The HM300 (and related HM-series models) is a fully articulated dump truck built for off-highway mining and quarry work — hydraulic power steering with two double-acting cylinders, and a separate hydraulic hoist circuit for the dump body. This is a mining-class machine, not a road tipper truck: if you're looking for a PTO-driven gear pump for an on-road tipper body, see our general Tipper/Dumper page instead, which covers Sauer Danfoss, Eaton, Bosch Rexroth and Parker options for that application.
Komatsu HM-Series — Pump Reference
| System | Function | Reference |
|---|---|---|
| Steering & Hoist Control Pump | Power steering (dual cylinders) plus dump body hoist | Genuine Komatsu part — confirm from nameplate |
| Water Pump (engine cooling) | Engine cooling circuit | Part 6251-61-1100 (HM300-2, for reference) |
Confirm your exact HM-series generation (HM300-1 through -5, or other tonnage class) and pump nameplate before ordering — WhatsApp a photo for a precise match.
What Our Refurbishment Covers
Measured against Komatsu tolerance — critical given the ADT's articulated steering design.
Tested for smooth, reliable dump body lift and lower function.
Replaced as standard on every unit.
Verified at rated pressure with output documented on the written test report.
Why Komatsu HM Owners Choose PumpGrid
Correct Category, Correct Pump
We confirm you need the mining-class ADT pump, not a road tipper gear pump, before quoting — avoiding a costly mismatched order.
40-60% Savings vs New
Refurbishment costs a fraction of new OEM pricing through the dealer channel.
Documented Test Results
Written test report with actual pressure and flow readings.
3-Month Warranty
Replacement, not repair, if a refurbishment defect appears within warranty.