I've had my 08 F250 for a few weeks now and I've notice an issue I'd like to figure out. Occasionaly, when coasting for a bit (downhill), with my foot off the pedal, I'll go to brake and the brake is abnormally stiff for a few seconds, then goes back to normal. At the same time, I have no power steering. If i hit the gas or brake harder, it instantly clears up. I happens every few days or so. I initially thought it was the power steering pump going out, but that doesn't explain the weird brake feeling. Any ideas?

 

i am guessing you have a oil burner or a truck thats over 10,000gvw they have hydraboost instead of vacume boost might want to think about a good flush of your power stearing pump and new oil

 

If you don't have the big round disc behind the master cylinder you have a hydraulic hydroboost power assist that gets it's hydraulic pressure off the power steering pump.

Can be a pump issue, air in fluid issue, or a hydroboost going bad effecting both the steering and brakes at the same time.