Fault Phenomenon: SANY SR285 rotary drilling rig during rapid feed or extraction, the hydraulic system pressure fluctuates severely, actions become jerky.

Troubleshooting Process:
– Checked accumulator: bladder ruptured or valve core leaking.
– Checked pre-charge pressure: nitrogen pressure zero.
– Checked mounting: accumulator mounting loose.
– Checked fluid: increased air bubbles in oil.

Root Cause: The bladder in the pulsation damping accumulator at the main pump outlet ruptured, causing nitrogen to leak and losing the function of absorbing pressure pulsation and supplementing instantaneous flow.

Required Parts: Replace hydraulic accumulator bladder or assembly, recharge with nitrogen.