yep... that is the sound we heard -- it just kept going and going.
Complete Brake Failure -- Thanks Toyota!
- Thread starter dpr422
- Start date
yep... that is the sound we heard -- it just kept going and going.
It is a variable pressure electronic system. I am not an expert on THIS, but it is normal for a system such as this to cycle.
Someone *cough, cough, Toyota tech* should let us know what is normal. I hear my system cycle when I first turn my truck on. I consider it totally normal as it builds the system up to operating pressure.
Someone *cough, cough, Toyota tech* should let us know what is normal. I hear my system cycle when I first turn my truck on. I consider it totally normal as it builds the system up to operating pressure.
mrrab
New member
Concur.
BlackWorksInc
New member
Wait is that my cue to provide useful information? LoL :nerd:
Yes it is normal for the unit to cycle. It uses hydraulic pressure rather than vacuum so you will hear it cycle every now and then. When you first start the vehicle, it will cycle for roughly 20-40 seconds and after a few brake pedal uses it will cycle on again to build up pressure.
Sorry for hijacking the thread...but...
You guys need to get out somewhere with you vehicles and try it...the parking brake on most modern cars/trucks don't have the 'leverage' that older cars/trucks had...why? Because of rear disc brakes. Older cars/trucks used the same brake shoe as the regular brakes for the parking brakes. Vehicle like the 4th gen 4runner use the hub of the rear disc for the parking brake with a brake shoe about 1/4 the of the size had the 4runner come with rear drum brakes (as do most other vehicles).
Plus, depending one the vehicles configuration and weight bias...yes, the parking brake will slow you down and stop...eventually...but in no way will it 'stop' you in the same manner as regular breaks...especially if they are not adjusted properly. Who here uses their parking regularly and is 100% sure they are adjusted properly...will it hold your 4runner on a hill??? One some vehicles (especially older vehicles with the 'hand brake'), the parking brake will lock up the rear wheels...but you could be introduced to some nasty oversteer and be worse off. My first car was a stick...those of you who know and have driven a stick shift can attest that using the parking brake in this manner can be fun...and dangerous.
Yes, there is the back up...it is called dual master cylinder...while not impossible, it is rare for both cylinders to go out like the OP here.
But I do agree...do what you can to stop a vehicle (with no brakes) as soon and safely as possible...the parking brake can be an option...just don't call it an emergency brake and don't rely on it to save you in an "emergency".
And this whole thing about the government??? Anyone here heard about the difference between the federally owned Grand Canyon vs. the Native American owned Grand Canyon...but that's another thread...
bluemarlin04
New member
I tired it. Seemed to work OK going parking lot speeds. Now if I was flying down the highway I might think twice about smashing the brake. But, if you really lose all pressure you're really not left with any options short of coasting or putting the trans in park.
Bossman
Senior Member
I'll add in my recent experience with a complete brake failure - 2003 Limited V8 with 150,000 km.
Was driving in city traffic when the brake warning (red) indicator lit up on the dash. I did not notice any major difference in braking power the first few stops after this indicator came on.
Then as I continued additional warning (orange) indicators lit up - I believe they were the ABS, TRAC and VSC - accompanied by a high pitched audible warning.
When I went to depress the brake pedal, it went to the floor with little resistance. As I was approaching stopped traffic, I had to quickly take evasive action by changing lanes and then bailing into a nearby parking lot - all the while applying the parking brake during this emergency.
Fortunately, the parking brake did eventually bring me to a complete stop. I was able to avoid contact with any other vehicles or pedestrians, and no body damage was done to my T4R.
Shaken by this experience, I immediately called my local Toyota dealership. A towing company came to the parking lot and using a flatbed my T4R was brought to the dealership. While waiting for the tow, I looked under the hood and observed the brake fluid reservoir to be completely empty - had been fine the last time I checked it.
Once up on the hoist at the dealership, the cause was found to be a failed brake line just above the rear axle on the driver's side. Cause of the failure was attributed to corrosion (we use a lot of road salt up here during the winter).
My T4R is still at the dealership awaiting the arrival of new brake lines.
Returning home, there was no evidence of any leak in the driveway from the area that the brake line failed. Thus, a catastrophic failure!
