Hydraulic pumps drive the muscle of a machine, and a failed one stops everything. The stamped model number is the fast path, but when it's worn off you can still identify a pump from its physical characteristics. Here's what matters.
Pump type
- Gear pump: simple, economical, fixed displacement — common on mobile equipment.
- Vane pump: smooth and quiet, fixed or variable.
- Piston pump (axial/radial): high pressure and efficiency, often variable displacement.
The numbers that define it
- Displacement: volume per revolution (cc/rev or in³/rev) — sets the flow.
- Max pressure rating (bar or psi).
- Rotation: clockwise or counter-clockwise (viewed from the shaft end) — get this wrong and it won't pump.
Mechanical interfaces — must match exactly
- Shaft: keyed, straight, tapered, or splined (and the spline count).
- Mounting flange: SAE A/B/C/D 2- or 4-bolt, or an ISO/metric flange.
- Ports: size and type (SAE O-ring, BSP, NPT, or flange), and their location.
Match function over brand
Pumps from Parker, Bosch Rexroth, Eaton/Vickers, Danfoss (Sauer-Danfoss) and Casappa often have direct equivalents when displacement, pressure, rotation, shaft and mounting match. Send us the model number or a photo plus the shaft/flange details, and we'll identify and quote a replacement.