Hydraulic Response Problems During Harvesting Season
During the harvesting season, slow hydraulic response can interrupt a combine harvester's working cycle. When the header takes longer to lift, or responds poorly after the machine warms up, technicians need reliable measurements to guide the repair instead of guesswork. Field conditions leave little room for trial-and-error repairs, so the ability to measure hydraulic performance quickly and accurately directly affects how many hectares a machine can cover each day.
Portable Measurement Directly at the Machine
The HIGHLAND MYHT series portable hydraulic tester measures flow, pressure, and oil temperature. Its compact design and rechargeable battery supply allow service teams to bring hydraulic measurement equipment to the machine, supporting both field repairs and workshop diagnosis. Because the tester travels to the harvester rather than the harvester travelling to a test bench, a dealer's service team can complete an initial assessment in the field and decide immediately whether the machine can continue working or must be brought in for further service.
A Structured Header-Lift Investigation
In a typical header-lift investigation, technicians first review the machine's hydraulic schematic and service procedure. With a suitable tester and test arrangement, they can assess hydraulic supply under defined operating conditions and compare the readings with the manufacturer's specifications. Working from the schematic keeps the test focused: it identifies the pump, the priority valve, the lift circuit, and the test points that represent the system rather than a single component.
| Measurement | What It Reveals | Why It Matters for Header Lift |
|---|---|---|
| Flow (L/min) | Actual oil volume delivered to the circuit | Confirms whether the pump can supply enough oil to raise the header at normal speed |
| Pressure (bar/psi) | System load and relief behaviour | Identifies restriction, internal leakage, or a relief valve opening early |
| Oil temperature (°C) | Thermal condition at the moment of testing | Explains symptoms that appear only after the machine warms up |
| Engine speed (rpm) | Operating point of the pump drive | Keeps results comparable between tests and between machines |
Why Flow and Pressure Must Be Measured Together
A pressure reading alone does not establish whether enough flow is available. Measuring flow and pressure together, while recording oil temperature and engine speed, provides a clearer basis for evaluating performance. If the hydraulic supply meets specification, further checks can focus on the relevant valve, cylinder, or control arrangement. This sequence prevents the common mistake of replacing a healthy pump when the real restriction sits downstream in a valve block or a partially blocked suction line.
- Supply confirmed, symptom persists: move on to valve, cylinder, or control diagnostics.
- Flow below specification: inspect pump condition, suction side, oil viscosity, and filtration.
- Pressure dropping as temperature rises: look for internal leakage that only appears in warm oil.
- Readings unstable: check test connections, air ingress, and the loading procedure itself.
Verifying the Repair Afterwards
The same measurements are useful after repair. Repeating the test under comparable conditions helps technicians check whether performance has returned to the required level. Recording these results also provides a maintenance reference for future inspections, so the next time the same machine shows a slow header lift, the workshop already has a baseline to compare against rather than starting from zero.
Selecting the Right Tester
Tester selection should match the circuit's expected flow and pressure, including the measurement range needed for the particular function. Connections and loading procedures must follow the equipment instructions. Choosing a range that is too wide reduces resolution on low-flow circuits, while a range that is too narrow risks damaging the instrument during pressure peaks.
Supporting Dealers and Repair Workshops
For agricultural machinery dealers and repair workshops, MYHT testing supports an evidence-based repair process: investigate the symptom, assess hydraulic performance, and verify the completed work. Instead of relying on operator descriptions alone, service teams can document measured values and present them to the machine owner, which shortens discussions about warranty and service scope and builds confidence in the repair.
About HIGHLAND
HIGHLAND supplies hydraulic testing instruments for agricultural, construction, and industrial service applications. The MYHT series is designed for technicians who need dependable hydraulic data in the field, with a portable form factor that keeps measurement tools close to the machine. For technical selection guidance, please contact our team with your circuit's expected flow range, working pressure, and test point details.
