Suspension system tank filling systems and methods

1. A system for filling a tank of a suspension system with hydraulic fluid, the system comprising:

a module configured to turn on an external pump and pump hydraulic fluid into the suspension system,

wherein the external pump is separate from the suspension system and is configured to pump hydraulic fluid into the suspension system via a port fluidly connected to a hydraulic line of the suspension system; and

a fill module configured to, after operating the external pump, operate a pump of the suspension system and pump hydraulic fluid from the hydraulic line into the tank of the suspension system thereby filling the tank.

2. The system of claim 1 wherein the fill module is configured to operate the pump and pump hydraulic fluid from the hydraulic line into the tank of the suspension system when a pressure within the hydraulic line is greater than or equal to a first predetermined pressure.

3. The system of claim 2 wherein the fill module is configured to operate the pump and pump hydraulic fluid from the hydraulic line into the tank until the pressure within the hydraulic line becomes less than or equal to a second predetermined pressure.

4. The system of claim 3 wherein the second predetermined pressure is less than the first predetermined pressure.

5. The system of claim 1 wherein:

the module is further configured to, after operating the pump and pumping hydraulic fluid from the hydraulic line into the tank, turn off the external pump; and

the fill module is configured to, after the external pump is turned off, operate the pump and pump hydraulic fluid from the tank into the hydraulic line.

6. The system of claim 5 wherein the fill module is configured to operate the pump and pump hydraulic fluid from the tank into the hydraulic line until a pressure in the hydraulic line is greater than or equal to a predetermined pressure.

7. The system of claim 6 wherein the fill module is configured to determine a total volume of hydraulic fluid pumped into the tank based on a volumetric flowrate of the pump while the pump pumps hydraulic fluid from the tank into the hydraulic line.

8. The system of claim 7 wherein the fill module is configured to determine the volumetric flowrate based on at least one of a voltage applied to a motor of the pump, a current through the motor of the pump, a temperature of the pump, and the pressure in the hydraulic line.

9. The system of claim 8 wherein the fill module is configured to:

determine a number of additional pressurizations of the hydraulic line to perform based on the total volume pumped into the tank and a predetermined target volume; and

operate the external pump to perform the additional number of pressurizations of the hydraulic line.

10. The system of claim 1 wherein the tank is sealed such that hydraulic fluid cannot be added directly into to the tank.

11. The system of claim 1 wherein hydraulic fluid can only be added to and taken out of the suspension system via the port that is fluidly connected to the hydraulic line of the suspension system.

12. A method for filling a tank of a suspension system with hydraulic fluid, the method comprising:

turning on an external pump and pumping hydraulic fluid into the suspension system,

wherein the external pump is separate from the suspension system and is configured to pump hydraulic fluid into the suspension system via a port fluidly connected to a hydraulic line of the suspension system; and

after operating the external pump, operating a pump of the suspension system and pumping hydraulic fluid from the hydraulic line into the tank of the suspension system thereby filling the tank.

13. The method of claim 12 wherein operating the pump and pumping hydraulic fluid from the hydraulic line into the tank of the suspension system includes operating the pump and pumping hydraulic fluid line into the tank when a pressure within the hydraulic line is greater than or equal to a first predetermined pressure.

14. The method of claim 13 wherein operating the pump and pumping hydraulic fluid from the hydraulic line into the tank includes operating the pump and pumping hydraulic fluid from the hydraulic line into the tank until the pressure within the hydraulic line becomes less than or equal to a second predetermined pressure.

15. The method of claim 14 wherein the second predetermined pressure is less than the first predetermined pressure.

16. The method of claim 12 further comprising:

after operating the pump and pumping hydraulic fluid from the hydraulic line into the tank, turning off the external pump; and

after the external pump is turned off, operating the pump and pumping hydraulic fluid from the tank into the hydraulic line.

17. The method of claim 16 wherein operating the pump and pumping hydraulic fluid from the tank into the hydraulic line includes operating the pump and pumping hydraulic fluid from the tank into the hydraulic line until a pressure in the hydraulic line is greater than or equal to a predetermined pressure.

18. The method of claim 17 further comprising determining a total volume of hydraulic fluid pumped into the tank based on a volumetric flowrate of the pump while the pump pumps hydraulic fluid from the tank into the hydraulic line.

19. The method of claim 18 further comprising determining the volumetric flowrate based on at least one of a voltage applied to a motor of the pump, a current through the motor of the pump, a temperature of the pump, and the pressure in the hydraulic line.

20. The method of claim 19 further comprising:

determining a number of additional pressurizations of the hydraulic line to perform based on the total volume pumped into the tank and a predetermined target volume; and

operating the external pump and performing the additional number of pressurizations of the hydraulic line.