Ayune
SILVER Star
Sounds like all they need is one well-written formal petition. So far there’s 107 ‘voted’ failures in this thread. That’s a pretty compelling case.
Poll on total brake failure in 100 series
- Thread starter e9999
- Start date
Definitely worth a shot. I know some people will say that this is a small community of enthusiasts and therefore only a small amount of rigs are experiencing brake failure. But really, this group of enthusiasts is a sampling overall of everybody who drives a Land Cruiser or Toyota product. So you can imagine if 83% of the people on here haven't experienced brake failure ( that number won't be totally accurate because many of them are not the original owners and have no idea what maintenance was done prior) but 13% have. Then you think what, maybe 1000 people who currently own 100 series are actually on the forum. A little over half have voted, others like me are just watching. Think of how many thousands of other owners are out there who have no idea this forum exists or that it could be a common problem. How many of them have had brake failure? 13% is a lot when you consider how big a deal no brakes can be !
If I was doing it again, and buying a high mileage truck north of say 150k miles. Swapping out the sub assembly brake booster part and doing the $70 rebuild would be VERY high on my list of baselining the truck. WAY before t-belt. Part was $1100 from cruiserparts.net or cheaper overseas EBAY.
I was luckly enough to have the alarms happen few miles from work and still had brake pressure. Engine off, at work parking lot. I went to pump the brakes like I'd be bleeding the system. the 40 times the FSM says to pump....I pumped 3 times and brake pedal went to the floor. Really lucky I didn't have my family with me when this happened. I live in a hilly area of San Diego.
I saved my old booster assembly to get rebuilt and leave it on the shelf for the next rainy day in 190k miles later
I was luckly enough to have the alarms happen few miles from work and still had brake pressure. Engine off, at work parking lot. I went to pump the brakes like I'd be bleeding the system. the 40 times the FSM says to pump....I pumped 3 times and brake pedal went to the floor. Really lucky I didn't have my family with me when this happened. I live in a hilly area of San Diego.
I saved my old booster assembly to get rebuilt and leave it on the shelf for the next rainy day in 190k miles later
Haven't experienced failure yet at 210k miles, but should we work together to file a recall petition with the NHTSA?
Motor Vehicle Defects and Safety Recalls: What Every Vehicle Owner Should Know | Safercar.gov | NHTSA
Motor Vehicle Defects and Safety Recalls: What Every Vehicle Owner Should Know | Safercar.gov | NHTSA
Luckily, my failure happened as safely and "conveniently" as possible. Towed my RZR to the other side of ATL and back one weekend and had no issues. Started the truck Monday morning ( the next day) to head to the office, and the death beep immediately started. No brakes at all. I ended up ordering a rebuilt motor and swapping it myself. I can't imagine the outcome if my brakes had failed while towing on I-285. Mileage was around 115,000 at the time.
I had a failure but not associated with what the OP posted I don’t believe, so I’d thought I’d post it to see if anyone else has experienced it. While coming down a very long steep grade in Utah back country and having to use my brakes a lot more than I felt comfortable with , I lost my brakes without warning . I was able to pump them up with several quick pumps but it would go to the floor on the initial pedal push. We diagnosed it as the brake fluid boiling from possible excess water in the fluid and excessive heat build up from riding the brakes. I let it cool as long as I could then geared down like I should have done at the top of the grade , but after getting to camp, I opened the hood and did all I could to get the fluid cooled down. After it did the next morning my brakes seemed ok . When I got home I checked the pads front and rear and they were all thin and needed replaced ASAP which I did. I still need to bleed the system but do believe this failure was a result of heat from the thin pads and moisture in the system causing the fluid to boil and become useless with no lights or warnings of any kind.
It would be good to re-do this poll, asking which year the truck was, as opposed to how many miles it had. I think that might help narrow down which model years are more prone to the problem.
But yeah, everybody wants to do the petition to the NTHSA but has anybody?
But yeah, everybody wants to do the petition to the NTHSA but has anybody?
- Joined
- Mar 23, 2013
- Messages
- 96
Partial brake failure at 320,000 miles. ABS motor went after one or two warnings (brake light, abs light, motor grinding loudly). I still had manual control over the rear brakes, probably 20% of braking power, if that. It was definitely scary in an almost three ton vehicle.
Edit: 99 LC
Edit: 99 LC
Glad it turned out OK.
A suggestion for all of us:
Keep your parking brake in good working condition. It won't stop you fast, but might contribute to any primary brakes you still have. Don't forget to use engine braking (transmission downshifting). These are all things that should be thought about before they are needed. If you don't have a 'plan' in your head...things might turn out badly.
Also, IF you can't stop....look for a place to 'ditch' your vehicle that results in the least amount of damage to you and your surroundings. You can still steer.
