TRD Off Road Brake Pedal Hiss

2015 TRD Off Road 4x4

Whenever I press the brake pedal there is a quiet squeak/hiss. Very noticable when the radio is off in quiet traffic.

Dealer seems to think it is normal and has something to do with some special braking system the TRD off road trucks have. I'm not so sure- can anyone else verify this or had similar experience?

No leaks, strange performance or anything else. Just the noise

 

My 4runner 4x4 with the same brake system does the same hiss. Normal as far as I know.

 

Special braking system? That's new to me, but my '09 TRD makes the same noise.

 

The 4x4 models have the electric boosted brakes. Picture below:

 

If your master cylinder lookslooks like the picture I posted you have the electronic brake system. The hissing or pulsating is normal but should not do itit all the time. The arrow is pointing to the actuator that vibrates.

 

Jinx lol

 

Yep...

 

So that's what the Hell that thing is! I always wondered but was too embarrassed to take a picture and ask, lol.

 

09+ TRD OR 4x4 models get the MUCH better all in one electric boosted master cylinder / traction control / abs unit. The hiss is a byproduct of its design and a lil vibration in the pedal sometimes is felt due to the electric pump keeping pressure in the accumulator.

 

I have an 05 SR5 and I have it in my truck, it was an option since then I presume. I would rather have the regular booster, bleeding the brakes in this system is a pain in the a$$.

 

Yup. 05-08 has the option (tho not often bought) of vsc package which included the electric boosted master

Bleeding brakes on these systems is WAY easy as it pumps fluid for you!

 

Yep, normal, mine does it too. 2014 TRD OR.

 

If you can, please send me a PM with directions. Everything I read was confusing...

 

Should be able to do it pretty easy. Get a piece of wood that goes between the brake pedal and front seat and use the front seat adjuster to push the brake pedal down a bit. Turn the truck to on (engine does not need to be running).

Then you should be able to crack a bleeder, and because the pedal is depressed with the truck on the electric pump will push fluid continuously until pressure is built back up (when you close the bleeder). Just watch the reservoir level!

 

Thanks, wanted to do it with stock bleeders. When the time comes I will try this

 

Ok so yes.. finally someone that doesn't say it's the "booster". Our Off-road models have the hydraulic electro-assist brake system.

Mine is whistling, extremely loud.. Just started this weekend. Something isn't right, but the brakes still work. Does anyone with more knowledge of this setup have any ideas for me? I'm going to take my wheel off and check the pads, shims, etc, but I'm very confident the sound is coming from the brake system pictured above.

 

Do you have a video maybe of what it sounds like? Would be easier to take it from there...