power steering issues/Somona 4WD 2000

My power steering sometimes doesn't work when moving slow like backing out of the driveway whether I'm turning left or right. If I quit fighting it, it seems to come right back to normal. Intermittment problems. Frustrating. Level looks normal. Color looks normal. Not sure where to start. 2000 GMC Sonoma SLS 4WD High Rider.

Start by checking the serpentine belt and tensioner. If they haven't been replaced in 50,000 miles, they're due.

Thanks for the response. I wasn't aware that the tensioner needed regular replacement. The tension does seem to be fine. I can't remember when the belt was replaced.

The tensioner automatically keeps the proper tension on the serpentine belt. Over time, the spring inside the tensioner weakens and the belt loosens up. When the belt is too loose, the alternator, power steering pump, air conditioning compressor and water pump can slip. Sometimes the belt will squeel, sometimes it will not. There is a pointer and two notches on the tensioner, the pointer should be between the notches when the engine is running. Rule of thumb is when you replace the belt, replace the tensioner at the same time. While the belt is off, check all of the other pulleys, especially the idler pulley, for smooth, quiet operation, (service or replace as necessary).