Complete Brake Failure

I've locked up the 2016 brakes while off roading a few times. The pedal pulses a little and the car-with-wavy-lines-under-it lights flashes.

 

With both feet on the brake peddle any chance one foot was touching the gas peddle. Maybe even just alittle bit. I have big feet. shit happens. And you said the truck as accelerating

 

There was no pulse. The peddle was dead and to the floor. This might be ABS related but it was not the normal ABS response that I had.

 

Positive. I don't touch the gas as I idle into position. Right foot was brake only. Left foot came into play when peddle went to the floor. I wish it was just me being an idiot.

 

IMO it can't hurt to look. I agree with not topping it if it is low

 

I just had a Chevy sonic in for a similar complaint. Had a faulty master cylinder. would make pressure one time, and go straight to the floor another time. I didn't open it up since GM wanted it back.

 

I remember in a 2007 4Runner, there was a procedure to test the accumulator that pressurizes the brake system. Pumping the brake pedal 10+ times, the system will beep and the pedal travels all the way to the floor. Might be the same for the 3rd gens. I do remember that when that pump/accumulator breaks that it was like a $1,500 part.

 

I'm leaving shortly to go to the dealer. At this point I still don't know what to do. Right now I am thinking of taking it right to a parking lot and trying to duplicate it myself. Or try in their parking lot so if something happens I can just honk the horn while holding the brake down to prove it and so they can test right there. I am still nervous about trusting the truck on the road. I am meeting with the GM about the 2015 DCSB OR but I could have bought that to begin with. I like the interior and features of the 16. If I switch I know I will be safe in a trusted platform I just feel I would be unhappy with the 15.

 

Well well well. I will have to ask a tech tonight if this is still the test procedure. I could have pumped it ten times. I take it slow so I don't hit anything. I don't think you know how happy this answer could have made me!

 

Good luck man, keep us posted

 

As a tech, I would replace the ABS unit and master cylinder. Parts are cheaper than a life. Let toyota eat the cost.

 

There should be an audible beeping when this happens. I recently changed rotors and pads on our 2010 4Runner and did this procedure to check the accumulator/pump and sure enough it beeped and pedal to floor.

 

one second, i'll go try it

 

If you have another vehicle to use I would try and leave the truck with them for a few days. Have one of the techs take it home a few nights. Or if they have you in a rental for a day or two

 

Engine running, shifter on park, and parking brakes engaged. Haven't tried it on the truck as I had no reason to. I do know that the sport and off-road have different system due to A-trac.

 

i just tried it engine off and engine on, it didn't do anything.

 

Weird problem for sure OP. Hope you get it figured out. If I remember correctly there was a thread when the '16s were first released that a guy was off roading, crawling down a steep incline and when he hit his brakes the pedal went to the floor and he had to pull his parking brake.

 

Are you 4x4? Engine off will just stiffen the pedal as the brake booster/pump is off.

 

yes 4x4 truck, but was in 2wd

 

Just wondering as only 4x4 got the A-trac. I haven't looked under the hood of the 3rd gens but it was just a theory as that is the only reason I know the pedal goes to the floor but that was on a 4runner. I was just assuming the brakes are similar for the tacos.