Brake Booster failure....well almost, scary! (1 Viewer)

[GRunner]

Totally epic...

Drove to dinner with parents in the LX. When got out from dinner the truck started with the ABS, BRAKE, VSC, ATAC lights came on with the dreaded long beep. Tried to start it again after removing battery same thing. I tried to drive the truck out of the parking lot but I lost braking power COMPLETELY before I even got to the first stop sign. All stop!

So I pulled over and called for a AAA tow to the Lexus dealer I'm familiar with. The next morning I got a call from the service adviser saying the brake booster needs replacement and will cost about $3000+ tax. OMG! My heart sunk!

About 30 minutes later, I got another call from him telling me the truck is fine now and there wasn't any problem after the tech drove it and resetting all the codes. I picked up the truck and came out with a $0 balance.

So I am just wondering now... what is the chances it will happen again? Should I be concern now since this started happening? What can I do as a preventive maintenance if I want to keep the truck for another 5-10 years?

 

[OregonLC]

Surprised they let you leave. Pretty huge liability if they didn't clearly know the cause. If it was something simple and obvious (like a loose plug) then ok, but otherwise I think I'd press in a little further to understand the cause, especially if wife/kids were going to be traveling in it.

The fact that you had zero braking and not just a stuff pedal leads me to believe that either there was some debris that caused the master cylinder piston to temporarily lose its seal or one of the ABS valves stuck open.

 

[GRunner]

when i opened the hood to unhook the battery I saw that the brake fluid was higher than the "Max" mark by about 1cm. but after i took it home and rechecked it was now back at the "Max" line. i am suspecting something gone wrong with a brake fluid change or like you said there was debris in the brake fluid reservoir.

where should i start to look? or should i really replace the master cylinder at a non-Lexus shop just to be safe?

 

[OregonLC]

when i opened the hood to unhook the battery I saw that the brake fluid was higher than the "Max" mark by about 1cm. but after i took it home and rechecked it was now back at the "Max" line. i am suspecting something gone wrong with a brake fluid change or like you said there was debris in the brake fluid reservoir.

where should i start to look? or should i really replace the master cylinder at a non-Lexus shop just to be safe?

I'd start by relaying your concern to the dealer. There is a rebuild hit for the MC but without knowing the failure mode it would be hard guess. The MC kit is, AFAIK, the only rebuild option. A whole MC assembly is around $1800 in parts.

 

[GRunner]

Well it happened again. Luckily it happened very close to home and I was able to limp back to the garage.

 

[GRunner]

Started a case with Lexus Cust Satisfaction. They are not going to offer me anything saying the car is old and has 150k miles on it. So I told them I feel this is a 6000 pounds ticking time bomb waiting to happen and she said I have to ask my service adviser about it as they have no idea about mechanical issue with the vehicle.

So the bottom line is, should I fix it? Dealer quoted $3300 + tax! One year warranty on the part... How many more miles can I get out of it?

Also I've looked at the 200 series too and it seems like they have the same integrated design also. Which is really scary as if there is a blown fuse for that part then the whole vehicle will lose the braking power completely. For such a large vehicle I think it is an unnecessarily integrated and expensive part.

 

[uHu]

When the booster is fully charged, you have enough pressure accumulated for 20 full stops, even if the booster pump stops working, and that's when the warning light and buzzer comes on.
So, as long as you stop immediately, you should be OK.

Loosing the booster really feels like a complete loss of brakes. There is only a small braking force at the front wheels with a lot of heavy pedal work. The rear brakes are completely booster driven.

The booster pump is run by an electric motor, with brushes, and it will fail sooner or later.

Edit:
20 stops is incorrect. If the booster accumulator is fully charged, there is pressure for pressing the pedal 20 times, standing still. In practical terms you have enough pressure for 2, two, full stops, maximum, when the alarm comes on, as long as the problem is only the booster motor.

 

[Tapage]

could be the brake booster check valve .. ( if it have one ... )

 

[2003lx470]

Last week, I was talking to a Lexus mechanic about the breaks. How can you tell the difference between MC failure and Break Booster failure?

This is what he told me:

MC failure: when you press the break pedal, pedal goes all the way to the floor with no breaks.

Break Booster Failure: when you press the break pedal, it is stiff and will not move.

Hope this help.

 

[packetstormin]

Hmm maybe I should budget for one of these as well. This thread has instilled fear in my Hundy lovin heart.

