Tacoma TRD OR brake pedal click(switch sound)/ faint buzz feel

Howdy folks, hope all are doing well!
I have a 2011 Tacoma TRD Off Road 4x4 double cab with the good ole special, electronic brake booster. I have noticed a feeling over recent months that I would like to ask about to see if anybody might know what is going on...

When I put the truck in reverse, back down a hill, switch the gear into drive, and then release the brake pedal, it feels like there is a faint click or buzz feeling coming only from the pedal itself as I release. I have heard many things that can cause it including things that are normal and even a possible loose bolt on the pedal/the rod in between the master cylinder and the pedal getting itself hung up on something. I am curious to know y'all's thoughts are... No harm or damage is being done as far as I know.

All brakes (front + rear) have been changed and I haven't heard it again since but I'm curious to know what it could be (maybe the booster doing it's thing, or a loose bolt?). Do these boosters have switches in them that could cause it? Seems normal and rarely ever happens...

Thanks everyone!

 

Are you sure it's not the self test it does every key cycle when you get above 5 mph with the brake released?

 

It certainly could be... If you have a moment to spare, would you mind explaining to me what that is? I'm still getting to used to driving a truck because I'm coming from an '03 4runner 2wd, so I have not heard of this yet.
Thanks so much!

 

The hydraulic booster runs a self test every startup once the truck gets above 5 mph where it cycles all the solenoids, it sounds like a quick series of clicks that lasts about a second.

 

That's really interesting... It hasn't happened in a while so is it supposed to occur after every single startup or every so often after however many startups later? You have a great point! It has occurred when I release my foot off of the pedal after I have shifted into D to go forward.

 

Pretty sure mine does it every startup, I've gotten so used to it I don't pay attention to it anymore. It only happens the first time I hit 5 mph.

The other clink noise you may hear when stepping on the brake after changing directions or driving a bit is the front pads shifting due to how they are designed with the 2 pins holding them in place.

If it's something other than those 2 sounds it's probably not normal.

 

I gotcha, it may not be the key cycle then because I don't always notice that but it could be very faint to where I don't notice unless I'm intently looking for it... It only happens as I release my foot off the pedal, but it could be pads shifting inside the caliper, but I'm not sure if that's something one can feel from just the pedal itself. It almost never happens for me so I'm concerned in any way but there is an electronic sound with it so that's why I'm thinking it's something normal having to do with the booster or the connecting rod itself. Maybe its the acculmator filling pressure back up after having been releasing?

Thanks for the help man, I appreciate it! I'd be curious to know what additional thoughts you and others have if more come about

 

I discovered today that it is exactly what you said it was lol... Happens right at 5mph but doesn't happen every single key cycle. Seems to be on a rotation like every other one it does it. I like that it's not every time but I believe it is in fact normal like you stated it to be.

Thanks for the help man, I greatly appreciate it!