Power steering yes/no

I replaced the leaky low pressure hose yesterday, filled it up and cycled the steering wheel until the buzzing noise stopped. This morning I checked the fluid and it was full, so I took it out for a test drive. Drove three miles with power steering and then it stopped working. Fluid is still topped off, so there are no leaks and there is no buzzing from the pump.

What's the proper troubleshooting sequence now????

If there is no air in it and the fluid is full, either the pump is bad or the gear is bad. The thing to do would be check pump pressure, but you would most likely need to go to a shop for that since most people dont have a p/s pump pressure gauge lying around. I have seen pump shafts break on several occasions, ususally on GM vehicles, but suppose it could happen on anything. Get a prybar between the pully and the housing and see if you can pry the pully outward. If it slides out, the shaft is broken.

Checked the pump pulley and nothing seems out of the ordinary. It spins freely with no binding. Looks like its a trip to the mechanic for this one. I'm not about to start replacing the pump or rack. It would be a crap shoot.

Good call on getting it looked at and not throwing parts at it. I read post after post of guys just throwing parts to fix a problem, then get upset that their car is costing them so much! If they just did, or had, a proper diagnosis, the repairs would have been less costly! Good luck, and please post the results!