4-Runner Brake Upgrade (Tacoma Calipers) - Pump noise?

[MikeKMitchell]

I finished adding the Tacoma calipers and rotors to my 4Runner. I also replaced the brake fluid one wheel at a time: initial turkey baster to remove most fluid from master cylinder, refill with fresh fluid, bleed one wheel at a time until new clear fluid comes out (continuing to keep master cylinder full).

Brakes work great but sometimes I hear a low level pump sound when the brakes are first applied. Brakes are firm and hard so I'm pretty sure I bled out all the air. The sound goes away after 2-3 seconds and is not heard again unless I've driven for 10 minutes or so without the brakes being applied. What is this pump?

[corax]

do you have ABS? if so, you may need to bleed the ABS pump also . . . if that's the case, read the manual before you start playing around with it (usually has specific procedures for ABS)

[Seanz0rz]

do you have ABS? if so, you may need to bleed the ABS pump also . . . if that's the case, read the manual before you start playing around with it (usually has specific procedures for ABS)


only for vehicles with traction control.

did you upgrade to tundra calipers? what year 4runner do you have, that really makes a difference here.

it could be a normal sound, the traction control system "firming up the pedal" in anticipation of braking.

[MikeKMitchell]

Yes I upgraded to the Tundra calipers and rotors. I have a 2001 4-Runner with Anti-lock Brake System and Traction Control System. Bleeding the ABS called for a Toyota Special Test Equipment so I was hoping that since I did not let the brake fluid reservoir run dry, no air got in "from the top" and it would be OK. Perhaps some air drifted up from the wheels (even though I plugged the line when removed from old calipers.) Where is the ABS pump? I'll listen to it and see if this is the source of the sound. Thanks

[YotaFun]

2001-2002 had a different brake booster set up, my stepdads always has a hiss then tick when we coem to a stop
been like that since day one 2 mile that we had teh truck