The Multiquip 21287 Pump Assembly Tandem Sauer M25 is a genuine OEM hydraulic pump assembly designed for STX55 and HTX44 series Whiteman ride-on power trowels. This direct-replacement assembly restores full hydraulic output to machines including the STX55J6, STX55Y6, STXD6i, HTX44K4, HTX44K5, HTX44Y4, HTX44Y5, and HTXD6i. As a genuine Multiquip OEM component, part 21287 is manufactured to the same specification as the original unit, ensuring correct pressure output, port alignment, and mounting compatibility. When the hydraulic pump on your ride-on trowel begins to fail, blade pitch control and drive performance degrade quickly — restoring it with the correct assembly keeps your machine performing as intended.
Key Features
- Genuine OEM Hydraulic Specification — Built to the same pressure and flow ratings as the original Sauer M25 tandem pump unit, ensuring the hydraulic system operates within its designed parameters.
- Drop-In Assembly Replacement — Supplied as a complete tandem pump assembly with matched porting, so installation aligns directly with the existing hydraulic lines and mounting points on supported trowel models.
- Broad STX55 and HTX44 Series Fitment — Confirmed compatible with STX55J6, STX55Y6, STXD6i, HTX44K4, HTX44K5, HTX44Y4, HTX44Y5, and HTXD6i ride-on power trowels.
- Restores Blade Pitch and Drive Control — The tandem pump simultaneously supplies hydraulic pressure to both the blade pitch and drive circuits; a worn pump causes sluggish or uneven blade response and loss of traction control.
- Hydraulic System Integrity — Using the correct OEM pump assembly prevents pressure imbalances between the two pump circuits that can lead to erratic trowel behavior or accelerated wear on downstream hydraulic components.
The tandem hydraulic pump assembly is the heart of the hydrostatic drive system on Whiteman ride-on trowels. It generates and delivers hydraulic flow to two independent circuits simultaneously — one controlling blade pitch adjustment and one driving machine propulsion — allowing the operator to manage both functions with precision. When this pump loses output pressure due to internal wear or seal failure, the machine may exhibit reduced blade response, poor tracking, or complete loss of drive, making prompt replacement critical to maintaining safe and productive finishing operations.
Part Details
| Part Number | 21287 |
|---|---|
| Brand | Multiquip |
| Part Type | Genuine OEM |
| Description | Pump Assembly Tandem Sauer M25 |
Compatibility & Fitment
| Name | Model |
|---|---|
| Whiteman Ride-On Power Trowels | STX55J6 |
| Whiteman Ride-On Power Trowels | HTX44K4 |
| Whiteman Ride-On Power Trowels | STX55Y6 |
| Whiteman Ride-On Power Trowels | HTXD6i |
| Whiteman Ride-On Power Trowels | STXD6i |
| Whiteman Ride-On Power Trowels | HTX44Y5 |
| Whiteman Ride-On Power Trowels | HTX44Y4 |
| Whiteman Ride-On Power Trowels | HTX44K5 |
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.
