No Brakes!!

[marques]

Hello all, new member here, although I have been lurking for a while. My '99 Land Cruiser's brakes suddenly decided to stop working. Pedal goes all the way to the bottom and the result is 5% of the usual braking force. The ABS and BRAKE lights are on and there is an annoying tone that won't shut off.

It did this a few weeks ago, but then magically fixed itself and everything was back to normal again.

From what little I have been able research, looks like it could be the master cylinder, or booster pump, or accumulator. Is there an easy way to know for sure what has failed? Yes, I already know how much these parts cost for this vehicle, which is why I'm trying to figure out exactly what's broken before fixing it.

Is this a DIY job, or is there some specialized computer needed to "code" or "initialize" the system after the repairs?

TIA,

-Luis Marques

[calamaridog]

<It did this a few weeks ago, but then magically fixed itself and everything was back to normal again.>

Scary.

You will need a computer to read this code, Sorry, but I do beleive you will need to see a dealer or someone that speciallizes in toyotas(I would not want just anyone to work on this, personally) that will have the computer to read what is wrong. This is a 4 channel system with a High pressure pump instead of a vaccuum booster. This could be a problem, If it is unsafe to drive, have it towed to some one that can help fix this problem.
later robbie

[BillWms01]

The only thing worse than having a vehicle that now-and-then won't start is having one that now-and-then won't stop! Better get this fixed ASAP!

[Bielecki]

What's the fluid level like in the brake reservoir? Is your current braking capacity just like trying to brake with the engine off while rolling down a hill?


Robbie,

Do you know if any odb2 reader is compatible with specifically the brake computer systems on 100's, or does Toyota have their own prop interface for these type of modules?

[Jukelemon]

B:

Here is an interesting page. Answers a lot of questions.

http://obddiagnostics.com/index.html

[jp213a]

Originally Posted by Bielecki

What's the fluid level like in the brake reservoir? Is your current braking capacity just like trying to brake with the engine off while rolling down a hill?


Robbie,

Do you know if any odb2 reader is compatible with specifically the brake computer systems on 100's, or does Toyota have their own prop interface for these type of modules?

Here's another web site on OBD-II. According to this site and the pins wired in the test socket, the ISO protocol is used in the 00 model year (not PWM or VPW protocol).

http://www.scantool.net/products/index.htm

[marques]

Long story short, the electric motor of the ABS/Booster pump quit working - failed open circuit. With the accumulator empty and no way to pump it back up, the ABS shut down and the system went into "failsafe" mode. Some Toyota engineers must have a really funny concept of a failsafe system because in this case it means a very long and soft pedal with almost no brake force at the wheels.

All is fixed now, $1,400 later + tax. Instead of buying just the pump, I replaced the whole assembly. Call it insurance against some other little thing failing down the road, really requiring replacing the whole assembly. Now I have a spare everything but pump motor. It is a fairly straightforward DIY job. This particular '99 model only had a 3-channel system. It took 3 quarts of brake fluid to finish the job: one to fill the huge reservoir, and two more to really flush and bleed all the air and old fluid out of the system.

I also have some detailed technical information for diagnosing the system. It is a lot easier than it looks at first, once you have a better idea of how it works and how it's all wired.

Regards,

-Luis Marques

[calamaridog]

Good work and good job. $1400? Wow.

[Jim_Chow]

Originally Posted by calamaridog

Good work and good job. $1400? Wow.

The MC/pump assembly on the 100 costs like $1K vs. $130 for the one on the 80 series, which also work on the 4runners and virtually every toyota truck made prior to the 100 series.