A running lubrication motor does not prove that oil or grease reaches the required bearing or cam. A paper cup machine lubrication pump can receive a command yet fail to prime, discharge through a relief path, or feed a leaking line. The useful diagnostic question is where confirmed delivery stops.
First identify the system: oil or grease, manual or powered pump, and single-line, progressive or another distribution arrangement. The expected pressure and cycle behavior depend on that design. Do not keep production running when a critical lubrication point has no verified supply.
Diagnostic decision table
| Evidence | Possible boundary of fault | Next confirmation |
|---|---|---|
| No pump command | Control schedule or permissive | Read the intended cycle and input status |
| Motor runs, no pressure rise | Reservoir, suction or pumping stage | Use the approved pump test point |
| Pressure rises, points remain dry | Distribution or blockage | Check the system-specific outlet sequence |
| Pressure cannot build, lubricant escapes | Line or connection leak | Locate the loss after safe isolation |
Preserve the lubrication cycle evidence
Record the alarm, time since the last confirmed cycle, operating mode and the machine station affected. Some pumps are controlled by elapsed time while others depend on machine cycles. Compare the observed interval with the actual programmed schedule before diagnosing a stopped pump.
Capture command output, motor response and any pressure or cycle feedback on one timeline. A feedback lamp may indicate a switch state rather than delivered volume. Preserve these distinctions in the maintenance record so the next technician does not interpret every green indication as proof of lubrication.
Check the reservoir and lubricant identity
Verify level at the machine state specified by the pump manual. Inspect the correct lubricant label, refill history, contamination evidence and any foaming or separation. A full reservoir containing the wrong viscosity or consistency is not an acceptable baseline. Check that the approved filling and venting arrangements are intact.
If the reservoir recently ran empty or a suction connection was opened, the pump may need its documented priming procedure. Do not loosen pressurized fittings to search for flow. Isolate energy and release stored pressure through the designed method before accessing the supply path.
Separate electrical drive from pumping action
Qualified personnel should compare the control command with actual motor operation or solenoid actuation. Inspect connectors, drive coupling and indicated rotation where these checks are applicable. A motor that turns while its mechanical connection is damaged can sound normal at a distance.
Use the pump manufacturer’s designated test procedure to establish pressure or discharge. Record test point, lubricant temperature and duration. Avoid deadheading an unknown pump or adjusting the relief valve to obtain a reassuring gauge reading. Those actions can damage the system or conceal the reason flow is absent.
Follow the distribution design
On systems that build and release pressure to reset metering units, failure to release can prevent the next dose. Progressive distributors behave differently, and a blocked downstream point may affect other outlets. Read the circuit diagram before interpreting a stationary indicator or gauge.
Inspect accessible lines for breaks, crushed sections and disconnected fittings. Compare outlet evidence through the approved checking method, using clean collection and contamination controls where required. A high-pressure reading at the pump can coexist with a dry mechanism; pressure and delivery must be verified separately.
Prove delivery before restarting production
After the fault is corrected, verify the required lubrication points through a complete operating cycle. Restore each opened connection and guard, remove temporary collection equipment and check that feedback responds as specified. Record both successful delivery and the absence of new leakage.
Assess whether operation without lubrication may have damaged a bearing, cam or guide. A restored pump cannot reverse existing wear. Send HANNAI the pump label, lubricant identity, circuit diagram, command timeline and point-by-point result. These records help distinguish a replacement pump request from a distribution repair.
Related equipment and next checks
Review the HN-M100 forming machine and the related guide to lubrication distribution inspection. The Engineering Notes archive connects these checks with wider machine planning.
Frequently asked questions
Does motor noise prove the pump delivers?
No. Verify discharge and delivery at the required points.
Can every system be tested the same way?
No. The distribution design determines its pressure and reset behavior.
Should the relief setting be increased first?
No. Identify the fault using the approved test procedure.
Can production resume as soon as an alarm clears?
Only after required delivery and possible starvation damage have been assessed.
Review the evidence with HANNAI
Send your machine model, component identification and the observations described in this guide. Include the drawing or material reference and any before-and-after measurements so the required next check can be identified.