Poll on total brake failure in 100 series (3 Viewers)
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I've read through all 48 pages of this post and it's gotten me nervous enough. I checked my car today.
2002 LX470 with 185K miles
The booster at start runs for 40 seconds but I noticed that there's 3 or 4x where it pauses for a quick second before continuing again. Connectors look perfect with absolutely no rust or corrosion.
Should I be concerned at all?
2002 LX470 with 185K miles
The booster at start runs for 40 seconds but I noticed that there's 3 or 4x where it pauses for a quick second before continuing again. Connectors look perfect with absolutely no rust or corrosion.
Should I be concerned at all?
I had my brake light come on last night. Thought it was the emergency brake and then I checked the master level. It was low and looked to be wet on the lower part of the black box on the driver side. Brakes have been working fine but now I obviously have a issue on my hands.
I just replaced the whole brake booster unit this morning. One of the easiest jobs for such a major component - 1.5 banana job. Helps that it's the whole unit.
If you're watching the video in post #900 not sure if it's the difference in models (mine's a 2006) but there's no need to remove any of the kickpanel/undershield pieces inside. You can get to everything without a problem (ABS unit, pedal pin, booster bolts). This model is also easier because you don't have to deal with the charcoal canister that is just forward of the booster, and all the related plugs and hoses.
Glad to have brakes again. But with 100deg weather and soaring gas prices, now she sits
If you're watching the video in post #900 not sure if it's the difference in models (mine's a 2006) but there's no need to remove any of the kickpanel/undershield pieces inside. You can get to everything without a problem (ABS unit, pedal pin, booster bolts). This model is also easier because you don't have to deal with the charcoal canister that is just forward of the booster, and all the related plugs and hoses.
Glad to have brakes again. But with 100deg weather and soaring gas prices, now she sits
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I would be, as this was the start of mine failing. I noticed that the motor was running a little longer at start up, and starting to come on more often. I didn't think too much of it as brakes seemed fine. We left on a 3k mi trip, at the half way mark it was coming on a lot so I flushed the brakes to see if that would help. It helped a little during heavier braking (downhill), but it was still coming on more than I liked. I ordered the parts to rebuild the master cylinder and replace the booster. Then one morning after our trip but before the parts came in the pump stayed on almost constantly, and when I pressed the pedal sometimes there was not enough pressure... so I parked it.
I rebuilt the master cylinder and replaced the entire booster. This would normally be a very easy job if you are mechanically inclined. - Mine, not so much.
The master cylinder was extremely difficult to take apart due to a gouge from the factory. The gouge was above the seals,but prevented it from coming apart. Once I cleaned that up it all went back together just fine. - Once rebuilt the brakes have worked just fine; the motor runs once at start up, and not that often the rest of the time.My recommendation is to replace the booster and rebuild the master cylinder before you have any more issues. I believe you are experiencing symptoms of the beginning of the end. Good luck.
- Thread starter
- #947
Not related to posts directly above, I'm thinking that it would be great if somebody knowledgeable would clarify what exactly "motor running too much" means in terms of how often, how long, when, where the noise is coming from, etc. Heck, it would be great if somebody would record the sound and post it here, so that anybody not expert on this has a good reference to work with. Like, "here is a normal sound" and "here is a warning sign". That would be very helpful, and may save somebody from trouble.
I just replaced the whole brake booster unit this morning. One of the easiest jobs for such a major component - 1.5 banana job. Helps that it's the whole unit.
If you're watching the video in post #900 not sure if it's the difference in models (mine's a 2006) but there's no need to remove any of the kickpanel/undershield pieces inside. You can get to everything without a problem (ABS unit, pedal pin, booster bolts). This model is also easier because you don't have to deal with the charcoal canister that is just forward of the booster, and all the related plugs and hoses.
Glad to have brakes again. But with 100deg weather and soaring gas prices, now she sits
View attachment 3034822
***Sorry, created a new post here so not to pollute this one with noise:***
Post Booster Replacement - ABS/VSC Lights with Codes
So after this replacement, now I'm trying to get my ABS/VSC lights to turn off. Warning sound and brake light have stopped. Booster assembly was done following the instructions posted by many. "Manual" flush then Techstream for all four corners to activate the ABS solenoids. After bleeidng with...
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Happy Father's Day mud fam,
So after this replacement, now I'm trying to get my ABS/VSC lights to turn off. Warning sound and brake light have stopped.
Booster assembly was done following the instructions posted by many. "Manual" flush then Techstream for all four corners to activate the ABS solenoids. After bleeing with clear fluid and no air, LC brakes great. But I have the ABS and VSC lights that won't turn off nor will it clear them using Techstream.
I have the following:
C1223 - ABS Control System Malfunction
C1233 - Open/Short..Yaw Rate
C1244 - Open/Short...Decel Sensor
C1246 - Master Cylinder Pressure
I understand the C1223 is generic when anything in the ABS is not functioning downstream, so I'm guessing the C1246 is triggering this. Are there any troubleshooting procedures for any of these codes? Do they magically disappear after some driving? or have I done screwed something up?
