My son in law has about a 1984 Olds Cutlass. He says the power steering is only working when he turns to the left. When he turns to the right he says it is like manual steering. He says it is full of fluid and the lines all look good, no leaks or anything. Would a bad pump do this? Any suggestions are welcome.

Sounds like a biding Rack, try flushing the system out. R&R the return line and run it to an empty jug, fill the system and rotate steering side to side (better if it's jacked up) use 2 liters Trans fluid to flush it, and 2 liters of P/S fliud. Once flush is complete for good measure I use a bottle of Lucas power steering stabilizer.

Hope this helps. Cheers Chevyboy454.

Sounds like you have a stuck or clogged check/control valve in the gearbox. I'd follow the flushing recommendation given above and see if that helps. I would wait to try the lucas until after you see if the flush helps, if it frees it up then I'd spend the money on the Lucas to help freshen seals/clean orifices.