Ive been having hard steering problems on a Sellick S80 forklift. Problem seem to have started a couple years ago after the operator filled the hydraulic tank with diesel fuel and when running the machine on low hydraulic oil. Now after a couple damaged hydraulic filters replacements, the steering problem has become more difficult to work the steering to 90% operational. Recently I opted to replace the steering obital pump but didnt resolve the hard steering. After running the machine, Im back to 90% steering ability. At 90%, the steering sensitivity is very dull to changing steer direction, and requires a short delay with light pressure on the steering wheel before the power steering kicks in. Ive also noticed in order to have a quicker steering response, Id have to tap the brakes which is also hydraulically assisted. Im now leaning on a possibility of some sort of hydraulic pressure to steering orbital problem, and now im researching if the charging valve is bad. Any help is appreciated.