I have an old hyster h50f, my first forklift for around the shop. The problem is that it has no power to go up hills, all other hydraulics work fine. When you hit the monotrol pedal, it just Boggs down, checked pressures on valve body and everything seems good. Cleaned the inching valve and made sure that was working. Can a bad monotrol pedal cause this? It's the purely hydraulic version. Any help would be appreciated.