Brake Failure!!!!

Same with electronics. They don't generally "just fail." I could be mistaken but I believe the electronic portions are related to the ABS, crawl control, and the electronic brake booster which is why the brakes in the OR/Pro feel so firm. But a complete failure of those parts should not leave you without the ability to stop. Much like cutting a single brake line doesn't result in complete brake failure.

 

This is a very big clue. This would point me right at the brake booster, and in your (understandable) panic, you may have just not pressed hard enough. That's what I'm thinking.

 

My money is on the booster.

 

Does that apply to the OR?

 

It does not.

Jeff

 

So basically not something that most can do at home.

 

Not exactly but you can do the basics. Key off, pump the pedal 20 times until the stroke is longer and pedal softer, key on, electronic booster pump should run to recharge which will also firm up the pedal. The pump noise is pretty obvious, especially with the hood open.

 

agreed. Think he kind of did that already, but without the excess pumping to bleed off accumulator. Confirming power to the pump would be a good place to start if it's accessible.

 

So I actually had the opposite happen yesterday. Was on a gravel road and did a little slide in the gravel and came to a stop. When I tried driving again the truck wouldn't move for about 45 seconds. The brakes had just locked up and wouldn't let the truck move. I've never had anything like that happen in any vehicle. After my incident and reading yours, these brakes are confusing the hell outta me.

 

Master cylinder seal failure?

 

Are you sure, what are you using to read the codes? Remember the MIL light should just be for emission related codes, so the MIL light might not be on. You usually don’t get the dashboard Christmas tree lights without some codes being logged, you just might need to use something like tech stream to pull them, rather than generic ODBII reader like Scanguage.

 

I am not a sparky. Mechanical stuff speaks to me.

I know there was a Recall on some vacuum assisted ones. The electrical ones are their own monster.

 

The electrical ones are their own monster.[/QUOTE]
I was in a pickles going down Cabbage pass in loaded Prius with e/booster (engine off most of the time). One of gear jammers was having a hard time going down. No effort what so ever.

 

sounds like it didn't like going backwards while locked in 4lo. might just need to clear a code. weird electronic nannies so you don't break something.

 

Pretty sure there was a recall on brake master cylinders on some 18 and 19s

 

My son and his wife drive a 2007 4-Runner. They had something similar happen and the dealership swore it was the master cylinder. They had a choice from the dealer, a used replacement with a 90 day guarantee for twelve hundred bucks or a reman for a lot more with a year warranty.
They chose the MC from a wrecking yard. On the fifty mile drive from the dealership to their house the used MC went out. So they had to wait again for another shipped MC. The next replacement went out on the way home. So that makes three including the original. The next, the next, and the next all went out within a week of being installed. Finally my son demanded a reman at their cost, which was about the same as the wrecking yard MCs.

No issues since and it's been a couple of years.

It's pretty freaky when the brakes go out and you can't stop. They are lucky they never crashed. Grandbaby in the car so it was damn well past time for the dealership to perform.

 

Ya got a link to share?

 

No, the OR has a hydroboost (hydraulic boost) system. This uses pressurized fluid to amplify the braking force you apply at the pedal. There is an electric motor, pump, and accumulator as part of this hydraulic boost system.

 

When I was struggling with an issue with my parking brake cables after I lifted my truck, for a while thought I had an issue with the brake electronics (turns out I didn’t). During troubleshooting I pulled the fuse that feeds the ABS, and although the TRD Off-road has a hydraulic system, with that fuse pulled, and the electronic brake booster off, it felt like I had no brakes at all. Driving around without the electronic booster active is no bueno. If you haven’t already, double check that fuse is not blown.

Did you add any aftermarket wiring to your truck?

Have rodents chewed your wiring harness?