The one thing I didn't do is drive on gravel as some have done to flex the ABS system but I figure that's what I was doing in TS for all four corners (4 seconds, resting, etc.) until all air and fluid ran clean.
Clearing DTCs in TS does nothing to these lights on the dash. They come on every time you start the car without pressing anything.
Any ideas?
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40 seconds is at the limit. The FSM recommends re-bleeding if over limit of 40 seconds.
Reason for long run time:
- Battery voltage low. Check voltage at cables first, and than on battery post. They should be the same. If not you've issue with battery terminals. Where something like oxidation is inhibiting current. If voltage the same, but low, say below 12V, we get a slightly longer run time. It's simple due to less power being delivered to booster motor. If voltage higher, say at 13V we get a shorter run time of brake booster motor. Due to motor turning faster. Corrosion on brake control wire, can also reduce current (increase resistance) to booster motor.
- Air in brake fluid system. Bleed and retest run time.
- Old brake fluid with high moisture contend. Result in less compressible fluid and lower boiling temperature of fluid. In this case, it simple takes longer to build pressure in fluid (compress fluid). Flush often!
- Leak. Leaks results in loss of pressure. This can cause brake booster motor to run excessively (longer than 40 seconds) and more often. Leaks can be external or internal.
- Bad flexible brake line. Damage of a flexible brake line at caliper, will flex or even get bubble/swells in the line. This too result in longer run times until pressure built.
If you checked/set fluid level after pump brake pedal 40 time with IG key off, and it was indeed low. And your seeing brake fluid around seal of ABS unit (black box on side of master) or the aluminium block between master and ABS unit. That was not spillage, or from being overfilled forcing out the cap. It is best to replace the whole Brake master with booster assembly. I've seen this a few times. There is seal plate between these. But Toyota will not sell to us, and leak may be internal.
Some have picked up used master and salvage the ABS unit and swapped in. But these is not recommended.
Post booster doesn't say much about what you did and with what. A little to open ended.***Sorry, created a new post here so not to pollute this one with noise:***
Post Booster Replacement - ABS/VSC Lights with Codes
So after this replacement, now I'm trying to get my ABS/VSC lights to turn off. Warning sound and brake light have stopped. Booster assembly was done following the instructions posted by many. "Manual" flush then Techstream for all four corners to activate the ABS solenoids. After bleeidng with...
Happy Father's Day mud fam,
So after this replacement, now I'm trying to get my ABS/VSC lights to turn off. Warning sound and brake light have stopped.
Booster assembly was done following the instructions posted by many. "Manual" flush then Techstream for all four corners to activate the ABS solenoids. After bleeing with clear fluid and no air, LC brakes great. But I have the ABS and VSC lights that won't turn off nor will it clear them using Techstream.
I have the following:
C1223 - ABS Control System Malfunction
C1233 - Open/Short..Yaw Rate
C1244 - Open/Short...Decel Sensor
C1246 - Master Cylinder Pressure
I understand the C1223 is generic when anything in the ABS is not functioning downstream, so I'm guessing the C1246 is triggering this. Are there any troubleshooting procedures for any of these codes? Do they magically disappear after some driving? or have I done screwed something up?
The one thing I didn't do is drive on gravel as some have done to flex the ABS system but I figure that's what I was doing in TS for all four corners (4 seconds, resting, etc.) until all air and fluid ran clean.
Clearing DTCs in TS does nothing to these lights on the dash. They come on every time you start the car without pressing anything.
Any ideas?
I've not had to deal with these C1233 - Open/Short..Yaw Rate C1244 - Open/Short...Decel Sensor. But I'd start there. First making sure the Brake CPU (bolt on near pedal and in the way when pulling master) wire hosing block plugged firmly. Also check that all wire blocks are fully plugged in master. Then set zero point.
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Solved mine, and it's actually quite embarrassing but I'll tuck my ego and tell.
The triangular connector which faces forward was inserted the wrong way. Orientation wasn't the same on the new versus the old and it was actually turned 120 degrees so it looked the same. And it doesn't take that much force unlike other connectors to insert it incorrectly.
Yep, that's it. Feel like a fool but at least all is good, ZPC was done and i'm certain all my other connectors are clean and firmly pressed in and fuses are good because I chased every single one that could potentially be causing a fault.
I just replaced my rear rotors/calipers (2007 LX) after having one seize up and make a mess while pulling out of my neighborhood. Next step is to bleed the brakes and I'm wondering is you guys use Toyota dot 3 fluid or something off the shelf. (I read here earlier @2001LC flushed 2 gallons while working on a problem rig. Thats a ton, especially at Mr Toyota prices.)
How much fluid should I have on hand to do a total flush? I bought two pints when I picked up the calipers but now that I'm thinking about it that doesn't seem nearly enough especially when I'm thinking about how much leaked out on the road. Thanks.
How much fluid should I have on hand to do a total flush? I bought two pints when I picked up the calipers but now that I'm thinking about it that doesn't seem nearly enough especially when I'm thinking about how much leaked out on the road. Thanks.
trdcorolla
SILVER Star
I wenth through almost 1 gallon of Prestone DOT3 when I flushed my brakes a few months ago. I went through a few techstream abs bleeds on each caliper.
