The Wacker Neuson Seal is a genuine OEM Seal designed for the APT4S and APT4T pump series, including standard and Cold Weather configurations. As a factory-sourced component, this seal is manufactured to the exact material grade and dimensional tolerances specified by Wacker Neuson, ensuring a proper fit within the pump assembly. It covers the full range of APT4S and APT4T variants — Surge Brake, Electric Brake, Pump with Skid, and Cold Weather models — making it the correct choice across the entire pump family. When you need a direct OEM replacement, part number is the verified solution.
Key Features
- OEM-Grade Seal Material — Manufactured to Wacker Neuson's specified compression and material standards, delivering the sealing performance the pump was engineered around.
- Drop-In Fitment — Matches the original seal profile exactly, seating into the pump housing without modification or rework to surrounding components.
- Broad APT Series Coverage — Fits APT4S (Pump with Skid) and APT4T (Surge Brake and Electric Brake) models, including Cold Weather variants, across the full pump lineup.
- Leak Prevention Where It Counts — A properly seated seal keeps fluid contained within the pump circuit; a worn or failed seal leads to fluid loss, pressure drop, and accelerated pump wear.
- Genuine Wacker Neuson Part — Sourced directly from Wacker Neuson, so the part number, geometry, and material spec match the original component your pump left the factory with.
A seal in a pump assembly creates a fluid-tight barrier between moving and stationary components, preventing internal or external fluid leakage under operating pressure. In trailer-mounted pumps like the APT4S and APT4T, maintaining an intact seal is critical to sustaining consistent flow and pressure throughout the pump cycle. When a seal degrades — through wear, chemical exposure, or compression set — fluid bypasses the barrier, leading to loss of output pressure, visible leaks, and potential damage to adjacent pump components if left unaddressed.
Part Details
| Part Number | 5200021709 |
|---|---|
| Brand | Wacker Neuson |
| Part Type | Genuine OEM |
| Description | Seal |
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.
