705-22-28320 Gear Pump for Komatsu HD785 and HD785-7 Mining Dump Trucks
This gear pump is a replacement unit for part number 705-22-28320, used on the Komatsu HD785 and HD785-7 mining dump trucks. It is an external gear pump with a cast iron body and hardened steel gears, built to keep steady oil flow on haul trucks that run loaded shifts around the clock on mine haul roads. The mounting flange and shaft match the original pump position, so the unit is a direct swap during a service stop.
Pump Specifications
| Item | Detail |
|---|
| Part number | 705-22-28320 |
| Part name | Hydraulic gear pump / gear oil pump assembly |
| Pump type | External gear pump |
| Body material | Cast iron housing |
| Gear material | Hardened and ground steel gears |
| Application | Komatsu HD785, HD785-7 mining dump trucks |
| Condition | New aftermarket replacement, flow and pressure tested |
| Packing | Anti-rust film, foam, export carton or wooden case |
Why This Pump Suits Mining Haul Trucks
- Hardened and ground gears — tooth surfaces resist wear and scoring, so flow stays stable instead of falling off as the pump ages
- Cast iron body — keeps its shape and clearances under continuous high pressure and vibration on haul roads
- Tested before packing — every pump is run and checked for flow, pressure and noise, so a weak unit does not reach your workshop
- Direct fitment — flange, shaft and port positions match the original 705-22-28320 unit, no adapter or machining needed
- Seal kit matched — lip seals and O-rings are supplied fitted, which is where most old pumps start leaking
Typical Symptoms This Pump Fixes
- Slow hoist or steering response when the truck is loaded
- Whining or knocking noise from the pump area
- Oil leaking at the pump shaft seal or flange joint
- Oil overheating and flow dropping after a few hours of work
- Metal particles found in the hydraulic oil or filter
Installation Notes
- Confirm the machine plate reads HD785 or HD785-7 and the old pump is marked 705-22-28320 before ordering; send us photos of the old nameplate if the serial range is unclear
- Drain and flush the circuit, and replace the suction filter and return filter at the same time
- Fill the pump case with clean hydraulic oil before first start to avoid a dry run
- Check relief valve setting and coupling alignment; a misaligned coupling is the most common cause of a repeat shaft seal failure
- Run at low idle for a few minutes, check for leaks, then load the circuit and recheck oil level
Packing and Shipping
Each pump is drained, plugged, wrapped in anti-rust film and shock absorbing foam, then packed in an export carton or wooden case depending on quantity. We supply packing photos, packing list and commercial invoice before dispatch, and can ship by express, air or sea.
FAQ
Q: Is this a genuine Komatsu part?
A: It is a new aftermarket replacement unit built to fit the 705-22-28320 position, priced well below dealer parts while keeping the same mounting dimensions and port layout.
Q: Does it fit both HD785 and HD785-7?
A: Yes, both models use this pump position. If your truck is another HD series model, send the part number from the old pump and we will confirm the match.
Q: What is the minimum order quantity?
A: One piece is acceptable for a trial order, and we offer better pricing for fleet maintenance buyers and repair workshops ordering in batches.
Q: How long is the lead time?
A: Usually 3 to 7 working days for stock units, and 15 to 25 days for production orders, depending on quantity.
Q: Can you supply the seal kit together with the pump?
A: Yes. Seal kits, couplings and filters for the same service can be added to the same shipment so one delivery covers the full repair.
Regional Buyer FAQ
North America and Europe
Q: Do you supply CE or EPA documents?
A: The pump is a replacement component, not a CE-marked machine, so machine-level CE or EPA certificates do not apply. We can provide material certificates, test reports and the commercial documents your customs broker requires.
Q: How is the shipment packed for import clearance?
A: Small orders travel in export cartons, larger orders in heat treated ISPM 15 marked wooden cases, and we send packing photos and the packing list before dispatch.
Middle East and Gulf
Q: Will the pump handle high ambient temperature and dust?
A: The cast iron body and hardened gears tolerate hot, dusty haul road duty. We recommend the correct oil viscosity grade for ambient above 45 C and filter changes at every 500 hours.
Q: Do you accept L/C for fleet orders?
A: Yes, we work on T/T and L/C, and repeat fleet buyers can be supplied against a rolling delivery schedule.
Southeast Asia
Q: How do you prevent rust during sea freight?
A: Pumps are drained, plugged and wrapped in anti-rust film before foam packing, which suits humid destinations. Desiccant bags can be added on request.
Q: Can I combine this pump with other parts in one shipment?
A: Yes, gear pumps, swing motors and travel motors are frequently shipped together by LCL to save freight.
South America
Q: Is the pump suitable for high altitude mines?
A: The pump is mechanically driven and does not lose displacement with altitude. Confirm oil viscosity and relief pressure setting on machines working above 3000 m.
Q: Can you provide Spanish documents?
A: Yes, packing list, invoice and installation notes can be issued in Spanish on request.
Africa
Q: Our workshop has limited tooling, is the swap simple?
A: The flange, shaft and ports match the original position, so it is a bolt-on change. We supply a step-by-step installation note and can send photos of the mounting face before shipping.
Q: Can you include the common wear parts in the same case?
A: Yes, seal kits, filters and couplings are often added so one shipment covers the whole repair.
Russia and CIS
Q: How does the pump behave in low temperature?
A: Cold start performance depends on the oil grade. We mark the recommended viscosity on the packing note and can supply low temperature seals for machines working below -25 C.
Q: Which documents are provided for customs?
A: Commercial invoice, packing list, certificate of origin on request, and a technical description sheet so the goods are classified correctly at import.
About Us
We focus on after-market hydraulic maintenance and replacement parts for construction machinery, covering hydraulic pumps, travel motors, swing motors, control valves, gear pumps and related gearbox components for excavators, mining dump trucks, rotary drilling rigs, pile drivers, concrete mixers, pump trucks, cranes and harvesters. Our workshop supplies both single-part repair orders and full overhaul kits.
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