Bobcat code M0509: Hydraulic charge pressure too low

Check first

1. Park on level ground, lower the lift arms and attachment to the ground, stop the engine and remove the key.
2. Check the hydraulic fluid level in the sight gauge and top up with the fluid listed in the O&M manual.
3. Never feel for a leak with your hand. Use cardboard; a pinhole leak can inject oil under the skin.
4. Replace the hydraulic/hydrostatic filter if it is due.
5. If the code returns with good fluid and a new filter, have charge pressure tested.

Likely causes

• Low hydraulic/hydrostatic fluid level
• Leak in a hose or fitting
• Plugged hydraulic/hydrostatic filter
• Faulty charge pressure sensor or wiring
• Worn charge pump

The fix

Most fixes are fluid level, leaks or a plugged filter. A dealer can measure charge pressure if the cause isn't obvious. Bobcat warns that running with a warning active can damage the engine or hydraulic system.