There are four main parts to a truck or bus hydraulic system; the control valve, hydraulic pump, fluid, pistons and cylinders. Within a bus, truck or industrial hydraulic system the Power Take Offs are critical to enabling function.
It is therefore important that you include the PTO, alongside the splined drive shaft and full gear system within the standard vehicle maintenance checks.
Power takes-offs (PTOs) are mechanical devices that are connected to the gear systems of commercial vehicles where they receive the driving power and transfer it to other mechanical devices like hydraulic pumps.