The Wacker Neuson Oil Seal is a genuine OEM component designed for the APT4S and APT4T pump series, including standard, surge brake, electric brake, and cold weather variants. As a direct OEM replacement, this seal is manufactured to the same specifications as the original part — ensuring a consistent, like-for-like fit within the pump assembly. It is compatible across the full APT4S and APT4T lineup, covering both skid-mounted and cold weather configurations. Keep a spare on hand to minimize unplanned service interruptions during critical pump operations.
Key Features
- OEM-Grade Sealing Material — Manufactured to original Wacker Neuson specifications, delivering the same compression characteristics and fluid resistance as the factory-installed seal.
- Drop-In Pump Fit — Engineered to seat correctly within the APT4S and APT4T pump housings without reworking or shimming the installation point.
- Broad APT Series Coverage — Fits APT4S Pump with Skid, APT4T Pump with Surge Brake, APT4T Pump with Electric Brake, and all corresponding Cold Weather variants in a single part number.
- Leak Prevention at the Source — A properly functioning oil seal keeps lubricant inside the pump and contaminants out, preserving internal bearing and shaft surfaces from premature wear.
- Fluid Containment Safety — A failed or worn oil seal can allow oil to migrate toward brake components on surge and electric brake models, making prompt seal replacement critical on brake-equipped configurations.
An oil seal creates a dynamic barrier between rotating shaft surfaces and the surrounding pump housing, retaining lubricating oil while blocking dirt, water, and debris from entering the assembly. Without an intact seal, oil migrates out of the pump, lubricant levels drop, and internal components — including bearings and the drive shaft — begin to run dry and wear rapidly. On brake-equipped pump models, oil contamination can also compromise brake performance, making timely seal replacement an important part of routine pump maintenance.
Part Details
| Part Number | 5200019851 |
|---|---|
| Brand | Wacker Neuson |
| Part Type | Genuine OEM |
| Description | Oil 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.
