How does the bucket on a dump truck work?
The dump truck contains a hydraulically power controlled
cylinder that expands as fluid is injected, resulting in the "dump"
trailer lifting from the frame of the vehicle. This system is
referred to as a PTO, or Power Take-Off.
Please give a specific model. The dump bodies and hydraulic system will be aftermarket, but you there's no way to tell you anything if we don't know whether you're talking about a 1/2 ton C/K pickup or one of the Class 8 trucks Chevrolet manufactured at the time (Chevrolet exited that market in 1980; GMC followed suit when their heavy truck division was bought out by A.B. Volvo in 1988).
The answer depends on which altec bucket truck you look at. For example the Altec AA755 MH- 2004 International 4300 Bucket Truck has a gross weight of 33.000 lbs but the ALtec AM855- 1998 International 4900 4x4 Bucket Truck has a gross weight off 39.000lbs. But on average the bucket trucks are around the 30.000 lbs.