The Wacker Neuson 5200020171 is a genuine OEM O-Ring designed for the APT4S and APT4T series self-priming pumps, including cold weather and standard configurations with surge brake and electric brake variants. As a factory-sourced component, the 5200020171 is manufactured to the exact material and dimensional specifications required to maintain a proper fluid-tight seal within these pump assemblies. Confirmed fitment spans the full APT4S and APT4T lineup, covering skid-mounted and trailer-mounted configurations across both standard and cold weather builds. Keep a spare on hand — O-Ring replacement is a routine part of pump maintenance, and having the correct Wacker Neuson part on site keeps service intervals fast and straightforward.
Key Features
- Genuine OEM Seal Material — Factory-sourced compound ensures the correct durometer and chemical resistance for pump fluid contact and pressure cycling in the APT series.
- Drop-In Replacement — Dimensionally identical to the original, seating into the same groove geometry without trimming, stretching, or modification.
- Broad APT4 Series Coverage — Fits APT4S Pump with Skid, APT4T Pump with Surge Brake, and APT4T Pump with Electric Brake, in both standard and cold weather variants.
- Maintains Pump Prime and Output — A correctly seated O-Ring prevents air ingestion and pressure loss that would cause the pump to lose prime, cavitate, or deliver reduced flow.
- Leak Prevention at the Source — A degraded or improperly sized O-Ring in a pump assembly can result in fluid leaks and loss of suction head; using the correct OEM part eliminates that risk.
An O-Ring is a precision sealing element that sits within a machined groove to create a compression-based fluid-tight barrier between mating pump components. In a self-priming pump like the APT4S and APT4T, O-Rings are critical to holding suction pressure and preventing air from entering the pump housing — both of which are essential for the pump to prime and sustain flow. When an O-Ring ages, dries out, or is damaged during service, the seal degrades, resulting in air leaks, lost prime, or external fluid weeping that reduces pump efficiency and can lead to further component wear.
Part Details
| Part Number | 5200020171 |
|---|---|
| Brand | Wacker Neuson |
| Part Type | Genuine OEM |
| Description | O-Ring |
Compatibility & Fitment
| Name | Model | Machine Number |
|---|---|---|
| APT4S Pump w/Skid, Cold Weather | APT4S CW | 5200019798 |
| APT4T Pump, Electric Brake, Cold Weather | APT4T CW | 5200019793, 5200019792 |
| APT4T Pump, Surge Brake | APT4T | 5200019643, 5200019644 |
| APT4S Pump w/Skid | APT4S | 5200018977 |
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.
