Does an electronic retrofit kit change the operating pressure or flow rate of the hydraulic system?
No; the kit drives the manual lever from outside, from above, and never touches the hydraulics. Pressure, flow and relief setting stay with the vehicle.
No. Kits such as the HCT400 and the HCT402 move the manual lever from outside, from above; they make no intervention in the hydraulic circuit, in the fluid or in the valves. The system pressure, the pump flow, the relief valve setting and the hose capacity all stay exactly as they were, as parameters belonging to the vehicle. The kit only determines which position the lever goes to and how fast.
Where does the kit touch the circuit
Nowhere. The servo motor grips the lever mechanically and drives its angular position according to the command coming from the joystick; the same motion the operator makes by hand is performed remotely and more repeatably. That is exactly why converting the lever without removing it is possible: no connection is opened at any point of the hydraulic circuit.
What the kit does not do:
- It does not increase or decrease the pump flow.
- It does not raise the system working pressure.
- It does not touch the relief valve, the load holding valve or the spool characteristic.
- It does not open any connection point in the hydraulic line.
What changes before and after conversion
| Parameter | After conversion | Set by |
|---|---|---|
| Working pressure | Unchanged | The pump and the relief valve setting |
| Pump flow | Unchanged | The pump and the engine speed |
| Ceiling on movement speed | Unchanged | Spool stroke and flow |
| Lever position and command speed | Changes | The kit and the joystick setting |
The first three rows of the table belong to the vehicle's own design. The working pressure and pump flow values are set by the vehicle and not by the kit; the pressure relief valve goes on being part of the circuit.
Two practical consequences of this
First, whatever the capacity of the existing hydraulic system is, it is the same after conversion; a slow system does not get faster when a kit is fitted. Driving the lever faster does not speed up the movement, because the limit is drawn by the relationship between spool stroke and flow. Second, your hydraulic safety elements stay in the circuit; the kit neither disables the load holding valve nor takes its place.
Against that, the kit does change the command, and that is where the gain lies. On a lever driven by hand the opening comes out a little different every time, whereas on a proportional joystick the same position gives the same opening. This repeatability makes the movement start more smoothly and the load swing less. In other words, while the capacity of the system stays fixed, how evenly that capacity is used changes.
Which expectation it does not meet
If your system has internal leakage, insufficient flow or low pressure, conversion will not put these right; on the contrary you will now notice more clearly that the movement is slow or unsteady, because the same command is given in the same way every time and the inconsistency of the system comes out. Driving more than one lever at the same time does not increase the total flow either: when you control more than one hydraulic lever with a single system the movements go on sharing the flow the pump provides. In the same way, when the kit is removed the vehicle returns exactly to its former manual operation, because no permanent change has been made on the hydraulic side; it is also possible to use the lever by hand while the kit is installed.
What to do
Note the current movement times before conversion: how many seconds does one lift and one lower take? Repeat the same measurement after conversion. If there is no difference between them, the kit is working correctly. If the movement is slower than you expected, the place to look is not the kit but the hydraulic side: first the oil level and the filter, then the pump and the relief valve setting.
The full topic: What is a hydraulic lever retrofit kit?