A hydraulic pump part number usually combines the component maker's pump series code with the machine maker's assembly number, and both matter. The series identifies the physical unit — a K3V112 series pump is a different unit from a K5V140 regardless of which machine it is bolted to — while the assembly number identifies how that pump was configured for a specific build, including its regulator and control type. Quote both, plus the machine serial number.
What each marking tells you
| Marking | What it tells you |
|---|---|
| Pump series code, stamped on the body | The physical pump family and displacement. This is what determines whether the unit is dimensionally and hydraulically the right starting point. |
| Machine maker's assembly number | How that pump was configured for a particular machine: regulator, control type, port arrangement and settings. The same series carries different assembly numbers for different builds. |
| Regulator or control designation | Whether the pump is controlled by negative flow, positive flow or load sensing. The right series with the wrong control type produces a machine that runs badly without being obviously broken. |
| Machine serial number | Which assembly number applies to your build. The same model has been supplied with more than one pump over its production life. |
| Nameplate on a remanufactured unit | That the unit is an exchange assembly, which may carry a different reference from the original. Ask what it was built from. |
How to confirm it
- Read the pump body itself
Photograph the series code and any assembly number stamped on the body. A pump that has already been replaced once may not match the catalog for your machine, and the body is the truth.
- Record the machine model and serial number
Together these place your machine on the correct side of a production break. Where a model has used more than one pump, the serial number is the deciding field, not the model.
- Note the control type
State whether the machine uses negative flow control, positive flow control or load sensing, or simply describe how the machine behaves. A supplier who understands pumps will ask, and answering up front shortens the process.
- List what is being replaced and why
A pump replaced because of gradual wear is a straightforward order. A pump replaced after a failure is a different order, because the circuit needs cleaning and the quote may need filters and strainers alongside it.
- Ask about repair rather than replacement
On larger machines, rebuilding an original pump with a new piston assembly, valve plate, cylinder block and seal kit can be the better value. Whether it is worth doing depends on the state of the housing and shaft, so ask the question explicitly.
- Confirm the grade and warranty on the lines quoted
New, remanufactured exchange and rebuilt-from-core are three different products at three different prices. The quote should say which you are being offered.
What to do about it
If two pump numbers appear on the same machine, do not assume either is wrong. Some builds used different pumps for the two halves of a tandem arrangement, and some used different series across a production break. Send both numbers and the serial number.
Never fit a rebuilt pump into a circuit that has not been cleaned. Metal from the failed pump is distributed through the system, and the fastest way to destroy a replacement is to leave it there.
On a pump that has failed prematurely, check the suction side before fitting the replacement. A collapsed suction hose or a blocked strainer that caused the first failure will cause the second one.
Keep the old pump until the replacement is confirmed working. It is the reference if a question arises, and on a repairable unit it is the core.
Parts you may need, by grade
| Part | Grades commonly quoted |
|---|---|
| Main pump assembly | New; remanufactured exchange where the platform is supported |
| Pump internals kit | Genuine kit; OEM-quality kit, where the housing and shaft are within specification |
| Regulator and control valve | Genuine; OEM-quality, matched to the control type |
| Suction strainer and return filter | Genuine; OEM-quality at the specified micron rating |
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 do I know which pump my machine has?
Read the pump body itself rather than the catalog alone. The stamped series code and assembly number identify the unit fitted, and the machine serial number confirms which assembly the factory specified. Where the pump has been replaced before, the body is more reliable than any list.
Are pump part numbers the same across brands?
The component maker's series code is used across machine brands, but the machine maker's assembly number is specific to how that pump was configured. Two machines from different makers can share a pump series and never share an assembly number.
Can I fit a larger pump for more power?
It is a system change, not a part swap. Flow, relief settings, control type and cooling all have to support it, and the machine's structure and hydraulic components are designed around a specific displacement. Treated as a redesign it can be done; treated as an upgrade it usually causes more problems than it solves.
Do you supply pump parts as well as complete pumps?
Yes. Piston assemblies, valve plates, cylinder blocks, regulators and seal kits are all available in genuine and OEM-quality grades, which is often the better route on a pump whose housing and shaft are still within specification.