99 F350, auto, 4x4. Today my brake pedal started vibrating when I am pressing on it at a stop (traffic light, stop sign, etc). Feels like it's giving my foot a massage. My pads/rotors are almost new and brake fluid is full.

Do I have a problem with my hyrdoboost? What should I look for??

 

Could be an isue anywhere in your belting system, ie pulleys. I would take your belt off to start, make sure idler pulley isnt loosing a bearing, same with tensiononer pulleys. Also your AC clutch could be slipping causing the surging, your power steering pump is what drives brake boost, so if anything in that loop is loose or failing, you wil feel it in the pedal.

 

I recently had exactly the same problem, so I thought I might be able to help. BUT, my problem was that the fluid was low so now I'm kinda stumped. I followed the flush procedure and topped the system with fresh fluid and no more foot massage.

 

I just went threw the same problem you describe.

And like yourself, I have newer pads and rotors.

Mine problem turned out to be that I had a broken belt in my front tire.

I found it when I rotated my tires.

I replaced my tires, and now the truck rides like a new one and no more foot massage when I step on the brake pedal.

Let us now what you find and good luck.

 

im thinking pump try the flush and new fluid thing like kent said if that doesnt do it prolly needs one . is there a similar noise when the steering gets in a bind ?

 

The steering feels and sounds normal...

 

Your power steering pump is what boosts the brake master cylinder. Check the power steering fluid, it should have ATF in it, not power steering fluid.