Ok, I have a 2000 F350 4x4 diesel manual trans.
It just started making a somewhat loud howling noise when I press the brake pedal, and also when the steering wheel is turned.
It has become very hard to steer, as if theres no power steering.
The P/S reservoir is full of fluid, so it wasn't low. The belt is in tact and looks good, so i doubt there is belt slippage.
Does the brake system have anything to do with the P/S system or do I have maybe two issues here?
Any tips on what I should check next?

Thank You!!

 

Yes, the brakes use a HydroBooster. Sounds like you have a PS pump doing bad.

You can try changing the fluid, that may help

 

System Flushing —CII Power Steering Pump
WARNING: Do not mix oil types. Any mixture or any unapproved oil can lead to seal deterioration and leaks. A leak can ultimately cause loss of fluid, which can result in a loss of power steering assist.

Remove the injector driver module (IDM) relay to prevent engine starting.

Loosen the two clamps. Remove the air intake tube.

Disconnect the power steering return hose (3A713). Plug the reservoir fitting.

Attach an extension hose between the power steering return hose and an empty container.
Raise the front wheels off the floor; for additional information, refer to Section 100-02 .
Fill the reservoir.
Use Motorcraft MERCON® Multi-Purpose ATF XT-2-QDX or equivalent MERCON® fluid.

CAUTION: Do not crank the engine for more than 15 seconds at a time. Allow the starter to cool for 1 minute before cranking again. Premature starter failure can occur.

CAUTION: Do not hold the steering wheel against the stops for more than three to five seconds at a time. Damage to the power steering pump could occur.

Turn the steering wheel from stop-to-stop while cranking the engine until the fluid exiting the power steering return hose is clear of all contamination and debris.
Add Motorcraft MERCON® Multi-Purpose ATF XT-2-QDX or MERCON® equivalent as needed.

Lower the vehicle.
Disconnect the extension hose from the power steering return hose. Remove the plug. Attach the power steering return hose to the reservoir.

CAUTION: Do not overfill the reservoir.

Fill the reservoir.
Use Motorcraft MERCON® Multi-Purpose ATF XT-2-QDX or equivalent MERCON® fluid.

Install the air intake tube. Tighten the two clamps.

Install the IDM relay.

CAUTION: Do not hold the steering wheel against the stops for more than three to five seconds at a time. Damage to the power steering pump could occur.

Start the engine and turn the steering wheel from stop-to-stop.

NOTE: If the power steering system is noisy and accompanied by evidence of aerated fluid it will be necessary to purge the power steering system.

Check the power steering fluid level.
Use Motorcraft MERCON® Multi-Purpose ATF XT-2-QDX or equivalent MERCON® fluid

 

Hard Steering or Lack of Assist
Seized lower steering column shaft U-joints.
REPLACE the lower steering column shaft U-joints; for additional information, REFER to Section 211-04 .

Damaged, fractured steering column bearing(s).
REPAIR the steering column; for additional information, REFER to Section 211-04 .

Power steering pump.
GO to Pump Flow and Pressure Test in this section.

Suspension components.
REFER to Section 204-00 for suspension system diagnosis and testing.

Steering gear internal leakage.
GO to Pump Flow and Pressure Test under Component Tests in this section.

Excessive Steering Pump Noise
Power steering pump.
GO to Pump Flow and Pressure Test in this section.