 

[FXR UPR]

Sound like the accumulator motor is on its way out. I had same issues with my 99. You must replace the accumulator assembly. My cost was $2000 and I'm a Lexus employee. What codes did you have?

sent with smoke signals

 

[FXR UPR]

Search " C1256 my findings" thread I started. It has pics and part numbers

sent with smoke signals

 

[GRunner]

Yes 2003LX470. I think mine feels like: "MC failure: when you press the break pedal, pedal goes all the way to the floor with no breaks."

The sad thing is the 200 series seems to have the same integrated design... so can't get away with it even if I upgrade to a newer model.

 

[GRunner]

Well FXR UPR, the adviser at Lexus said they are not going to put it on if I source it myself... I just don't like to get the parts and then find out later it won't fix the problem. Perhaps I will see if a local shop can help me put it in once I get the parts myself?

The sad thing is that now the dealer wants to charge me $160 even if I just have it tow out of their shop and Lexus Customer Service sad they have no control over dealer diagnostic costs because they are individually owned. What kind of bull**** is that?

 

[TXLX100]

Well FXR UPR, the adviser at Lexus said they are not going to put it on if I source it myself... I just don't like to get the parts and then find out later it won't fix the problem. Perhaps I will see if a local shop can help me put it in once I get the parts myself?

The sad thing is that now the dealer wants to charge me $160 even if I just have it tow out of their shop and Lexus Customer Service sad they have no control over dealer diagnostic costs because they are individually owned. What kind of bull**** is that?

What do you mean? The dealer has to get paid for its efforts. I don't know what you do for a living, but I bet you wouldn't give away your services or time for free. If you feel you are that valuable of a customer to the dealer, go talk to the GM and tell him why, maybe he/she will help you.

They won't put the part on because they can't warranty an aftermarket part and the repair. If they install an aftermarket (or used OEM) brake booster and it doesn't fix it, the dealer won't go any further, likely blame it not being fixed on the aftermarket part and you will be stuck. Good luck fixing your truck, sounds like you have a lot of life left in it once you get it fixed.

 

[GRunner]

Hi TXLX100,

Well I totally understand your point and the manufacturer not obligated to fix it due to the age and mileage of the vehicle. I even told the guy who called me (actually the whole thing started with an email to NHTSA) from Lexus customer service that I think it is out of any warranty imaginable but he still insisted me to have it towed back to the dealer for inspection so he could figure something "out of warranty" offer for me. Bear in mind the car was sitting well inside my garage at the time of the call. Even though I wasn't really expecting Lexus would call me at the first place.

So I took up his recommendation and have it towed to the dealer a second time while they diagnose the issue. During this 15 days wait (labor day holiday and stuff) the case manager who called me had quit, and then the new case manager told me there is nothing they can / will do for me.

Well.. I guess I just felt a bit bumped out of luck with this whole ordeal. Should I fix it knowing the brake booster may or will fail again? How many more miles I will get from this truck? Or should I just don't bother fixing it and move on... I researched the new 200 series and they still have the same integrated design.

But like you said, I am leaning more towards just let the dealer fix it and not to think about it for another couple years or when it reach 200k timing belt change to decide whether I should trade it in or not.

Thanks for all your comments!

 

[TXLX100]

It sounds like fixing it is probably a good decision. You would likely be better off fixing it and keeping/trading it then not fixing it and trying to sell it/trade it. I'll keep my fingers crossed this doesn't happen to my LX. I had a similar problem on my Ford, but was able to accurately diagnose it and found a brand new part at 25% of dealer cost.

 

[GRunner]

Thanks for all the encouraging comments. I've decided to fix it with factory parts and the dealer is going to discount the part to $2000 + tax and labor. Will let you guys know how it goes.

Perhaps I should be a bit more "proactive" and get the ahc conversion and rear locker too?

 

[RobRed]

Lexus part premium at work... the toyota version is less costly (list 1500 / street 1130)

http://www.toyomotorparts.com/parts/toyota-47070-60010_pump-assy-brake-boo.html

the 2003 could be more $$$ - the above doesn't include master cylinder which would add 5-600 to parts.

 

[APKhaos]

Just had a similar experience with our Benz ML430. BAS/ETC/ABS lights all set. Braking normal, because in this case it was the ABS pump motor that failed. Its a common problem, and MB replacement ABS module is over $2K.
Turns out that the most common failure is the ABS pump motor, and its a really simple fix:
- pull the motor
- replace the worn out brushes [$12]
- replace the bearings [$18] although the bearings in my 198K mile motor were in nice shape and really didn't need to be replaced.
- Replace the motor - done and done!

Only mentioning this because in cases where the LC brake accumulator motor has failed it would be well worth while to pull the motor, open it and have a look at a simple rebuild. Not sure if this has been done before but it could be a low-cost solution to an expensive problem.