My power steering comes and goes on my 86 K5. This started the other day when I was cutting some donuts. I remember cutting donuts and then hearing the pump squeel some. I let off the gas and straightened out the wheels. At that point I had no power steering. I parked my k5 and went to bed cause it was late. The next morning I checked my fluid, which was full. I started the truck and I had steering again. I've been drivin it since. The powersteering seems to come and go. I lose it ususally when I have been driving the truck and everything warms up. So what did I do? Did I burn up the pump? Should i take a hose off and drain the fluid and put more in and then bleed the air? Any other advice?