I know that is not true of Chevy trucks. Someone I know had a passenger in the front seat accidentally hit the auto trans shifter into reverse at highway speeds and it ruined the transmission.
Poll on total brake failure in 100 series (3 Viewers)
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I know that is not true of Chevy trucks. Someone I know had a passenger in the front seat accidentally hit the auto trans shifter into reverse at highway speeds and it ruined the transmission.
The electronic control of the transmission will keep it in a high enough gear to prevent the engine from red-lining, so it won't shift to 1 or 2 at highway speeds, at least until the truck slows down some.
When you get a chance, report this to safercar.gov, as was mentioned earlier in this thread. Multiple failures over a long time may eventually get the NHSTA to open an investigation on the booster pump motor failure in the LC/LX.
How about the local TLCA???
Have the local rep send either to NHSTA or to Toyota Corp.
It sounds like the system does its job of early warning lights and sounds.
Have the local rep send either to NHSTA or to Toyota Corp.
It sounds like the system does its job of early warning lights and sounds.
For those who have had their booster fail. Do you recall any signs or sounds prior to this occurring?
Since i bought the truck (2005) I've heard a buzzing sound every so often when I apply the brake pedal. Even when just sitting with it in Park.
It sounds like the noise from an electric fuel pump. My Indy tells me that it's normal, but I've always worried that it's running a little more than it should... Anyone have a similar sound coming off this unit?
Since i bought the truck (2005) I've heard a buzzing sound every so often when I apply the brake pedal. Even when just sitting with it in Park.
It sounds like the noise from an electric fuel pump. My Indy tells me that it's normal, but I've always worried that it's running a little more than it should... Anyone have a similar sound coming off this unit?
Standard.
well with my tail between my legs, i have to admit that my brake issue was BC of neglect, not Toyota.
Your biggest indication will be a terrible squeal coming from the booster pump area. It will only do it once in awhile but it is a pretty certain eventuality once the squeal starts. Just a normal hum is not something I would worry about and is to be expected. The squeal is significantly loud and disconcerting. I had zero issues with mine until I started letting my vehicle sit for an extended period of time. Ended up replacing the whole assembly and now I am good to go for another quarter million miles or 15 years!
no, 1998 170000 km, to be honest sometimes ABS light comes on, techstream report an pump error I have to check connections soon
Your original posts on the issue (190 and 192 I think) made it seem like the failure was sudden and unexpected. That's more indicative of a MC/pump assembly failure than just worn out pads. I'm not sure how worn pads could cause a sudden failure like you described.
I was thinking the same.
That's what Slee told me so I trust it.
He told me I literally wore the pad down to nothing
He told me I literally wore the pad down to nothing
Thanks for the replies. I was actually asking about the preventative maintenance for the total break failure problem that this poll was constructed around. I've seen failed abs actuator mentioned and Failed ABS booster pump mentioned, but not sure exactly what to tell my mechanic to replace to prevent this problem. I do a lot of road trips in my cruiser at 75+mph in the ozark mountains and a break failure on those roads would be fatal. I've got a 2000 with 176,000 miles on it.
Seemingly most "total brake failures" identified here can be traced back to the electric motor that drives the pump that in turn charges the brake assist accumulator. That electric motor, like all dc motors, will eventually require replacement brushes and commutator re surfacing (or actual replacement if it's too worn and unserviceable) and new bearings at some point based primarily on its duty cycle and operating environment. Now regarding preventative maintence for the motor - not much is on offer directly from Toyota apart from resistance checks and accumulator charge time as per the FSM and most importantly heeding the inbuilt visual/audio warnings for low pressure, excessive current/duration etc. General non invasive testing of small motors like these might include thermal/audio/vibration signatures (compared to a new unit for baseline), insulation testing and current readings but in many applications a small motor like this would just be changed out if it were assessed as a critical item as per your or your industry risk appetite. It sounds like any failure of the brake boost system, regardless of the inbuilt warnings and hopefully residual pressure in the accumulator for emergency stopping, is not acceptable to you so you could have your mechanic:
Fit 47960-60010, the dc motor + hydraulic pump, available for ~$1000 plus installation
Fit 47950-60010, hydraulic accumulator, available for ~$275 plus installation
Fit 47070-60010, dc motor + hydraulic pump + accumulator, available for $1200 plus installation.
*last time a checked p/n and online prices
Send your dc motor to a rebuilder, maybe $150- $250 and 2 weeks down time?
You might want the master cylinder rebuild done too and that kit is ~ $50 or so. But you may well find many mechanics reluctant to open up the MC just from a perceived liability stand point.
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just adding to the brake bleeding discussion, another simpler way to manually bleed is to NOT press the pedal all the way down on an old MC
you can do this by placing a small wooden block under the pedal, or just good control - you have a feel of where the pedal engages, don't go a lot further down than that - engine on OR off
I've been doing it this way after I had to replace about 3 MCs after bleeding, its been quite some time now - no problems at all.
Also - if you flush brake fluid regularly ie. every year or two years - this condition will not occur, the MC will still fail after age, but that would be mostly due to a failed rubber piston ring/seal - easily and cheaply replaced and all will as good as new.
you can do this by placing a small wooden block under the pedal, or just good control - you have a feel of where the pedal engages, don't go a lot further down than that - engine on OR off
I've been doing it this way after I had to replace about 3 MCs after bleeding, its been quite some time now - no problems at all.