Thank you,
I did test the fluid level to 40 pumps and it's just below the max and is 35 seconds with key on for the motor pump. What is odd is that my fluid level seems to rise after sitting for a day or so compared to when I checked right after the light comes on. I am just going to replace the whole unit, Looks like I can pick one up for around 1300 bucks. Hopefully it last another 20+ years and I don't have to deal with it. Anyone have a part number for a 99 lx 470 complete unit with pump and accumulator? I seem to get mixed answers on what a "complete" unit is.
Thank you again
It depends if you’d like to get the system all clean or just replace the fluid and call it a day. My old fluid was factory fill ~23 years with 105k miles. I’m light on brakes and pressure was still good on old fluid.
When I did flush my brakes this year I got a little more than 12 x 12Oz Toyota DOT3 from a local dealership parts store in order to get the reservoir to turn clear gold.
Rep said I needed 3x 12Oz max. But that’s for a corolla/sienna/camry type of vehicle with very little reserve braking power. But the Land Cruiser’s braking system has a pretty high system capacity.
Flushing with cheaper DOT3 fluid until the fluid gets clear gold and dilute that with Toyota DOT3 is an option too.
Using techstream ABS bleed + manual bleed is going to save you more fluid than all manual. Getting the fluid low before refilling (while making sure the pump doesn't take in air) is going to save fluid too.ABS Techstream + manual bleed pretty effective in getting a lot of air out of the lines. I gained probably 10-20% pedal feel on new brake fluid. If you're trying to correct something like a rust problem in the hard lines or suspended ultra-fine dark particles out, getting closer to a gallon might be a better choice.
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Look around some Lexus dealers. I did search just for giggles and found some that would ship for free with not tax around $1200.
Lexus parts 17.76% off until July 5th
I went to my favorite Lexus parts website to price a few "LX" only items and saw this promotion. This is only for dealers participating in the "Simple Part" sponsored parts e-commerce sites, you can put your part # and zip code into Shop Lexus Parts and Accessories Online -...
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The level will come up in reservoir as fluid pressure bleeds back off from accumulator. This starts as soon as pump turns off. It's why will see level change (go up) overnight or just hours after parked.
What most everyone and every shop misses, during a flush. Is flushing the accumulator! It's why I use more fluid in a flush than most. I use 3 bottle of Toyota brake fluid, about 1/2 bottle at a time, just to flush accumulator.
How?
Easy!
Once I've reservoir drained down (key on, brake pedal held down, open rear bleeder) to very near the bottom. Bleeder closed, key off, pump brake pedal 40 times. Level raises to about 2" from bottom of reservoir, as accumulator evacuates fluid into it by pumping brake pedal. I than add fresh brake fluid, to old in reservoir, doubling level to about 4". So I've a 50/50 mix of old and new in reservoir. Key ON, booster motor charges the accumulator again, drawing down the now with the 50/50 mix. Hold down brake pedal, IG key on, open rear bleeder and flush reservoir to very near the bottom again. Repeat 5 more times.
Than fill reservoir, and don't not let level below minimum as you bleed all four.
What most everyone and every shop misses, during a flush. Is flushing the accumulator! It's why I use more fluid in a flush than most. I use 3 bottle of Toyota brake fluid, about 1/2 bottle at a time, just to flush accumulator.
How?
Easy!
Once I've reservoir drained down (key on, brake pedal held down, open rear bleeder) to very near the bottom. Bleeder closed, key off, pump brake pedal 40 times. Level raises to about 2" from bottom of reservoir, as accumulator evacuates fluid into it by pumping brake pedal. I than add fresh brake fluid, to old in reservoir, doubling level to about 4". So I've a 50/50 mix of old and new in reservoir. Key ON, booster motor charges the accumulator again, drawing down the now with the 50/50 mix. Hold down brake pedal, IG key on, open rear bleeder and flush reservoir to very near the bottom again. Repeat 5 more times.
Than fill reservoir, and don't not let level below minimum as you bleed all four.
Thanks for that link, I ordered one up for 1220 shipped. Called my local to see if they would be close and they wanted 1750 and told him what I could find it for online to see if he would match but lowest he would go it 1575.Look around some Lexus dealers. I did search just for giggles and found some that would ship for free with not tax around $1200.
Lexus parts 17.76% off until July 5th
I went to my favorite Lexus parts website to price a few "LX" only items and saw this promotion. This is only for dealers participating in the "Simple Part" sponsored parts e-commerce sites, you can put your part # and zip code into Shop Lexus Parts and Accessories Online -...
Hopefully now it actually ships within a reasonable timeframe.
Thanks for that info.
I ordered up a complete unit, how many bottles do you think I'll need for the install?
Running too much means the pump taking too long to pressure up (>20sec) or running too often (losing pressure in the system). If the pump is weak it can cause either one so replacing the pump may or may not help. If it doesn't the next easiest fix is the accumulator though most people rebuild the master. if you change the pump and rebuild the master and you get total brake failure it's the accumulator. But hey pump like hell because if the other two are good you can regain stopping power without fluid in the reservoir. Have fun!
5
No need to flush accumulator with new master & booster assy.
