The Wacker Neuson Sealing Washer is a genuine OEM sealing washer designed for the APT4S and APT4T pump series. Sourced directly from Wacker Neuson, this part meets the exact material and dimensional standards of the original component installed at the factory. It is confirmed to fit across the APT4S, APT4T, and their Cold Weather variants, making it the correct choice for a wide range of pump configurations in this family. When your pump shows signs of fluid seepage or a worn seal seat, replacing the with a genuine OEM part restores a proper, leak-free connection.
Key Features
- OEM-Grade Seal Material — Manufactured to Wacker Neuson's specified material grade, ensuring the washer compresses and seats correctly to maintain a fluid-tight connection under operating pressure.
- Drop-In Replacement Fit — Matches the original sealing washer profile exactly, seating into the same port or fitting without modification to mating hardware or threads.
- Broad APT Pump Compatibility — Fits the APT4S Pump with Skid, APT4T Pump with Surge Brake, APT4T Pump with Electric Brake, and all corresponding Cold Weather variants.
- Leak Prevention Where It Counts — A correctly seated sealing washer keeps hydraulic or fluid connections properly sealed; a failed or deformed washer leads to fluid loss, pressure drop, and potential pump damage.
- Genuine Wacker Neuson Part — Supplied as authentic OEM stock under part number 5100040905, providing full confidence in part identity and traceability.
A sealing washer creates a compressed, fluid-tight barrier between two mating surfaces — typically at a threaded fitting, port, or bolt connection — preventing fluid from escaping under pressure. In pump applications like the APT4S and APT4T series, these washers are critical to maintaining system integrity and preventing contamination or fluid loss at connection points. When a sealing washer becomes flattened, cracked, or corroded, it loses its ability to compress evenly, leading to leaks that can compromise pump performance and require more extensive repairs if left unaddressed.
Part Details
| Part Number | 5100040905 |
|---|---|
| Brand | Wacker Neuson |
| Part Type | Genuine OEM |
| Description | Sealing Washer |
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.
