A cycle-time test times the main movements under fixed conditions and compares them with a specification or with a baseline recorded when the machine was known good. Time boom raise, arm in, bucket curl, swing and travel separately, at rated engine speed, with the oil at operating temperature and the same attachment fitted. Record each three times and average. Uniform slowness across every movement points at pump flow or engine speed. One slow movement points at that circuit. Slowness that only appears when the oil is hot points at internal leakage. The numbers decide which of those you investigate, and they cost nothing but a stopwatch.
What you will notice
| Symptom | What it usually points to |
|---|---|
| It feels slower than it did last season | Feel is not evidence. A baseline recorded earlier turns the impression into a comparison. |
| You have just bought a used machine | A cycle-time test is the cheapest way to find a tired circuit before it fails on site. |
| A pump or valve was replaced and you want proof | Timing before and after shows whether the repair addressed the actual restriction. |
| Two machines of the same model perform differently | Timing both under the same conditions shows which one has a fault and which one is simply set differently. |
| A performance dispute with an operator or a buyer | Recorded numbers with the conditions noted are evidence. Opinions are not. |
Most likely causes
| Cause | How to confirm it |
|---|---|
| Cold oil | Cold oil is thick and slow. Time only at operating temperature or the numbers describe viscosity, not condition. |
| Engine below rated speed | A machine at low idle is slower by design. Verify rated speed on the monitor before you start the watch. |
| A different bucket or load | Mass changes the result. Use the same attachment and the same load for every run, and note what it was. |
| A different operator | Lever travel and technique vary between people. One operator, three runs, average the last two. |
| Two functions moving at once | Combined operation shares pump flow, so both movements slow. Test one function at a time with everything else at rest. |
The movements worth timing, and what a slow result points to
| Movement | What a slow result points to |
|---|---|
| Boom raise, ground to full height | Pump flow, main relief, boom circuit restriction. |
| Arm in, full stroke | Arm circuit, regeneration valve, cylinder seal bypass. |
| Bucket curl, empty then loaded | Bucket circuit and linkage. Compare loaded against empty. |
| Swing 90 degrees, each direction | Swing relief, brake release, motor condition. |
| Travel 20 meters, straight, level ground | Travel motors, final drives, track tension. |
| All movements, oil at 60 to 70 degrees | Uniform loss means pump or engine. One slow movement means that circuit. |
How to confirm it
- Warm the machine under load
Work it for at least twenty minutes so the oil reaches operating temperature. A cold test measures viscosity and tells you nothing about wear.
- Fix reference points on the machine and the ground
Mark the boom, the arm and a point on the ground with tape. Fixed references remove operator judgment from where a movement starts and ends.
- Time three runs and average the last two
Start the watch when the lever moves and stop it when the movement finishes. Discard the first run, which always includes hesitation.
- Record the conditions beside the numbers
Engine speed, oil temperature, attachment, load and operator. A number without its conditions cannot be compared with anything recorded later.
- Compare with the specification or your own baseline
Manufacturer figures are the reference for a new machine. A baseline from the same machine, recorded when healthy, is the reference for wear.
- Repeat the slow movement with a pressure gauge
Slow with correct pressure is a flow restriction. Slow with low pressure is a relief or the pump. The gauge decides which, and the stopwatch alone cannot.
What to do about it
If every movement is slow by a similar proportion, suspect pump flow, engine speed or a main relief that is opening early. Measure flow at rated pressure before adjusting anything, because a pump that is worn cannot be tuned back to specification.
If one movement is slow, work on that circuit only: relief setting, spool stroke, cylinder bypass and hose restriction. Replacing a pump because the arm is slow is the most expensive way to learn this lesson.
If the machine is only slow when hot, measure the same movements cold and hot and compare the loss. A drop of more than about fifteen percent between the two is internal leakage, and the case drain measurements tell you which component.
Write the numbers into the machine file with the date and the conditions. The next time someone says the machine feels slow, the comparison takes ten minutes instead of a service visit.
Pumps, relief valves, cylinder seal kits and travel motors are supplied by Guangzhou Shenyue Machinery Technology Co., Ltd., which holds 3,000+ part types on the shelf and 100,000+ part numbers available to order, each line marked as genuine, OEM-quality or aftermarket.
Parts you may need, by grade
| Part | Grades commonly quoted |
|---|---|
| Main hydraulic pump | Genuine; OEM-quality; remanufactured where offered. Match by casting number and regulator type. |
| Main relief valve | Genuine; OEM-quality. Match the setting and the seat style, not just the thread. |
| Cylinder seal kit | Genuine; OEM-quality. Match by cylinder part number, not by rod diameter alone. |
| Travel motor and final drive | Genuine; OEM-quality; remanufactured where offered. Confirm two-speed ratio and brake type. |
| Flow meter and test gauge set | Workshop tooling rather than a machine part. A calibrated gauge is worth more than a decade of opinion. |
Need the parts this covers?
Send the machine model, serial number and the part numbers you need. We confirm fitment before payment and state the grade of every line — genuine, OEM-quality or aftermarket.
Request a quoteFrequently asked
How accurate does a stopwatch test need to be?
Close enough to see a trend. Differences under about ten percent are within operator variation; differences above fifteen percent are real and worth investigating. Three runs and an average get you there.
Where do I find the specification for my machine?
In the service manual, usually as cycle times at rated speed with a specified oil temperature. If the manual is missing, record your own baseline on a healthy machine of the same model and use that.
Can I time movements with a phone?
Yes, as long as you start and stop on a visible reference rather than on feel. Video is better, because you can replay it and read the frames when the movement actually starts.