Another ABS Brake Failure

[gil12]

Soooo, I drive my 1999 LC with about 175,000 around town - and more importantly, on long interstate trips on the road and on dirt roads (Death Valley, Mojave). Reliability is important - very important. I am also of the mind that brakes are more important than the engine - so what are my options to feel more secure about my stopping power?

From what I understand the options are:
1) replace complete MC/booster for about $2500 parts only.
2) rebuild MC for about $75 parts only.
3) replace booster pump with rebuilt for about $300 parts only.
4) do 2 and 3 above.

Am I off base here? Any suggestions?

Honestly, I'm old enough that I have difficulty understanding the various references to brake parts that my old 57 Peugeot 403 didn't have (which, by the way, had TERRIBLE brakes!) In other words, I say "booster" as if I really understood what it was doing, but I'm afraid I'm mostly just assuming it is boosting pressure - not exactly a giant leap due to it's name, but I am foggy on the actual working of the thing. References to "accumulator", also leave me nodding as if I understood what it was. Which I don't. If someone could direct me to a explanation of the system, I would appreciate it!

Gil

 

[snapaxle]

Same issue on my my2000. Filed the complaint. First time I have ever had a total failure on a braking system, even with rigs topping half a million miles.

 

[spressomon]

For those that haven't been to this related thread: https://forum.ih8mud.com/threads/brake-failure_uzj100-power-brake-booster-repair.720523/


And, from 2005, in FAQ: https://forum.ih8mud.com/threads/no-brakes.31653/

 

[nodaksn3]

Luckily, when mine failed (at around 160,000 miles) I was at a stop sign at Camp Perry, OH picking up an M-1 rifle (bow to Cruiserdan, M-1 collector), so no damage was done, but I then had an unplanned 2-day visit to the quaint city of Maumee, OH while the local dealer fixed the problem for $3600. The difference with the 100 MC and almost all others is the vacuum pump which allows a diesel engine to be installed w/o major changes to the vehicle. I kept my MC with the intent of investigating what exactly failed but have been too lazy to look into it. I'd had the brake system flushed twice because the fluid was really nasty when I bought the truck, but I suspect that the damage had been done and the cylinder seals failed. I will take it apart this winter when I'm back in Phoenix.
Ned

 

[n55luvr]

I don't think complete brake failure is unique to the 100. I just went through this with my Tahoe. Popped brake line = pedal to the floor and no brakes. Happened to me on an exit ramp. Not fun. Oh and I did not have an e-brake either.

What GM did do that I don't see Toyota doing for you guys is GM put out a TSB offering a complete brake line kit (coated lines) for under $300. Granted labor was still high as it was a body off frame job but none the less GM at lease acknowledged the issue (due to corrosion) and offered a reasonable fix.

 

[e9999]

would be interesting to see if one can disconnect the booster with a good MC, and see if adequate braking is still achievable...

 

[buddysharp]

Happened to our 2004 a few months back at ~150K. Total failure on a downhill; wife panic exited into parking lot, downshifting, grabbing e-brake etc. I read that fed law required independent systems front\back to prevent total failure but hey who believes the internet.
Reported to safercar.gov. Took me seriously but said there were relatively few reports on file. Despite good maintenance, failure was in booster pump and supposedly could throw debris around system? Cycling buddy at dealership and shop foreman offered to try to just replace the part but warned if it failed, then I was in for the full unit and would pay for both repairs. Not worth the risk. For you guys saying this is an acceptable failure, wait till it happens to your wife with your kids in the car. Warning alarm and buzzer etc means Toyota knows this is a potential catastrophic failure. Not acceptable.

 

[buddysharp]

would be interesting to see if one can disconnect the booster with a good MC, and see if adequate braking is still achievable...

good question.. I asked it of the shop foreman; his opinion was that braking would be minimal at best without booster. no way to test mine as codes indicated multiple failures

 

[spressomon]

Anyone know if this brake nonsense started with 100-Series or has it been a problem with other Toyota platforms including other Land Cruiser series?

 

[Manhattan]

My '06 failed around 75,000 miles. I did get a warning - some beeps, some dash lights... but then it went away. Next time in the truck, the brakes failed and I was left with maybe 20% braking power. Fortunately, I was going about 5 mph - doing a 3-point turn. Coincidentally, I was doing this turn in front an occupied police car and the brakes failed as I was heading toward his driver's door. Scared both of us.

I did file the incident on that website

 

[e9999]

Scary stuff. I started a poll on this. Please have a look and vote.

 

[SmoothLC]

Please link to the poll @e9999

 

[e9999]

it's in the stickies for the time being

 

[tdkhelene]

After further investigation and testing, my mechanic did confirm that it was the electrical booster pump motor that failed. Also interesting was the fact that when this happened, several electrical relays also failed due to being overworked. I do not believe this has anything to do with poor maintenance. This appears to be due to a defective design. Electrical motors do eventually fail.

I would be interested in knowing if this problem could potentially be linked with a bad MC. Maybe a weak MC could put extra strain on the ABS pump motor... I wouldn't be shocked if there was some sort of link there. That might explain why some rigs have this issue and some don't. If the problem is linked to a leaky / weak MC... It might be an issue that only surfaces if you have failures of other components.

 

[gil12]

It is beginning to seem that regular maintenance should include at 100,000 miles:

1. Rebuilding pump motor
2. Rebuild MC piston

What do the experts think?

Gil

 

[tdkhelene]

Got the parts back today... Ugh... I may have to eat my words about this not being a maintenance issue... taking off the fluid tank, there's a thin layer of grey sludge at the bottom... It drains directly into the M/C valve body... I still need to dig into this a little deeper but I also found some pretty significant corrosion on the ABS motor's electrical connectors. (see photos). I'm wondering now if sludge from poor fluid maintenance drips into the MC and the valving. I'm curious to see how it directly affects the electrical motor though.

Considering I only bought this truck back in February, I don't feel too guilty about being lax on maintenance... (I've already addressed oil, tranny fluid, checked plugs, wires, changed brakes so far...) Obviously, I didn't change the brake fluid... I kinda wonder if that may have extended the life of the ABS pump motor.

Maybe something to add to the Brake Failure Poll: Have you flushed your brake fluid? It'd be interesting to see if there is a correlation to failures and poor fluid maintenance.

 

[gil12]

wow! It is amazing the motor ran at all! Great pictures! I'm closer to either just biting the bullet on the $2000 part, or doing a mc rebuild, motor rebuild, new accumulator. Seeing those contacts makes me think I should do it before I spend money on replacing my weak front diff. (I keep telling myself - "stopping is more important than going") But it is easier to spend money on going than stopping. But that motivation would probably quickly reverse if I suddenly found myself without brakes! Alas, a bit too late though....

Gil

 

[ranma21]

Like to let you guys know that I can supply the New Genuine Brake booster pump 47070-60010 for $1050, about 35% off dealer list price of $1611.14.

 

[tdkhelene]

Shucks... that would have been a nice gift... ranma21. I'll try to look you up next time i have to order something.

 

[Desert100]

47070-60010

Do you have a price for the whole new, genuine Toyota assembly including the master brake cylinder: "Brake Booster With Master Cylinder 98-99 Without VSC"?