freshman

90 4runner auto v6 160k . I just got it,and there is an annoying sound which kicks in when you press the brakes while driving and upon releasing the brake pedal or when running slow (15 miles/hr speed). I can hear it from the driver's side engine bay right where the airbox-air intake is located. btw, there is a drop in K&N in the air box.
help! before i damage my eardrums.

wjwerdna

heres a long shot, but try pressing the brakes and releasing as you are rolling down a hill with the engine off (on a private, non traversed road of course)... or is it definately NOT a brake issue?

freshman

not a brake for sure.

Elton

vaccum leak ?

freshman

probably but why during deccelaration, and which part to check...

86SR522REEFI

If you are shooting down all of the suggestions without checking them then how are we supposed to help you? Im not trying to be a jerk.

UKMyers

Something with the brake booster possibly? I know on my 94 the booster is bolted right to the firewall where you are describing where the noise is.

freshman

yes. i just checked all the vacuum lines accessible but the sound is still there. I just cant check the engine while running...