Weird noise, almost like a smaller window motor???

[NJshadow93]

I just recently started noticing that when I start the truck I hear what sounds like a smaller version of a window motor. It is a very low noise and sometimes you don't realize you're hearing it until it stops. It is not just upon start up, I also hear it start and stop when I am driving or parked. The best way I can describe it is that a miniature power window is stuck. I hear it right in front of the driver. Has anyone else experienced and/or looked for help about this?

 

[Doozi]

Sounds like you are hearing the electric brake booster... perfectly normal.

 

[nickson127]

Is it the same sound you get when the DAC is activated and the system kicks in?

 

[NJshadow93]

Is it the same sound you get when the DAC is activated and the system kicks in?

I've only used DAC once and I just remember a lot of beeping noises, grinding noises, and I don't really remember what else. But the sound I am describing is a very low noise and I didn't start to notice it until I sent my stereo out to get fixed and had to deal with quiet rides. And the noise comes and goes, and I don't really notice a pattern with how often it happens.

 

[NJshadow93]

Sounds like you are hearing the electric brake booster... perfectly normal.

Hmm..what is the electric brake booster? And keep in mind the noise comes and goes, I am not sure how often or for how long. I think it always happens when I first start the truck for a few seconds then stops. Then it starts up again a little while later and stops.

 

[nickson127]

I guess my DAC thing wasn't a good example, lol.

I've noticed some sound with my rig too. Not sure if it's the same sound but usually from start up and go. To me it's kinda like an electrical springy sound that come from the foot brake area.

 

[utobiaus]

If it's right at startup try this...Flip the key to on but not start. If you hear it then it's the fuel pump.

 

[Doozi]

Hmm..what is the electric brake booster? And keep in mind the noise comes and goes, I am not sure how often or for how long. I think it always happens when I first start the truck for a few seconds then stops. Then it starts up again a little while later and stops.

We have an electric brake booster that keeps brake vacuum constant. It usually runs when you start the vehicle and then it comes on periodically to maintain vacuum pressure whenever it needs to... it's not constant. Someone on here mentioned it a few months back... I think it might be called the accumulator pump or something like that. I'm searching for more info.

 

[NJshadow93]

We have an electric brake booster that keeps brake vacuum constant. It usually runs when you start the vehicle and then it comes on periodically to maintain vacuum pressure whenever it needs to... it's not constant. Someone on here mentioned it a few months back... I think it might be called the accumulator pump or something like that. I'm searching for more info.

Oh ok. I think i noticed that i hear it when i step on the brake to slow down. I'm not sure if this is consistent but yesterday I noticed it nearly every time, if not every time, I pressed the brake to slow down. Again, I don't know whether or not this is a coincidence but I think that's what I noticed yesterday.

 

[Maritimer]

Sit and pump the brake and see if it does it. My 3rd makes a wind-up toy sound every now and then, and I narrowed it down to something brake related this way.

 

[JSimmons]

Fuel pump?

 

[jbird27]

Mine does this as well. I'm fairly certain it is normal. I believe its a vacuum pump (brake booster) for power brakes even if the engine isn't running. I can turn the key to the on position (without starting) and still hear thee noise...

 

[FRT]

Pretty sure Doozie and Jbird are on point with this concerning the brake pump (booster/accumulator/vacuum). I've got the same noise and occurs about the same times mentioned. I only first noticed it after I swapped my front calipers... Think I was just super paranoid concerning any noises for a while after that. I don't really notice it anymore unless I'm listening for it.

 

[xlaxx]

I hear the sound too, on ACC or start-up. Figured it was something related to braking as well.

I do hear a momentary 'click' sound (NOT door lock) when I place the truck in DRIVE and go forward about 10-15 feet. It is a very light click, like something brake-related. I am not sure what that might be either?

 

[MICA4R]

We have an electric brake booster that keeps brake vacuum constant. It usually runs when you start the vehicle and then it comes on periodically to maintain vacuum pressure whenever it needs to... it's not constant. Someone on here mentioned it a few months back... I think it might be called the accumulator pump or something like that. I'm searching for more info.

x2 Doozi.

annoying stuff that toyota does all in the name of safety.

anyways, the master cylinder is pre-pressurized in the event that you have to suddenly brake you get a "boost"

when you are normally driving the vacuum from the engine keeps the master cylinder pressurized until you come to a stop and "use up" the vacuum pressure so the little electric motor kicks in.

annoying sound. just turn up your radio it fixes the issue.

 

[NJshadow93]

Ok thanks for the replies. I kinda figured it was a normal sound but wanted to make sure. It kinda sucks right now my Kenwood stereo is out for repair right now so I'm into the second week without it. At least I get to hear all the little noises now. Also I'm sure this isn't a big deal but my V8 makes a noise that kind of sounds like a police siren in the distance. Again, seems normal but if anyone's got something to say about it while we are in the noise topic. I hear it on regular acceleration.

 

[Snesley Wipes]

x2 Doozi.

annoying stuff that toyota does all in the name of safety.

anyways, the master cylinder is pre-pressurized in the event that you have to suddenly brake you get a "boost"

when you are normally driving the vacuum from the engine keeps the master cylinder pressurized until you come to a stop and "use up" the vacuum pressure so the little electric motor kicks in.

annoying sound. just turn up your radio it fixes the issue.

All this but from what I understand it is to keep the brakes working in the event of a stall. If you roll your car while it is off you'll notice your brakes will always work.

 

[sonerick]

Anyone notice that their headlights flicker a little bit when the brake booster/vacuum pump/accumulator/whatever its called kicks in? Mine does it, and its kinda annoying at night.

I was thinking that bleeding the master cylinder might help... anyone have any success doing this?

 

[NJshadow93]

Anyone notice that their headlights flicker a little bit when the brake booster/vacuum pump/accumulator/whatever its called kicks in? Mine does it, and its kinda annoying at night.

I was thinking that bleeding the master cylinder might help... anyone have any success doing this?

i looked for it last night, and no my headlights stay the same the entire time

 

[jheight84]

I have been dealing with the same ting. No luck on bleeding the master cylinder so far. I actually started a post asking if anyone had any luck, yesterday. The service manual has some steps that "might" work but did not for me...