Brake Pedal Buzz / Vibration When Stopped

You can thank that super awesome crawl control feature for your buzzy brake pedal...

Annoyed me for awhile when I first got my truck too

 

I can't believe that nobody has chimed in with an answer for this yet. I know what it is because it's been that way in 4Runners for a long time. My 04 4Runner does it. Maybe it's a feature that's new to the Tacoma lineup even though it's been in the 4Runners and FJ's (I'm pretty sure) for years?

It's a brake booster. These trucks don't have normal master cylinders. They have motors attached to them and they build a reserve of pressure so that the truck can apply the brakes on its own either to help you in an emergency stop or to keep one of the wheels from spinning excessively.

What your feeling is the pump building up pressure because a sensor has detected that the pressure has decreased. That reserve pressure is used any time you brake so the motor will kick on intermittently as you drive to replenish the pressure.

The only bad part about the system is that it's ridiculously expensive to fix. When it fails it'll cost you about $2500 to replace. Toyota only sells them as complete units. Fortunately they're pretty durable. Most older 4Runners are still on the original unit at 300k miles.

It's not just for the crawl control. I have a manual transmission so I don't have crawl control but I still have the same brake booster pump.

 

Thank you for that response. I've noticed that the pressure builds upon startup which felt odd to me at first.

Is it normal to feel a kind of pulse/click/clunk in the pedal under normal braking? Almost the sensation of a single ABS pulse.

I get this when a moderate braking pressure is applied. If I hit the brake with the same pressure shortly after, I do not feel the sensation. However, I drive for another 10-15 seconds and apply the same moderate pressure and I feel the little pulse again.

Almost feels like the pedal is slipping on a rubber bump stop but this does not occur when the engine is off.

 

I can't say that I'm familiar with that sensation. I'm sorry.

With mine, both the 4Runner and Tacoma, the brake feels entirely normal except for the occasional high frequency, low amplitude vibration when the pump kicks on.

 

This is a much better explanation than the dealer saying "that's normal, there is nothing wrong." My 2017 Pro does this light vibrating of the brake pedal randomly. I have yet to figure out a pattern for this behavior, but if it is normal, it gives no reason to worry.

 

I see this forum is full of useless trolls

 

Yeah
Mine does it too. I consider it a "characteristic"

 

Thansk for the response! Seems logical.

 

Brand new 2018 Tacoma Off Road owner right here. I experience this situation too.

 

It's normal. Mine does it.

 

Thanks @iDrew

 

Brand new 2019 TRD OR 4x4. Feel slight buzz when first pressing on brake pedal then stops. Only at slow speed. Push again maybe buzz maybe not. Is this just the electric braking system on the ORs? This happens even when in park.

 

slight buzz when pressing on brake pedal at stop (in park) or slow speed>? is this just electric braking system on OR?

 

Is normal. My 18 OR does it also. And is only on the OFF-ROAD.