Was driving in city traffic when the brake warning (red) indicator lit up on the dash. I did not notice any major difference in braking power the first few stops after this indicator came on.
Then as I continued additional warning (orange) indicators lit up - I believe they were the ABS, TRAC and VSC - accompanied by a high pitched audible warning.
When I went to depress the brake pedal, it went to the floor with little resistance. As I was approaching stopped traffic, I had to quickly take evasive action by changing lanes and then bailing into a nearby parking lot - all the while applying the parking brake during this emergency.
Fortunately, the parking brake did eventually bring me to a complete stop. I was able to avoid contact with any other vehicles or pedestrians, and no body damage was done to my T4R.
Shaken by this experience, I immediately called my local Toyota dealership. A towing company came to the parking lot and using a flatbed my T4R was brought to the dealership. While waiting for the tow, I looked under the hood and observed the brake fluid reservoir to be completely empty - had been fine the last time I checked it.
Once up on the hoist at the dealership, the cause was found to be a failed brake line just above the rear axle on the driver's side. Cause of the failure was attributed to corrosion (we use a lot of road salt up here during the winter).
My T4R is still at the dealership awaiting the arrival of new brake lines.
Returning home, there was no evidence of any leak in the driveway from the area that the brake line failed. Thus, a catastrophic failure!
BlackWorksInc
New member
Wow, that's a scary story right there...
I don't understand why we cannot find something that doesn't damage vehicles as badly as road salt compounds do. If you had gotten in an accident or worse, who would be at fault? Toyota because its their vehicle or the City/State for using a corrosive compound that damaged your vehicle's system to the point of catastrophic failure? I understand the need to keep roads safe, but its not like the State is compensating you for damaging your vehicle in the name of safety?
I'm glad everything turned out okay, I've had a vehicle with so much air in the lines that there was no braking force and that was only going 5mph and it scared me. Can't imagine the level of anxiety at around 35mph!
I don't understand why we cannot find something that doesn't damage vehicles as badly as road salt compounds do. If you had gotten in an accident or worse, who would be at fault? Toyota because its their vehicle or the City/State for using a corrosive compound that damaged your vehicle's system to the point of catastrophic failure? I understand the need to keep roads safe, but its not like the State is compensating you for damaging your vehicle in the name of safety?
I'm glad everything turned out okay, I've had a vehicle with so much air in the lines that there was no braking force and that was only going 5mph and it scared me. Can't imagine the level of anxiety at around 35mph!
Rattlecanpaint
New member
As a tech with 11 years of experience, I've never seen a complete brake system failure. It's certainly possible as it's man made and anything man made can fail.
First, to the OP. The complete failure you had is probably NOT related to the previous issue you were having. (ABS) It sounds to me like the seals in the master cylinder simply gave up the ghost. (Basically when you press the brake pedal, you are putting pressure on a hydraulic cylinder that then moves brake fluid through the lines to the brake calipers which also have pistons in them to squeeze pads against the rotors.) These pistons have rubber seals on them to "seal" the fluid in the system and this is more than likely what failed. It's one of those things that will probably never give you any warning that it's going bad and is certainly not something that can be easily checked at any point. It's also something that will more than likely never happen to you again in your lifetime. Props to your daughter for getting the car stopped. She learned a valuable lesson that day. (As did you I'm sure).
As for the parking brake thing. Remember having a coaster brake on your bicycle as a kid? What happened when you hammered that thing? You skidded sideways and in some cases fell over and skinned up your knees. Parking brakes are only on the rear wheels so the same thing will happen to you if you just lock up those rear brakes. You skid out of control and skin up your car. This is more than likely why they are now not strong enough to lock up the tires but slow you down gradually.
First, to the OP. The complete failure you had is probably NOT related to the previous issue you were having. (ABS) It sounds to me like the seals in the master cylinder simply gave up the ghost. (Basically when you press the brake pedal, you are putting pressure on a hydraulic cylinder that then moves brake fluid through the lines to the brake calipers which also have pistons in them to squeeze pads against the rotors.) These pistons have rubber seals on them to "seal" the fluid in the system and this is more than likely what failed. It's one of those things that will probably never give you any warning that it's going bad and is certainly not something that can be easily checked at any point. It's also something that will more than likely never happen to you again in your lifetime. Props to your daughter for getting the car stopped. She learned a valuable lesson that day. (As did you I'm sure).