So, after following this thread for a while, I finally had the brake failure happen. Just a couple of words incase anyone is at the point where I was a few months ago.
First, the truck pulled to one side a bit when braking somewhat hard. This follows months of hearing the motor turn off and on while under normal driving conditions (making a kind of sound like a low volume cymbal or high hat drum being rattled for about 5 seconds). I had the brake fluid flushed by a local mechanic to see if that would help after reading threads here about trying that. Sounded and drove the same. Didn’t notice anything better.
Then, when driving home from the gym, I had about 20 seconds of a screetching noise. That would stop when pumping the brake pedal. All brakes worked fine still. Then the screeching stopped for about 30 seconds. That’s when the brake light and alarm went off. Brakes still worked fine and I was only about 2 miles from home at night when the roads were empty.
Truck is a 98 w 167k miles.
First, the truck pulled to one side a bit when braking somewhat hard. This follows months of hearing the motor turn off and on while under normal driving conditions (making a kind of sound like a low volume cymbal or high hat drum being rattled for about 5 seconds). I had the brake fluid flushed by a local mechanic to see if that would help after reading threads here about trying that. Sounded and drove the same. Didn’t notice anything better.
Then, when driving home from the gym, I had about 20 seconds of a screetching noise. That would stop when pumping the brake pedal. All brakes worked fine still. Then the screeching stopped for about 30 seconds. That’s when the brake light and alarm went off. Brakes still worked fine and I was only about 2 miles from home at night when the roads were empty.
Truck is a 98 w 167k miles.
- Joined
- Aug 22, 2014
- Messages
- 66
Has anyone confirmed if the sticky brake pedal is a precursor to total brake failure? I make a 2,000 mile trip in the LC with the family several times a year on top of daily driving. At 200k+ miles, and a sticky brake pedal, I'm starting think it's a only a matter of time.
Mine failed suddenly at about 337k. Lights, buzzers, etc., and absolutely no pressure in the system. I was backing out my driveway, which is downhill, as the buzzer came on, and realized I didn't have brakes as I was heading towards a car on the other side of the street. I shifted into D, and applied a little throttle, enough to engage the converter, so I could arrest backward progress. Hopefully the trans wasn't damaged, but in the moment, that was the solution I reacted with. It seemed okay, as I crept VERY slowly back up the driveway, using gravity to help me coast to a stop, and at that exact moment it wasn't rolling forward, I shifted into P. I've pulled the assembly out now, and am about to disassemble it and try the motor rebuild. I think it's a good time to rebuild the cylinder, too, especially if it's only $50 or so for the kit. I am either going to get the motor rebuilt locally, or more likely, trust the guys at ACC Garage to do it. They have been great with advice via e-mail.
Just curious if anyone here has a way to confirm if the hydraulic actuator is the problem vs master cylinder or pump motor?
My mechanic said a sure sign is that the pedal doesn’t return properly. Is that what you mean by sticky pedal?
Total brake failure happened today, 2006 LX470 with 175k miles. Luckily it was just in a parking lot, but we were fully loaded ready to go camping. Good thing you didn't happen 4 hours later or we would have been a LONG way from help.
So glade everyone is okay. Fortunately that always seems the case!
Also when you say total brake failure what happen, in detail please? What first alerted you? Then what happened?
Typically sudden brake failure, where pedal goes to the floor. Is booster motor failure. Alarm and dash lights go on and we get 1, 2 or 3 strokes (each weakening) before pedal goes to the floor after motor failure. This is due to loss of booster pressure, because booster motor failed to run. Motor failure!
There is also certain very rare condition where no power (12V) gets to the motor. So motor is good, just no current to run it.
The accumulator can fail but usually a slow death.
If a brake fluid leak developed and fluid is lost, the same thing happens, in we've no pressure. We can have a line leak and still have brake in other three wheels. I've seen where reservoir has totally emptied. No brake fluid no brakes. But here alarm should sound very early on, Just as level drops below low line. Failure happens when empty.
A small leak will result in pressure loss. This will activate booster motor excessively. Someone that rides there brake or a tail gate-er or heavy stop and go traffic using brakes often. This all uses motor more than HWY miles of a proper service brake system. So mileage is not a good indicator of life of motor.
I'm most interested in the wire from bottom of your ABS (black unit on side of brake master) that runs to the booster motor. I find ~30% of these wires corroded. In all failure I've repair, the wire was corroded. I've a theory, that the wire being corroded is increasing resistance. This a non reusable wire according to factory. This 8 " two wire harness list for $170, I kid you not. It's because it's a resistance wire. My theory is, this is leading to early failure of the motor from increase in resistance. In some cases, wire may be responsible, for failure of ABS unit, which current flows through.
