brake failure

Ah okay, I don't know why I thought your 4Runner was an '03... So the newer style one starts from '05 I guess... could have sworn '06 but I don't see enough 4th gens to compare them as much as I'd like. Wish you the best of luck, if you were local I'd help bleed the system for you after its installed. You're gonna need a TIS Scantool or fabricate your own ABS Jumper Box like we used before the TIS TechStream... Huh, come to think of it, the old SST is just a glorified switch box...

Still wondering about E10PVMT's idea...
 
Here are the pics of mine....again its off an 03 w/112k miles on it....only difference i see from the sketch posted is the computer on the side which i believe is the traction control/abs module...not sure what the module on yours looks like
 

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They have different connector/pin layouts. I haven't had the chance to tear apart a post-'05 unit and see if the valving/holes for the solenoid pack are the same so I am unsure if you can just swap modules. Hence why I said there might be a compatibility issue.
 
This guy is a "no show". I pm'd him as I have a complete MC from my wrecked 03. We emailed back and forth, sent pics, agreed on a price, boxed, ready to ship and ........... Nothing! So either it's fixed or it's some one else's problem now.
 
I have the same problem right now, lost brakes, booster motor is toast. I tore it all apart and found exactly the same problem with the comutator/armature shown in the pics if you scroll through this:

Brake Failure_uzj100 Power Brake booster repair- | IH8MUD Forum

I don't see how every single one of these won't eventually fail the same exact way.

I am looking for a replacement unit, and can't find one less than 1000, even used. 05+ are less $, several can found for 400-500, but of course the one I need is double.
 
Brake Failure

Hello 4runnercolo,no help here on the parts, but if I were you I would file a complant with NHTSA as this is a safety problem that can affect all 4th Gen
4runners.
 
Quite scary. My 06 is approaching 130k on the odo. I've maintained it well, but it seems as though if this unit is going to fail, it will do so based on age. If mine fails, hopefully it is when I'm pulling into my driveway vs the freeway..
 
Hello 4runnercolo,no help here on the parts, but if I were you I would file a complant with NHTSA as this is a safety problem that can affect all 4th Gen
4runners.

I did file a complaint, and have not heard anything back from it.

I ended up finding just the motor/accumulator assembly from a junkyard, off a low mileage wreck. I was hesitant but it was a super clean part, looked almost new. It cost $350 including shipping. I swapped it onto the m/c and it works great. I was even able to drive to a shop without any bleeding where they did the special scan tool bleeding procedure for $100. It took some calls to find an independent shop with the tool. I don't do dealerships.

Total repair cost was under $500, but I am pretty mad at Toyota, and I do not trust these 4th gen 4runners anymore.

Best advice is when you hear that high pitched, constant buzzer and your dash lights up, get ready for no brakes, pull over NOW.
 
Hello 4runnercolo,no help here on the parts, but if I were you I would file a complant with NHTSA as this is a safety problem that can affect all 4th Gen
4runners.

While I don't see an issue in filing a complaint with the NHTSA (and I'd encourage anyone who feels they need to report one to go ahead and do so as it doesn't really hurt anyone to mention your oponion/experience) as if there is a potential issue they will most likely investigate it given enough complaints to warrant it being more than a statistical outlier; it wouldn't hurt to look this post over to better understand the reason why the OP posted what he did.

http://www.toyota-4runner.org/4th-gen-t4rs/122045-complete-brake-failure-thanks-toyota-7.html
 
If you decide to replace the unit i have the unit from my 2003 4runner that i am not using anymore since i am converting to a power steering hydroboost. Let me know if its something you would be interested in

Do you still happen to have this part? I believe that I may be having the same problem with my car.:confused:
 
2005 SR5 V8 with 91,000 Miles.

My wife with my kids inside the car was driving in city traffic when the brake warning (red) indicator lit up on the dash. She did not notice any major difference in braking power the first few stops after this indicator came on.

As she continued additional warning (orange) indicators lit up - I believe they were the ABS, TRAC and VSC - accompanied by a high pitched audible warning.

Then when she later went to depress the brake pedal, it went to the floor with little resistance and fortunately she was not speeding because of traffic.

I checked the car myself yesterday, the brake fluid reservoir is not empty, in fact I don't seems to notice any change in fluid level for like 2 months now. The front and back brake pads are new.


Mechanics here are horrible, I have had two of them checked and they can't figure out what is wrong with the brake.

Yeah that sounds like a complete hydraulic failure of the Hydraboost unit, oddly enough I don't hear/see many full fledged failures like that for the system. Its not a cheap thing to replace unfortunately and the dealer is going to gouge you for it, though it doesn't sound like there are many competent mechanics in your area either.


My brother in law has a 2003 V6 SR5 2wd. He was driving, hit the brake and pedal fell to the floor. Complete loss of brakes. He managed to stop using the e-brake. Had the vehicle towed. Ended up needing to replace the master cylinder.