As for the parking brake thing. Remember having a coaster brake on your bicycle as a kid? What happened when you hammered that thing? You skidded sideways and in some cases fell over and skinned up your knees. Parking brakes are only on the rear wheels so the same thing will happen to you if you just lock up those rear brakes. You skid out of control and skin up your car. This is more than likely why they are now not strong enough to lock up the tires but slow you down gradually.
I've had a break line break on me that pretty much rendered the brakes useless...but it was on a super old truck and probably my fault for not maintaining it. But serious almost soil yourself moment when coming up to a stop sign. Luckily for me there were no cars going through the intersection because i wan't stopping at all.luckily it was a manual and I could downshift and turn the car off and let it cough to a stop. Scary stuff though.
Brian757
New member
Haha, same thing happened to me about 5 years ago. I had a failed brake piston in my front passenger caliper and it bled brake fluid until I went empty.
I was going 45MPH towards a red light, full of traffic. I had to fly up onto the sidewalk and take a right turn at about 30MPH, thankfully no one was in that lane. I must've looked drunk as hell. I flew up onto the grass and sidewalk and then about idled my way into a parking lot. I got out and brake fluid was all over my passenger tire, with the brake fluid reservoir empty.
I had never been that scared in my life.
earthrealm
Senior Member
a pal of mine has a similar problem, his MC failed and a refurbished unit was installed 3 weeks ago...the brake functioned fine till last wkend. now the brake pedal is very stiff nand the reservoir overflowed..splashing brake fluid everywhere. also the brake light ans aBS sign light is on. tried pumping the pedal with the ignition off [to depressurize the system], no change was observed in the pedal..it still remained as stiff as before..
apart from a possible failure of the recently installed MC+hydrobbost unit........what else could be possibly wrong?....dont comprehend why the brake pedal will be stiff n yet refuse to hold.
apart from a possible failure of the recently installed MC+hydrobbost unit........what else could be possibly wrong?....dont comprehend why the brake pedal will be stiff n yet refuse to hold.
2003 4Runner with 212K miles - similar problem
High pitched whine, four brake-related lights illuminate (ABS, brake, two VSC Trac lights). The whine is only in the cabin. It happened intermittently and couldn't be replicated. Braking system checked out - no problem noted, but now it's constant and we have no power-assist brakes. The car will be at the repair shop tomorrow. More to follow...
High pitched whine, four brake-related lights illuminate (ABS, brake, two VSC Trac lights). The whine is only in the cabin. It happened intermittently and couldn't be replicated. Braking system checked out - no problem noted, but now it's constant and we have no power-assist brakes. The car will be at the repair shop tomorrow. More to follow...
This is very true.
There is a lot of negative feedback in this post, some with valid reason, and some just to be mean. The fact is, given the circumstances (failure or not), no one was hurt, so we should be thankful for that.
Hopefully no one freaked out and was like, "OMG 4runners are shit" because these really are incredibly strong, reliable, and safe trucks. I would let my daughter drive mine any day of the week without worry.
Bossman
Senior Member
Round 2!
Driving on a local highway today at 90 km/h, coming up to set of traffic lights that turn amber. Thought best not to run the light, so stepped on the brake pedal. As I am depressing the pedal I hear a noticeable pop, then the pedal goes to the floor with little resistance. I'm coming up on the now red light fast!
Fortunately there was an advance turn signal for the cross traffic, so was able to make a hard right turn at the lights from the right lane that I was travelling in. Downshifted into neutral, pressing the parking brake and then bailed onto the shoulder.
Luckily I was able to avoid all pedestrians and vehicles in the area.
After getting it stopped, taking a deep breath and calming my nerves, climbed out of the 4Runner to see what was up. Brake fluid all over the driver's side front wheel and wheel well. A line had blown in behind the wheel.
Vehicle towed to local independent garage for repairs on Monday.
BlackWorksInc
New member
Weird, you don't hear about brake lines breaking much anymore. The ones I have heard are usually lifted vehicles running stock (shorter) lines still.