My interest in this is in trying to inspect for failure before it happens. In that, the corroded wires may mean we need to replace wire and rebuild motor when we find this. The more cases I find with failure and a corroded wire associated to it, the stronger my theory becomes.
So please report back with detail and pictures.
Here some pictures of the wire corroded. In ~30 % of 100 I inspect, I found the brake fluid reservoir was over filled. Shop top brake reservoir without reading instruction embossed on reservoir on how. I suspect brake fluid gets into the wires boot, attracting moisture.
1999 w/150Kmiles from CO
2007 w/100K from GA/TX. Inspection with mirror.
07 after wire & screw clean up. You can see reservoir if you look close to orient yourselves as to wires location.
2005 w/85k miles from SoCA
I also just inspected a 2000 LX very clean with 200K miles. It also had corrosion on wires.
I've a 2000LX w/350K miles and some undercarriage rust and bolt rust in engine compartment, as came from CN and Boston. Wires are not corroded. So it does not seem to matter the climate the rig was in or the age or the mileage. It also does not matter if engine washed. As my 01 w/160K miles was washed so much over 13 years you could eat off the engine. So why are some corroding! Brake fluid is my theory from over filling. Book stated do not over fill.
I'd be very interested in what you find is cause.
Also when you say total brake failure what happen, in detail please? What first alerted you? Then what happened?
Typically sudden brake failure, where pedal goes to the floor. Is booster motor failure. Alarm and dash lights go on and we get 1, 2 or 3 strokes (each weakening) before pedal goes to the floor after motor failure. This is due to loss of booster pressure, because booster motor failed to run. Motor failure!
There is also certain very rare condition where no power (12V) gets to the motor. So motor is good, just no current to run it.
The accumulator can fail but usually a slow death.
If a brake fluid leak developed and fluid is lost, the same thing happens, in we've no pressure. We can have a line leak and still have brake in other three wheels. I've seen where reservoir has totally emptied. No brake fluid no brakes. But here alarm should sound very early on, Just as level drops below low line. Failure happens when empty.
A small leak will result in pressure loss. This will activate booster motor excessively. Someone that rides there brake or a tail gate-er or heavy stop and go traffic using brakes often. This all uses motor more than HWY miles of a proper service brake system. So mileage is not a good indicator of life of motor.
I'm most interested in the wire from bottom of your ABS (black unit on side of brake master) that runs to the booster motor. I find ~30% of these wires corroded. In all failure I've repair, the wire was corroded. I've a theory, that the wire being corroded is increasing resistance. This a non reusable wire according to factory. This 8 " two wire harness list for $170, I kid you not. It's because it's a resistance wire. My theory is, this is leading to early failure of the motor from increase in resistance. In some cases, wire may be responsible, for failure of ABS unit, which current flows through.
My interest in this is in trying to inspect for failure before it happens. In that, the corroded wires may mean we need to replace wire and rebuild motor when we find this. The more cases I find with failure and a corroded wire associated to it, the stronger my theory becomes.
So please report back with detail and pictures.
Here some pictures of the wire corroded. In ~30 % of 100 I inspect, I found the brake fluid reservoir was over filled. Shop top brake reservoir without reading instruction embossed on reservoir on how. I suspect brake fluid gets into the wires boot, attracting moisture.
1999 w/150Kmiles from CO
2007 w/100K from GA/TX. Inspection with mirror.
07 after wire & screw clean up. You can see reservoir if you look close to orient yourselves as to wires location.
2005 w/85k miles from SoCA
I also just inspected a 2000 LX very clean with 200K miles. It also had corrosion on wires.
I've a 2000LX w/350K miles and some undercarriage rust and bolt rust in engine compartment, as came from CN and Boston. Wires are not corroded. So it does not seem to matter the climate the rig was in or the age or the mileage. It also does not matter if engine washed. As my 01 w/160K miles was washed so much over 13 years you could eat off the engine. So why are some corroding! Brake fluid is my theory from over filling. Book stated do not over fill.
So this is the sequence of events as to the best of my memory. Everything was working fine, brakes felt normal on the way to the ice store to pick up dry ice for the weekend camping trip. I was loaded up with all gear and my two boys in the back seat and since this was the first trip with the new car, I was curious if I would get any reaction from the AHC (I have not checked pressures yet since I bought the car in December).
Side Note: I do remember that the brake fluid level was above max after I took it to service @ Lexus dealership, so you might be on to something about the brake fluid corroding the wire connection.
