bmart
New Member
I work for a equipment rental company here in Phoenix, AZ and we have four Genie S40/45 booms lift that the wheel lifts off the ground when turntable is rotated either clockwise or counterclockwise from stowed position. To give more of a detailed description, machine will be on level ground, primary boom fully raised to max height, rotate the turntable usually in the clockwise direction so I can watch the wheels. Once the counterweight is roughly 60-120 degrees from stowed position the back right wheel lifts off ground anywhere from 1/2" to 8" then I will have to immediately rotate turntable back opposite direction to counter it. I had first discovered this problem while I was in the platform and machine started to rock back and fourth while I was in the air. Some of the machines have had different components replaced compared to the others and one has not had anything replaced or adjusted but they all have the same problem.
Speed ahead to diagnosis/repair/set up. The oscillate system on this is purely hydraulic operated from its own pump. The pump has been replaced due to it first having no pressure output. The oscillate valve assembly replaced, the counter balance valves in the cylinders have been replaced and the cylinders have been rebuilt. I have verified pressure and flow through the whole oscillate system. I have leveled the machine to within .03 degrees. The oscillate system works properly when tested by driving any of the wheels onto a curb and verify that all three other wheels remain in constant contact with the surface. The machine should be able to complete full turntable rotation without any wheel lift at all. I have probably about 10-15 hours on the line with Genie production support. Been trying to figure this out for couple months now and it does not make sense. I can provide a link to the Genie service manual for this machine. In the manual it shows different pressures for the oscillate relief valve PSI (950 and 800 PSI) Genie reps have said use one or the other and that the relief valve PSI can be set to 75 PSI above max but if they can not tell me which one is max, I do not know what to believe. I have triple checked processes, hose routing to and from oscillate valve to oscillate cylinders and return, leveling, pressures and restarted whole setup. I am trying to make sense of this. It is a very simple and straight forward system but I am clearly missing something and I am very okay with admitting I have done something wrong. I can explain any specifics if needed.
Speed ahead to diagnosis/repair/set up. The oscillate system on this is purely hydraulic operated from its own pump. The pump has been replaced due to it first having no pressure output. The oscillate valve assembly replaced, the counter balance valves in the cylinders have been replaced and the cylinders have been rebuilt. I have verified pressure and flow through the whole oscillate system. I have leveled the machine to within .03 degrees. The oscillate system works properly when tested by driving any of the wheels onto a curb and verify that all three other wheels remain in constant contact with the surface. The machine should be able to complete full turntable rotation without any wheel lift at all. I have probably about 10-15 hours on the line with Genie production support. Been trying to figure this out for couple months now and it does not make sense. I can provide a link to the Genie service manual for this machine. In the manual it shows different pressures for the oscillate relief valve PSI (950 and 800 PSI) Genie reps have said use one or the other and that the relief valve PSI can be set to 75 PSI above max but if they can not tell me which one is max, I do not know what to believe. I have triple checked processes, hose routing to and from oscillate valve to oscillate cylinders and return, leveling, pressures and restarted whole setup. I am trying to make sense of this. It is a very simple and straight forward system but I am clearly missing something and I am very okay with admitting I have done something wrong. I can explain any specifics if needed.
