I need information, everyone I talk to has no idea what what the problem is. I have a 1997 GM 1 ton cab chassis truck. It has a 9' Knapheide brand dumping flatbed with an electric pump. The platform raises and lowers fine, the problem is, after its lowered and resting tightly on the subframe it raises 1/2 inch within 5 minutes, weather the truck is parked or driving. Then when its a 1/2 inch of the frame it constantly bounces. Also, if someone could recommend a place to service the dump bed in the Detroit metro area, I would really appreciate it.