The Wacker Neuson Piston Pin is a genuine OEM component designed for the APT4S and APT4T pump series, including standard, surge brake, electric brake, and cold weather configurations. As a factory-sourced part, it is manufactured to the same specifications as the original, ensuring a direct fit within the pump's reciprocating assembly. Compatible across six APT4S and APT4T model variants, part number covers a broad range of diaphragm pump applications in a single replacement part. Keep this pin on hand as a service spare to maintain full pump output and avoid unplanned stoppages on the job.
Key Features
- Hardened to OEM Dimensional Tolerance — Manufactured to the exact diameter and surface finish required for proper pin-to-piston fit, preventing side-play and premature bore wear.
- Drop-In Replacement — Aligns directly with the existing piston bore and retaining clips in APT4S and APT4T pump assemblies, requiring no machining or fitting adjustments.
- Broad APT Series Coverage — Fits APT4S (with skid) and APT4T (surge brake, electric brake) models, including all cold weather variants, under a single part number.
- Sustained Pump Output — A correctly fitted piston pin maintains consistent stroke geometry, preserving full flow rate and discharge pressure across the pump's operating range.
- Genuine Wacker Neuson OEM Part — Sourced directly through the Wacker Neuson parts program, so you receive the same component originally installed at the factory.
The piston pin is a precision cylindrical fastener that connects the connecting rod to the piston within a reciprocating pump assembly. It transfers the mechanical force of the drive stroke directly into piston movement, making it central to the pump's ability to build and sustain pressure. When a piston pin wears, becomes loose, or fails, the piston loses its alignment, leading to reduced flow, increased internal wear, and eventual pump failure.
Part Details
| Part Number | 5200020046 |
|---|---|
| Brand | Wacker Neuson |
| Part Type | Genuine OEM |
| Description | Piston Pin |
Compatibility & Fitment
| Name | Model | Machine Number |
|---|---|---|
| APT4S Pump w/Skid | APT4S | 5200018977 |
| APT4T Pump, Surge Brake | APT4T | 5200019643, 5200019644 |
| APT4T Pump, Surge Brake, Cold Weather | APT4T CW | 5200019792, 5200019793 |
| APT4S Pump w/Skid, Cold Weather | APT4S CW | 5200019798 |
Verify Before You Order
Fitment is machine-number and revision-specific; always confirm your model and serial number against the fitment list.
Why Buy From DHS Equipment
Every part is verified against the manufacturer's part number before it ships, so what you order is what arrives. We carry parts from leading OEM brands and our own DHS Quality Parts line of professional aftermarket components. Need help finding the right part? Our team is available to confirm compatibility whenever you need it. Orders are processed fast to keep your jobs on track. We don't just sell parts. We keep you jobsite ready.
Questions? Contact our team at [email protected] or 866-611-9369 — DHS Equipment is here to help you maintain peak performance.
