What Operating Conditions to Record for Overheating Issues
If the seller mentions hydraulic overheating, start by recording the symptoms and the work being performed when they occur. For the specific machine, check the radiator, fan, thermostat, pump or motor internal leakage, relief-valve settings, brake drag and compatibility of the tool with the hydraulic system.
Record the work the machine is performing as the temperature rises, how long the rise takes, the ambient temperature and what changes after unloading. These records can help a technician plan checks and assess possible repair costs and purchase terms.
Why generic temperature limits can be misleading
Temperature values are meaningful only when tied to the exact machine, sensor location, alarm logic and operating conditions. Acceptable continuous ranges and test procedures must come from the operating and maintenance documentation for that configuration. Thresholds must not be carried over from other models or from general promotional material.
Some rigs have different operating temperatures and derating behavior under different loads. Request the operation and maintenance documents for the specific machine and configuration, and assess it under the conditions they specify. If the documents are unavailable, record the relevant temperature information for verification.
First establish a cold-state test baseline
Before carrying out any type of heat test, establish a cold baseline. Record the ambient temperature, the hydraulic oil temperature when the machine is first started, and the oil level. Record the oil grade and, if possible, take a sample for laboratory analysis. An oil level that is too low or incorrect viscosity can cause overheating, and simply topping up or changing the oil may mask deeper problems.
Check the radiator fins, fan drive and fan belt or hydraulic fan motor. Dust, mud or abnormal fan operation can affect cooling; you can photograph the condition before and after cleaning. Internal leakage in the pump, motor or valves can also increase heat and should be assessed alongside other findings.
Timed Work Cycle: Reproducing the Fault Symptom
The core of testing is a repeatable work cycle that matches the tasks associated with the complaint. A qualified operator and technician should determine duration, load, readings and stop conditions based on the machine manual and a site risk assessment. Record hydraulic and coolant temperature trends, fan behavior and fault indications at fixed intervals; pressure measurements should be taken by trained personnel using approved ports and instruments.
If the seller permits only an unloaded demonstration, record that performance under load remains unverified. Where equipment and site safety conditions permit, have qualified personnel arrange a working cycle related to the reported problem in accordance with the applicable manual. If this cannot be done, account for the outstanding checks and possible diagnostic costs in your offer.
Look at temperature trends, not peak values
Record temperature changes over time, whether an alarm occurs and what changes after unloading. A technician can assess the readings and trend alongside the sensor location, actual work and the applicable machine manual.
Record the time of the alarm, the time of recovery, and the temperature when the system is stable. If the alarm resets automatically, record that fact, and do not reset it manually before recording the first occurrence. A machine that repeatedly alarms under the same conditions has a real problem, regardless of how the seller claims it only needs a simple fix.
Distinguishing cooling, oil and pressure causes
Once trend data is available, qualified personnel can check the cooler, fan, relief-valve settings, circuits, pump, motor and control valves according to the applicable manual and site safety conditions to investigate possible causes.
If the temperature rises mainly under load, check the oil level and grade, workload, and whether the drilling tool matches the machine’s flow and pressure capacity. Assess machine condition and suitability for the work separately in light of the inspection findings.
Retest according to the same procedure after replacing parts
After replacing the cooler, fan or thermostat, retest using the same procedure and record the results to compare performance before and after repair.
If the seller refuses to allow a re-test, treat the overheating problem as unresolved. In that case, you should price the diagnosis and repair costs separately from the purchase price, and make your offer conditional on a successful re-test after repair. This protects you from buying a machine that still overheats once it is in your hands.
Record leakage and pressure readings
From a safe position, record leaks before and after the test and note whether the equipment was running or stopped when they occurred. Have qualified personnel inspect seals and connections in accordance with the manual. A jet of pressurized fluid can penetrate the skin and cause injury.
Have trained personnel use the specified test points and tools to read pressure in accordance with the applicable manual and site safety conditions, then compare the readings with the relevant specifications. For high pressure with high temperature, personnel can check the relief-valve settings and circuit; for low pressure with high temperature, they can check the pump and internal leakage, then assess the findings alongside other checks.
Match the drilling rig to your work cycle
Before requesting a quote, first record your expected working conditions: drilling type, average depth, tool size, ambient temperature range and altitude. Compare these with the rig's published maximum flow, pressure and power specifications. If your conditions are more demanding than the rig's design range, overheating may occur even if the machine is in fully good condition.
If the equipment specifications do not meet the intended work, first check whether the tool or work plan can be adjusted, then compare equipment that meets the requirements and reflect the existing machine’s limitations in the offer.
Your Inquiry: What to Ask For and How to Move Forward
When you submit an inquiry through GLOBMACH, state clearly what evidence you need. Ask for the exact stock ID, the operation and maintenance manuals, the repair history, and any prior inspection reports. Request a load-test cycle that matches your expected working conditions, and ask for the temperature records and pressure readings from that test.
If a full test cannot be carried out, ask for a written statement on the overheating history, including the operating conditions at the time and any repairs already attempted. Then build contingency terms into the quote: a price adjustment for any unresolved diagnosis, or retention money released only after a successful retest. This way you control the risk, and the seller knows you are serious about the technical assessment.