Also - if you flush brake fluid regularly ie. every year or two years - this condition will not occur, the MC will still fail after age, but that would be mostly due to a failed rubber piston ring/seal - easily and cheaply replaced and all will as good as new.
Guessing a dealer would charge for at least 2-3 hours for remove/replace & proper ABS bleed then road test.
2001LC
SILVER Star
My two cent.
The poll show very few catastrophic failures.
Lose of pressure due to booster failure does not result in catastrophic failure, brakes will work (poorly) but without assist requiring very heavy pressure on pedal by driver. Park and have towed is best in this case.
Catastrophic failure is most associated with sudden loss of fluid from a brake line rupture or very bad leak (blown seal). This will result in total loss of pressure, means no brakes.
Minor leak (seepage) from bad seal(s) will give early warn signs. i.e. soft pedal & visual clues like unusually low level in reservoir or oil spots on or near brake system component.
----------------Brake lights on>>>>>>>>>>
Two out of three high mileage (215K to 300K) 100 series I purchased last year had brake lights on or warning buzzer sounding.
The first had no brake at all, not even e-brake. A medium size shop told PO ABS & booster need replacing as they where shot...WRONG. The PO was very poor at maintaining, only taking to corner cheapo shop when it needed to be towed in. The actual cause was fluid loss due to leak. Leak was from grind through pads then into piston of caliper. As for e-brakes pad where Bad, thick enough but soft. Additionally the rust around windshield was allowing water to leak getting PS junction box wet. This shorted the system giving false brake warning buzzer sounding while e-brake on.
The second was form wheel speed sensor failure (housing cracked) I feel this was due to improper technique removing wheel speed sensor, that is: prying out. In this case brakes work just fine, except no ABS (1998 LX). Personally I don't like ABS so I was good with this.
Bottom line: These were caused by improper maintenance & servicing and lack of awareness
--------------------Maintenance & Awareness>>>>>>
Pay attention to warning sound (squeal) of pad wear indicators.
Flush system as required, this is even more important once the factory fluid has been flushed out. Moisture build-up in fluid will reduce pressure (lower boiling point) and damage system (corrosion).
Brake lines need inspecting & replaced if showing any damage such as leaks, cracks or bubbles etc.. Line failure is number one cause of total and sudden brake failure.
Visual inspection of firewall in cabin & under the hood around master for leaks along with brake calipers, is very important. Be mindful of brake fluid level, which is also parts of maintenance inspection. A leak at any of these points (seals) is most often associated with a soft pedal, which is an early warning.
Bottom line with proper maintenance & awareness total brake failure is extremely rare.
NOTE: Brake fluid reservoir level will drop as pads wear, so topping off is not necessary or recommended. If reservoir level drops below low line or faster than normal wear would account for, this would indicates a leak.
The poll show very few catastrophic failures.
Lose of pressure due to booster failure does not result in catastrophic failure, brakes will work (poorly) but without assist requiring very heavy pressure on pedal by driver. Park and have towed is best in this case.
Catastrophic failure is most associated with sudden loss of fluid from a brake line rupture or very bad leak (blown seal). This will result in total loss of pressure, means no brakes.
Minor leak (seepage) from bad seal(s) will give early warn signs. i.e. soft pedal & visual clues like unusually low level in reservoir or oil spots on or near brake system component.
----------------Brake lights on>>>>>>>>>>
Two out of three high mileage (215K to 300K) 100 series I purchased last year had brake lights on or warning buzzer sounding.
The first had no brake at all, not even e-brake. A medium size shop told PO ABS & booster need replacing as they where shot...WRONG. The PO was very poor at maintaining, only taking to corner cheapo shop when it needed to be towed in. The actual cause was fluid loss due to leak. Leak was from grind through pads then into piston of caliper. As for e-brakes pad where Bad, thick enough but soft. Additionally the rust around windshield was allowing water to leak getting PS junction box wet. This shorted the system giving false brake warning buzzer sounding while e-brake on.
The second was form wheel speed sensor failure (housing cracked) I feel this was due to improper technique removing wheel speed sensor, that is: prying out. In this case brakes work just fine, except no ABS (1998 LX). Personally I don't like ABS so I was good with this.
Bottom line: These were caused by improper maintenance & servicing and lack of awareness
--------------------Maintenance & Awareness>>>>>>
Pay attention to warning sound (squeal) of pad wear indicators.
Flush system as required, this is even more important once the factory fluid has been flushed out. Moisture build-up in fluid will reduce pressure (lower boiling point) and damage system (corrosion).
Brake lines need inspecting & replaced if showing any damage such as leaks, cracks or bubbles etc.. Line failure is number one cause of total and sudden brake failure.
Visual inspection of firewall in cabin & under the hood around master for leaks along with brake calipers, is very important. Be mindful of brake fluid level, which is also parts of maintenance inspection. A leak at any of these points (seals) is most often associated with a soft pedal, which is an early warning.
Bottom line with proper maintenance & awareness total brake failure is extremely rare.
NOTE: Brake fluid reservoir level will drop as pads wear, so topping off is not necessary or recommended. If reservoir level drops below low line or faster than normal wear would account for, this would indicates a leak.
