The Wacker Neuson 5200021689 is a genuine OEM O-Ring designed for the APT4S and APT4T series self-priming pumps. This includes standard and cold weather configurations across the APT4S Pump with Skid, APT4T Pump with Surge Brake, and APT4T Pump with Electric Brake variants. As a factory-sourced component, the 5200021689 meets the exact material and dimensional specifications set by Wacker Neuson for these pump families. Keeping the sealing system in good condition is essential to maintaining pump performance and preventing fluid loss at critical connection points.
Key Features
- Genuine OEM Sealing Material — Factory-sourced elastomer compound matched to the pressure and fluid compatibility requirements of the APT4S and APT4T pump systems.
- Exact Dimensional Fit — Sized to the original groove and port specifications, ensuring full compression and a leak-free seal upon installation without rework.
- Broad APT4 Series Coverage — Compatible with APT4S Pump with Skid, APT4T Pump with Surge Brake, APT4T Pump with Electric Brake, and all corresponding cold weather variants.
- Maintains Pump Integrity — A correctly seated O-Ring prevents air ingestion and fluid bypass that would cause loss of prime, reduced flow, and pump cavitation.
- Cold Weather Configuration Ready — Verified fitment for cold weather APT4S and APT4T models, ensuring the seal performs across the full operating temperature range these machines are built for.
An O-Ring provides a static or dynamic seal between two mating surfaces or components within the pump assembly. In a self-priming pump like the APT4S and APT4T, O-Rings prevent air from entering the fluid path and stop pressurized liquid from escaping at connection points, housings, or valve interfaces. When an O-Ring becomes cracked, compressed flat, or chemically degraded, it loses its ability to hold a seal — leading to loss of prime, visible leaks, or a drop in discharge pressure that signals immediate attention is needed.
Part Details
| Part Number | 5200021689 |
|---|---|
| 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.