As I pulled into the parking lot, it seemed like I heard a crunching sound coming from the drivetrain, but thinking back it mayI have been the crumbling cement under the tires. I pull in, reverse to position the car to pull into a parking spot and warning lights appear and go crazy complete with the high pitch warning tone. I immediately think its the transmission, transfer case or the differentials since I heard a crunching noise before. There are no fluids leaking, and at this time I learn that there is no transmission dipstick to check fluids (hahaha). So I then try to shift transfer case into N and L, still trying to diagnose what I thought was a drivetrain issue. I put the gear back to H but the transmission was having some trouble going back into P. I got it there with more force and a little grinding (oops!). After walking around the car again scratching my head in confusion, I got back in and started reversing a little, then driving forward, reversing thenout of nowhere with no indication, the brake pedal goes to the floor. By pressing hard at the end of the pedal stroke I could feel a very small amount of brakes, but not even enough to stop the car from rolling fwd when in D. I used the hand brake to stop and started searching the internet and I came to realize that "I was experiencing what I have seen every day at the top of 100-series forum on ih8mud!"
Anyway, I will definitely ask to keep all the parts the dealer removes and post pics when I see them, or report back any news.
Side Note: I do remember that the brake fluid level was above max after I took it to service @ Lexus dealership, so you might be on to something about the brake fluid corroding the wire connection.
As I pulled into the parking lot, it seemed like I heard a crunching sound coming from the drivetrain, but thinking back it mayI have been the crumbling cement under the tires. I pull in, reverse to position the car to pull into a parking spot and warning lights appear and go crazy complete with the high pitch warning tone. I immediately think its the transmission, transfer case or the differentials since I heard a crunching noise before. There are no fluids leaking, and at this time I learn that there is no transmission dipstick to check fluids (hahaha). So I then try to shift transfer case into N and L, still trying to diagnose what I thought was a drivetrain issue. I put the gear back to H but the transmission was having some trouble going back into P. I got it there with more force and a little grinding (oops!). After walking around the car again scratching my head in confusion, I got back in and started reversing a little, then driving forward, reversing thenout of nowhere with no indication, the brake pedal goes to the floor. By pressing hard at the end of the pedal stroke I could feel a very small amount of brakes, but not even enough to stop the car from rolling fwd when in D. I used the hand brake to stop and started searching the internet and I came to realize that "I was experiencing what I have seen every day at the top of 100-series forum on ih8mud!"
Anyway, I will definitely ask to keep all the parts the dealer removes and post pics when I see them, or report back any news.
Thanks, good recall!. You did the right thing investigating after alarm sounded, from a parking spot.
I'm very interested in your old parts and would like to have them.
I've been tearing down to investigate, any I can get my hands on.
Highlights:
History;
- No mention of inspecting a recently purchased 13 yr old w175K (06LX)
- Lexus Dealership recent serviced (unknown for what, likely O,F&L).
- Brakes reservoir observed overfilled.
- No known brake fluid leaks.
- Strange sound heard before brake alarm. May be just tires on loose cement/gravel.
- Brake warning. Dash lights & alarm sounded. Presumably while foot on brake pedal bleeding off brake system assist pressure, as was reversing into parking spot.
- Continued using brakes. While trying to diagnose sound, shifting through transmission gears and transfer case. Presumably foot on brake pedal.
- Started and stop engine (IG key off and on), presumably. More times foot on brake pedal.
- Minimal brake at bottom of pedal, after pressing pedal multiple times after alarm sounded.
It also possible it was not the motor failure. But something else, or motor didn't get switched on. But most common based on your outline is motor failed to run. The why will take tearing down and inspecting.
Assuming reservoir still has fluid (no leak). Dealership will likely do one of two things. Replace booster assembly $1.5k to $2.5K or replace entire brake master assembly with booster $4k to $5K. In some cases you get a mechanic that digs to find that one component $500 to $2K, but not often. They will use new OEM parts only at Toyota or Lexus Dealership.
Often we've read here sudden and without warning. That is unlikely. It just drivers ignoring the warns. After parking for hours (over night) the pressure does bleed down some. So start-up is time we'd get least advance warning. But if pressure does not come up very quickly, alarm sound in that event also. If alarm broken or disabled then we still have dash lights.
When we turn IG key to ON. Listen and you'll hear a motor run. Many think this is fuel pump, it is not! It is your brake booster motor running bring up pressure filling accumulator.
I tell my GF: If alarm sounds or brake lights comes on or both. Pull to side of road and stop. Do not drive, just call me. It should not happen but; Be prepared to press pedal to the floor and use hand brake, along with downshift (engine braking) to reduce speed, then shift to N as speed drops too come to stop.
When we turn IG key to ON. Listen and you'll hear a motor run. Many think this is fuel pump, it is not! It is your brake booster motor running bring up pressure filling accumulator.
I tell my GF: If alarm sounds or brake lights comes on or both. Pull to side of road and stop. Do not drive, just call me. It should not happen but; Be prepared to press pedal to the floor and use hand brake, along with downshift (engine braking) to reduce speed, then shift to N as speed drops too come to stop.
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