Kubota 1J574-50504 High-Pressure Supply Pump for V3800 Common-Rail Engines

The Kubota 1J574-50504 (Kubota catalog description: ASSY PUMP,SUPPLY) is the genuine Denso-built high-pressure common-rail supply pump for Kubota’s V3800 diesel. It is the current revision in the 1J574-50500 pump family and the component that builds rail pressure for the injectors on common-rail V3800DI-T and V3800-TI-CRS engines, found in Kubota M96S, M108S, M100X and M110X tractors. Hard starting, low rail-pressure codes, loss of power and stalling under load are the classic signs of a worn supply pump, and this genuine assembly is the factory-correct fix.

Application & Fitment

• Engines: Kubota V3800DI-T common-rail variants (often listed simply as V3800DI or V3800) and the V3800-TI-CRS common-rail turbo (2009-2014)
• Kubota M108S tractor (confirmed application)
• Kubota M96S tractor (listed for the same 1J574-505xx pump family)
• Kubota M100X / M100XDTC tractor
• Kubota M110X / M110XDTC tractor

Aftermarket references also list Japan-market M108 variants (M108DSC, M108SDS, M108SH, M108XDTC and related models). Call us to verify those against your serial number.

Important: later Tier 4 V3800-CR engines, such as those in SVL90-2 and SVL95-2s track loaders, use a different 1J500-series pump (Denso 294000-1720/1730). Those numbers do not interchange with 1J574-50504, so confirm your engine model and serial number before ordering.

Cross-Reference Part Numbers

• Denso 294000-0690, 294000-0691, 294000-0692, 294000-0693
• Kubota 1J574-50500, 1J574-50501, 1J574-50502, 1J574-50503 (earlier revisions superseded by 1J574-50504)
• Kubota KEARP-1J574 (Kubota remanufactured exchange number)

Frequently Asked Questions

Will 1J574-50504 fit my tractor?

If your machine currently runs an earlier revision (1J574-50500 through 1J574-50503) or a pump marked Denso 294000-0690 through 294000-0693, 1J574-50504 is the current genuine replacement. It serves common-rail V3800DI-T and V3800-TI-CRS engines in the M96S, M108S, M100X and M110X tractor families. Have your engine model and serial number ready and we will confirm the exact part before you buy.

Why buy a genuine Kubota pump instead of an aftermarket copy?

This is a Denso HP3-type common-rail pump running extremely tight internal clearances at injection pressure. A genuine Kubota assembly is built and calibrated to Denso and Kubota specification and carries dealer warranty support. Cheap copies of this part number are common online, and a pump that sheds metal can take the injectors and rail down with it, turning one repair into a full fuel-system job.

How do I order this pump?

Call 530-668-0818 or request a quote online. The pump is supplied to order through our Kubota dealer parts network, and we will quote current pricing, availability and lead time. If your original pump failed with debris in the fuel, ask us about testing or rebuilding the rest of your common-rail system in-house at the same time.

Why source your Kubota parts from Valley Fuel Injection

As an authorized Kubota dealer and diesel fuel-injection specialists, Valley Fuel Injection & Turbo supplies genuine Kubota engines and fuel-system components, and we rebuild the very common-rail systems these parts serve. Diesel is all we do, and we have done it across Northern California and Nevada since 1993.

Pricing & availability: this genuine Kubota high-pressure supply pump is supplied to order. Call 530-668-0818 or request a quote for current pricing, availability and lead time. Have your engine model and serial number ready so we can confirm the exact part for your machine.

Why do I see this pump cheaper online?
Short answer: it is usually not the same part — and a pump failure does not stay in the pump. Read why ↓

Search any OE number and eBay, Amazon and a dozen storefronts will show it well under dealer cost, sold by outfits with no name, no address and no phone number. We lose business to those listings every week — and we see a lot of them come back through our shop. Here is what is actually different.

• The part number proves nothing on its own. Counterfeit injectors and pumps are stamped with the same OE numbers as the real thing, in housings cast to look identical. The number in the listing title tells you what the seller claims it is, not what came off an OE line.
• “Remanufactured” is not a regulated word. A genuine reman unit is stripped to bare components, has its wear parts replaced — nozzle, plunger and barrel, solenoid, seals — and is then run on a calibration bench until it meets the original flow and response spec. A cheap one is very often cleaned, resealed, painted and shipped. Both get called remanufactured.
• No full teardown, so no idea what is worn. A proper rebuild means the unit comes apart completely and every part gets inspected and measured against spec — not just the ones that are obviously bad. Skip the teardown and you are reusing worn internals inside a freshly painted housing. It will run on the truck. It will not last.
• No factory-spec bench load testing. A unit is not finished until it has been run under load on a test bench and made its numbers across the range, not just at one easy point. That bench time is most of what you are paying for. Sellers working on price cut it first, because nobody can see it in a photo.
• The warranty has to be honored by someone. Everything we remanufacture in house carries a one-year warranty, with 30 days on electrical components. Parts we supply as an authorized dealer carry the manufacturer’s own warranty. Either way you call us, a real shop in California, and we sort it out. A marketplace warranty usually means shipping the part overseas at your own cost and hoping for a reply.
• No core program. We credit your rebuildable core back in full. Discount sellers generally will not take one, so the gap narrows the moment you account for the core you are now stuck holding.
• A pump failure does not stay in the pump. When a high-pressure pump comes apart it sends metal downstream through the rails, the lines and every injector. That is the whole reason fuel contamination kits exist. A pump that was never tested to spec is the cheapest possible way to buy that repair.

We are an authorized dealer and a working fuel-injection shop — we have been rebuilding and testing this hardware in Woodland since 1993, and the people who answer the phone are the people who run the benches. Not sure this is the right part for your engine? