whirr/humming sound
 

Just got my '99 7.3 the other day. It's making a slight whirring sound that I believe is in conjunction with steering. Would that possibly be the master cylinder?

Also, the brake pedal kind of makes the same type of sound if I'm already braked, but then push the pedal down further. There's a vibration in the pedal when you do this.

Start the truck and leave it in park to see what causes the noise.

If it makes it when you turn the steering wheel, it is likely in your power steering pump - check the fluid level, look for a leaky supply hose or bad seal.

There should be no noise when you push the brake pedal to the floor.

If both of these check out, then you get to put it in drive and get up to 10mph max. Any noise at cruising speed, travelling in a straight line on a flat road? If so, it could be a plethora of things... get more info.

If no noise, try the steering and brakes again to find the problem. If the whirring only occurs when you are mashing the gas, you're likely hearing the turbo spool up - in which case, enjoy the sound of a 7500lb truck reaching terminal velocity. Hope it helps. :-fire

Thanks for telling me a process to use. I'm gonna go check it out right now...

The noise when turning sounds like the p/s pump. The vibration in the brake pedal/steering wheel sounds like your rotors are warped. Front brake job and turning the rotors will fix that. Hope this helps.

Here's the report: The brakes and power steering are making the exact same sound. This is with the truck in 'park'.

Start turning the wheel and 'rrrrrRRRRRRRrrrrrr'.

Mash the brake pedal and 'rrrrrrrRRRRRRrrrrrrr'.

I had a friend verify that with me this morning. He agreed it was the same sound.

Puzzling.

(by the way, in response to the last poster, there really isn't a vibration in the steering or brakes. The slight vibration in the brakes feels more hydraulic or something and it occurs with the vehicle in Park.)

Sounds like your about to buy a powersteering pump.It also runs the brakes.

SWEET!!! I've got so much $$$$ to throw around lately. :)

I just checked with my mechanic and he said they could replace the power steering pump for $160 parts & labor. Does that sound about right?

throw some over here....i need new tires (Coopers would be delightful), injector O-rings, maybe a TS performance 6 pos flip chip if you got some change. :-X22