vacuum right away, but I never got around to having it done.
Some of the unintended acceleration problems come from the fact that when the throttle is all the way open (for whatever reason), the engine isn't creating much vacuum to assist the brakes. There should be enough braking power to bring the vehicle to a stop, but if you pump the brakes or if there's a leak, it won't work. Electric power brakes will work the same no matter what the engine is doing.
The parking brake can also be used to help stop the vehicle in an emergency. It's not ideal, and you should apply it slowly so you don't lock the rear wheels, but it helps.
Everyone who drives should know what to do when something goes wrong with their car. If power brakes or steering go out, they need to know it will take a lot more force to operate those systems. Sure, sometimes it might be physically impossible, but I get the sense that some people out there have no idea that if the brakes "stop working" you need to press the pedal as hard as you physically can (see the first post in this thread, for example), and then at least you have a chance of stopping. If the brakes still don't work, downshift to the lowest gear, apply the parking brake, etc. If you're going 75 on the highway, it's unlikely that you will have to come to a stop for something in front of you, so you have plenty of time to slow down, move to the shoulder, and eventually come to a stop.
If there's a leak, there might not be as much reserve capacity as there should be. The pump will have to come on more often (which could shorten its life), or it might need more assist from the engine if it's a vacuum system.
My last car had a very slight leak in the boost reservoir. Sometimes after it sat for a long time, like a day or more, I would start it up and there would be no power brakes. Whatever mode the engine was in when it started up sometimes wouldn't create enough vacuum until I started driving. But I would occasionally have no power brakes as I backed out of my parking space. Apparently the fix was a software change, presumably to get the engine to create more vacuum right away, but I never got around to having it done.
Some of the unintended acceleration problems come from the fact that when the throttle is all the way open (for whatever reason), the engine isn't creating much vacuum to assist the brakes. There should be enough braking power to bring the vehicle to a stop, but if you pump the brakes or if there's a leak, it won't work. Electric power brakes will work the same no matter what the engine is doing.
The parking brake can also be used to help stop the vehicle in an emergency. It's not ideal, and you should apply it slowly so you don't lock the rear wheels, but it helps.
Everyone who drives should know what to do when something goes wrong with their car. If power brakes or steering go out, they need to know it will take a lot more force to operate those systems. Sure, sometimes it might be physically impossible, but I get the sense that some people out there have no idea that if the brakes "stop working" you need to press the pedal as hard as you physically can (see the first post in this thread, for example), and then at least you have a chance of stopping. If the brakes still don't work, downshift to the lowest gear, apply the parking brake, etc. If you're going 75 on the highway, it's unlikely that you will have to come to a stop for something in front of you, so you have plenty of time to slow down, move to the shoulder, and eventually come to a stop.
BlackWorksInc
New member
But she does, because the brakes still function hydraulically; she just doesn't have any assistance.
What do you expect exactly? For them to run two Vacuum brake boosters, or two Hydraulically Assisted Master Cylinder Units, or any combination of the two? Just the engineering and cost alone would make the SUV ridiculously expensive, its the same with power steering; when it goes out on a 6,000lbs vehicle its hard to turn... BUT you still can turn it.
As [MENTION=113611]m85476585[/MENTION] stated there are manual back-ups in vehicles for a reason, they are by no means easy to use; but in an emergency its all you got if everything takes a dump! Hell I agree with him, every single person operating any vehicle should be trained in how to manage possible emergency situations, otherwise in my opinion they have no business operating a multi-ton potential death trap (because that is what all vehicles are in the hands of the uninitiated, be they soccer moms or teenagers) due to incompetence. It is the operator's responsibility to control their vehicle at all times, we don't shirk responsibility because a pilot lost his aileron; we expect him to know how to land that damn plane to the best of his abilities in all situations, because it is his responsibility to be trained and understand how to operate his vehicle in all conditions. Yet there's so many incompetent, uninformed, and/or inexperienced drivers of varying ages, genders, ect. that have no idea how to operate their vehicles and in an emergency they injury/kill/damage others because they are operating a vehicle beyond their abilities. I'm not going to go too much more deeply into this as it becomes somewhat political and opinionated; but basically the fact we pretty much hand out driver's licenses and allow people who have no business being behind the wheel of such dangerous machines absolutely makes me paranoid and shows me how little responsibility the general public takes in being responsible operators of such potentially deadly things!
I'm not going to say the 3rd Gen wasn't a good SUV, but the reality is that you had a good experience with your vehicle and I won't fault you for that. But between injector issues in older units, head gaskets, sludging, wear and tear, ect. in most 3rd gens I see; they are far from being "the perfect SUV." Not to mention as was stated above, their vacuum system is prone to failure because of its dependence on engine vacuum. I have heard plenty of stories of various makes and models having vacuum boosters failing; but then again we're talking about an extremely rare phenomenon, we can't exactly say "just because it never happened to me or my 6 degrees of separation it will never happen." It'd be like saying "EVERY 4th gen WILL have Headgaskets that fail because a small subset of them DO fail" or "because .5% of 4th gens catch fire (this is made-up by the way as far as I know...) all 4th Gens will catch fire!" As I said before, your particular failure was such a rare occurrence among most brake system failures that its unfair to go around telling everyone that their brakes are going to kill them; it just becomes the same fear mongering people did when the "Unintended Acceleration" crap was popular.
Again I am not trying to put you down or anything, I'm just trying to point out that its unfair to be upset with a manufacturer because the vehicle operated as designed in a fail-safe situation; you could say that because the automatic transmission failed internally and went into "limp-home" mode and defaulted to 2nd gear that it is dangerous (and it can be) but you still can crawl the vehicle to safety vs. being just straight stranded. Or how about if the throttle body completely craps out on you? Instead of being stuck OPEN it is spring loaded shut to prevent run-away engines (this could be bad if you've lost power suddenly), so at the very least you're not flying down the freeway all the sudden. There's also the fact that if your entire vehicle craps out electrically you still have the ability to turn the steering wheel, apply the brakes (at this point even your vacuum brakes will run out of reserve depending on how much braking you're doing), and pull the vehicle to the side of the road. There are a LOT of fail-safes built into a vehicle and many of them are harder to operate when s*** hits the fan, but they at least give a trained, responsible operator the tools to take control of essentially a very dangerous brick hurtling down the road.
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One could argue that the fail-safe mode isn't safe enough. Maybe the brake booster could warn you sooner if it is failing, such as if it detects a slow reserve pressure leak, or if the motor starts running at an unusual temperature or something. It could keep you from driving the car if it detects any problem in the brake system, but I'm sure that would generate complaints. Or maybe it could deploy emergency parachutes out the trunk?
Aircraft have fully redundant hydraulic systems, and they have to be light enough to fly. But they are bigger and more expensive than passenger vehicles, and there's almost no chance of control without the hydraulic systems working. In a car at least you can coast to a stop.
I'll admit I've never tried to stop a 4runner without power brakes, but now I want to try it. Next time I have a chance to find an isolated road, I'll see what happens trying to stop using only the parking brake and engine braking. I'd really like to see what it's like with the power assist disabled, but it would be somewhat unsafe to test except on a closed course, and it would probably throw codes that I would have to deal with. I'm more worried about upsetting the computer than about the safety of it since I could probably find a quiet enough road.
