2002 4Runner Brake Accumulator Noise...

[polvadis]

Hello,

I'm new here, spent the last week reading all 4Runner forums to try to answer this question that is bugging me about my brake accumulator... so here it is:

I just bought my 2002 4Runner couple months ago, and about a month ago i started noticing a funny sound from under the hood.
It turns out the noise comes from a brake accumulator (i've been told thats what it's called; a cylinder shaped part next to the brake fluid container with "Nitrogen..." written on it.)
Every few brake pumps that cylinder will start buzzing and few seconds later a loud relay on the other side of the engine compartment will turn it off.

Is that normal

I've been told that it is; that the cylinder, or accumolator, keeps pressure on the entire brake system and after few pumps of the pedal it kicks in to regenerate the pressure.
But I just don't think it was ever this loud, or maybe I just started noticing it.

On the attached photo you can see what i'm talking about. The right arrow is the buzzing accumulator, on the left is the loud relay that starts it and shuts it off.



Anyone out there have a 2002 4Runner that could check this for me? See if you get the same thing?

I tried comparing this to my family's Toyotas ('03 Tacoma and '98 4Runner), but they both have a completely different system, which is weird that a newer Tacoma has an older 4Runner's brake system...

Thank you for any info.
-polvadis(at)yahoo.com

 

[02sport]

if it's like a hiss then a pop(click) it's normal. my 02 sport has done it since day one, and my previous 02 sr5 did it too. was also told it was the brake system "recharging"

 

[polvadis]

if it's like a hiss then a pop(click) it's normal.

yeah, nailed it right there.
a hiss and a pop, at least once every other stop light, or more often if the brake pedal is pressed more.

i think i just started noticing it now since i've been driving without a radio for a couple weeks. but now that's all i listen for. guess with time i'll ignore it again.

thank you for the info. i'm really glad it's not just me imagining things, my parents both think i'm crazy cause i made them drive my car and they can't hear anything...

 

[THUNDR CLOUD]

Same here with me. Kinda reminds me of the radio Ant. going up or down only shorter in duration and not as loud followed by a pop. I notice mine more in the mornings but I think it's because I dont have the radio as loud in the AM. Seems like I notice it more when it's cold outside also.

Anyway sounds like were going to have to live with it. Not a show stopper for me...still the best vehicle I've ever owned!