The Wacker Neuson Piston Ring Set is a genuine OEM Piston Ring Set designed for the APT4S and APT4T series pumps, including standard, surge brake, electric brake, and cold weather configurations. As a direct Wacker Neuson OEM part, the is manufactured to the same specifications as the original component installed at the factory, ensuring a proper fit across all covered models. This set covers a broad range of APT4 pump variants — including cold weather builds — making it the correct choice whether you're servicing a standard skid unit or a surge or electric brake configuration. Keep part number on hand for planned maintenance or as a critical rebuild component when wear is detected.
Key Features
- OEM Ring Geometry and Tolerancing — Manufactured to Wacker Neuson's original bore diameter and ring thickness specs, ensuring correct compression and oil control for this pump's cylinder assembly.
- Drop-In Cylinder Replacement — Sized to install directly into the original cylinder bore without machining or modification, aligning with existing ring grooves on the OEM piston.
- Broad APT4 Series Coverage — Fits APT4S and APT4T pump models across surge brake, electric brake, and cold weather variants, consolidating one part number across your APT4 fleet.
- Restores Compression and Pump Output — Worn or broken piston rings allow blow-by that robs the pump of compression and drive efficiency; a fresh ring set brings output back to original operating levels.
- Genuine Wacker Neuson OEM Part — Sourced directly through Wacker Neuson's authorized parts network, carrying the correct part number 5200020045 for confident identification and procurement.
Piston rings seal the gap between the piston and the cylinder wall, maintaining the compression needed to drive the pump's internal mechanism efficiently. They also regulate oil consumption by preventing excess oil from entering the combustion or compression chamber. When rings wear, crack, or lose tension, compression drops, performance suffers, and oil consumption increases — symptoms that typically worsen quickly if the rings are not replaced during routine service.
Part Details
| Part Number | 5200020045 |
|---|---|
| Brand | Wacker Neuson |
| Part Type | Genuine OEM |
| Description | Piston Ring Set |
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.
