Seat suspension system having fail-safe functionality

A suspension system for a mobile machine, comprising:

• a seat operatively connected to a cabin floor of the mobile machine;
• a cylinder connected between the seat and the cabin floor;
• a spring associated with the cylinder;
• and
• at least one valve configured to regulate fluid flow into and out of the cylinder, wherein:
• the at least one valve includes a valve element that is movable from a less-restrictive position at which fluid flow is substantially unrestricted by the at least one valve, through a default position at which fluid flow through the at least one valve is restricted by an amount that still allows fluid flow through the at least one valve, to a second more-restricted;
• and
• the at least one valve is biased to the default position and selectively moved to the first or second positions when energized.

A seat dampening method for a mobile machine, comprising:

• pressurizing fluid;
• selectively directing pressurized fluid into and out of a cylinder associated with an operator seat to dampen movement of the operator seat;
• detecting a failure condition of the mobile machine;
• and
• restricting fluid flow into and out of the cylinder by an amount that still allows fluid flow into and out of the cylinder during the failure condition.