The Wacker Neuson 5200019890 is a genuine OEM Rocker Arm designed for the APT4T and APT4S series self-priming pumps. This part covers a broad range of configurations including surge brake, electric brake, and cold weather variants across both the APT4T and APT4S pump families. As a direct OEM replacement, the 5200019890 is manufactured to the same specifications as the original component installed at the factory, ensuring proper fit and correct mechanical function. Compatible models include the APT4T Pump with Surge Brake, APT4T Pump with Electric Brake, APT4S Pump with Skid, and all corresponding cold weather variants.
Key Features
- Genuine OEM Pivot Geometry — Manufactured to exact pivot-point and contact-surface specifications, maintaining the correct valve actuation stroke for this pump engine's valve train.
- Drop-In Engine Valve Train Replacement — Installs directly onto the original rocker shaft and seat without machining or shimming, preserving correct valve clearance settings.
- Broad APT4T and APT4S Coverage — A single part number services surge brake, electric brake, and cold weather pump configurations, simplifying parts procurement across your fleet.
- Sustained Pump Output — A properly functioning rocker arm ensures full valve lift and accurate timing, which directly supports consistent engine power and pump discharge performance.
- Wear-Critical Component — The rocker arm contact pad is subject to continuous friction; a worn or cracked rocker arm causes valve float, rough running, and loss of prime in pump operation.
The rocker arm is a pivoting lever in the engine's valve train that transfers motion from the camshaft — via the pushrod — to open and close the intake and exhaust valves. It sits on a rocker shaft or stud above the cylinder head and rocks back and forth with each engine revolution, precisely timing valve events to the piston cycle. When a rocker arm wears at its contact pad or cracks at its body, valve lift becomes inconsistent, leading to rough idle, reduced power output, and in pump applications, difficulty maintaining prime or achieving full discharge flow. Replacing a worn rocker arm restores correct valve timing and keeps the engine running at the power level the pump demands.
Part Details
| Part Number | 5200019890 |
|---|---|
| Brand | Wacker Neuson |
| Part Type | Genuine OEM |
| Description | Rocker Arm |
Compatibility & Fitment
| Name | Model | Machine Number |
|---|---|---|
| APT4T Pump, Surge Brake | APT4T | 5200019643, 5200019644 |
| APT4T Pump, Surge Brake, Cold Weather | APT4T CW | 5200019792, 5200019793 |
| APT4S Pump w/Skid | APT4S | 5200018977 |
| 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.