I guess it happens every once in a blue moon.
 
Brake Failure '04 4 Runner 6 Cylinder

I've been a 4Runner forum stalker for years and I finally had to register to tell my story.

I have a 2004 V6 Toyota 4Runner. I have had it for more than 8 years. It has 220,000 miles on it (I put 150K on myself). I have loved it, loved it, loved it. My niece wanted to buy it from me a couple months ago, but I am not ready to give it up. Good thing!

So, I work from home on Tuesdays to do A/P. I went to the gym in the morning and on the way back home (only a 6 mile trip), my brake alarm went off. I immediately pulled off into a neighborhood pool. Got out, did a visual inspection, checked fluids and looked in the book. Book said to stop vehicle and contact dealership immediately. I'm sorry, but the dealership has not worked on my car, with the exception of recalls, since 100,00 miles when it was still under warranty. The brakes still worked, so I took it home. I called my mechanic and he said he would get me right in. Since they are only 4 miles away, I thought I would be fine driving it there. I was wrong.

The first turn, brakes worked fine. At the next intersection, approaching a stop sign, I lost brakes. The brake pedal would not depress at all. I don't know how, but I managed to hit the emergency brake, throw it into park, turn off the road without hitting anything and lay on the horn all at once. I'm pretty sure a few drivers on the main road may have messed themselves, but nobody came back to check on the lunatic.

I walked home and called a tow truck. While I was waiting for him, I checked out your forum and one more and prepared myself for the impending potential $3,200 cost to repair.

The first garage could diagnose it, but could not get parts. Called the tow guy back and made a deal with him that I would get my baby fixed there if they can indeed get the parts and make the repair if he didn't charge for the 2nd tow. Deal.

They found the same problem as the first mechanic. Hydraulic pump & Accumulator assembly needed and relays. Total bill - $2,224.41 (but no charge for the 2nd tow)

I hope this helps - if your brake alarm goes off consistently, you do not have much time before it is FUBAR. Take care.
 
My bad

There are plenty of competent mechanics in my area. I made the mistake of taking it to my tire guy who does other things too. The only "other things" that I usually let him do are oil changes and alignments. I guess there is a reason for that.

My normal competent mechanic is half way between home and work - 15 miles away - and the tow would have cost me $120 vs. $75 to take it locally. Since I wasn't going in to the office, there was no need to take it that far away. I took it to the place my husband's diesel mechanic recommended.

I still love my 4 Runner, but I have found instances on other forums of this happening. I am disappointed in Toyota that total failure happens so quickly after the warning. Of course, my father has always said that dash lights are idiot lights. If there is something that causes a dash light to come on, it is too late and you forgot to maintain something. I quizzed him this weekend on what I could have done to prevent this and he had no answer.
 
I'm not sure if anything can be done to prevent failure. Changing the brake fluid might help since old fluid absorbs moisture and collects debris over time and can contribute to corrosion. But if you do change the fluid there's some risk of prematurely damaging the system. I changed mine, and now I'm paranoid that the pump is running more than it should. Maybe I'm just paranoid, but it is possible to damage some internal seals while bleeding if you push the pedal past where it normally goes.

When I start is up the pump runs for a few seconds, then rests, then runs for another second. It does this even after it's only been sitting for a short time, like an hour or maybe less. I don't remember it taking more than one cycle at startup. Sometimes when I'm stopped at a light the pump cycles on, and I don't think it used to do that. And sometimes I feel a kind of bump or pop in the pedal either as the pump comes on or as I press the pedal. Some other people have mentioned that, so it may be normal.

So far it seems like only a small number of these systems have failed.

ErinH, it sounds like you got some warning before yours failed, which is good. The problem is it's difficult to want to do a $2000 repair while it still sort of works. Maybe there's a DTC that a shop could read that would have provided some insight about the beeping before you were driving and had actual brake failure.

Maybe, if anyone else experiences the problem, if you get the beeping and you are able to stop safely, then stop, turn the ignition off, pump the brakes 40 times, and turn it back on and see if the brakes still work. Or better yet have it towed to a shop that can read the DTC for the brake system and don't risk driving it any more.

I don't think it's unreasonable for a few of these to fail, and they seem to be designed with a large reserve capacity so you can hopefully still stop once it starts beeping. But I think the cost of replacement is unreasonable.
 
once it starts beeping, it implies that the brake fluid pressure has fallen below an acceptable threshold.........either caused by a broken MC pump assy, or a massive leak in the seals of the mc/abs unit.

in an emergency..stop the car, turn the ignition on and give the mc motor assy a few love taps, this might get it working again..pressuring up the unit and safely get you home.

at least in my case,it worked for 3 more weeks with a few taps here and there
 

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