How to care for and maintain the hydraulic powerpack and control valves on the Simpro Multi-Tip bin lifter.
Overview
The Multi-Tip electric motor, pump, oil tank, and all control valves are mounted into one integral unit, referred to as the ‘powerpack’.
The control valves are:
- Check valve
- Pressure-relief valve
- Lowering valve
There is an oil-level gauge on the side of the main box; the level should be approximately in line with the upper indicators when the cradle is fully lowered.
The powerpack is very reliable and long-lasting, and no regular maintenance is required. Possible faults include:
- Foreign matter in the lowering valve (symptoms – raising slowly or not at all, coming back down without pushing the Lower button)
- Blocked suction strainer (raising slowly or not at all, noisy operation)
- Worn shaft or shaft seal (slow lifting, noisy operation, oil foaming)
- Low oil level (normally only following an oil leak)
- Worn brushes
Removal and refitting
- Ensure the cradle is fully lowered.
- Loosen the screws holding the outer cover and remove it.
- Make note of the wiring connections to the motor and disconnect.
- Undo the knurled knob holding the lowering solenoid coil on and remove it.
- Undo the swivel fitting holding the hydraulic hose to the power pack. Plug or tape the fittings to prevent ingress of dirt.
- Undo the two bolts or screws holding the power pack mount bracket and lift it away.
Refitting is a reversal of the above procedure, with attention to the following points:
- Ensure the wiring is reconnected the same as original.
- Do not use thread sealant on the hydraulic fitting.
- Test for correct operation before refitting the cover.
Check valve
The check valve prevents the oil from flowing back through the pump when the motor is stopped. It very rarely fails, but if some foreign matter gets in, it may not seal properly, allowing the cradle to come down when the Raise button is released.
Removal and refitting
A special tool is needed to extract the check valve. Please contact Simpro if you think it may need to be removed.
Pressure-relief valve
The pressure-relief valve limits the maximum hydraulic pressure flowing to the ram, and thus the maximum weight that can be lifted. If the bin is heavier than the setting will allow, the motor and pump still run but the oil bypasses straight back into the tank. While this does not do any harm to the machine, oil passing through the relief valve generates a lot of heat; for this reason, if the relief valve is ‘blowing’ frequently, either the setting should be increased, or the bin weight reduced.
Removal, adjustment and refitting
Authorization must be obtained from the manufacturer before any adjustment is made to the pressure-relief valve. Unauthorized adjustment may void the warranty.
- Remove the cover panel from the powerpack compartment.
- The pressure relief valve is located on the top of the main power pack body, beside the red lowering solenoid.
- Remove the outer cap, loosen the locknut then turn the screw clockwise with a 6mm Allen key to increase the pressure.
- Test the capacity using a full bin. In general, the most pressure is required just as the bin starts to tip, so check it at this point. When pressure setting is sufficient, tighten the locknut, and replace the outer cap.
- Refit the cover panel.
The pressure should be set to just a little higher than necessary to pick up the heaviest bins.
Lowering valve
The Multi-Tip lowering valve is operated by an electric solenoid connected to the control circuit. When opened, it allows oil to flow from the hydraulic ram back into the reservoir, causing the cradle to descend.
Removal, cleaning and refitting
- Unscrew the retainer nut and slide the coil off.
- Unscrew the valve from the main body using a ring spanner.
- Clean the valve carefully with compressed air. Ensure that the centre poppet can move freely, and then it seals firmly on the valve seat when released.
- Clean the valve orifice.
- Refit the valve.