I am working on a cat M50D that has a problem with the power steering system. The steering pump is very slow to power up when you start driving, infact some times you need to "saw" the whell back and forth to get it to start. I have several customers that have the Daewoo version (BC25 I think) of the same machine, and they never have this problem. I noticed that there is a pressure sensor near the orbital valve in the steering column; is the most likely cause of the problem, or is there some thing else that I should check out first. When the powewr steering does start up, it steers normaly and gives no indication of some thing like a worn out piston seal in the P/S cyl, but thats just a seat of the pants diagnosis.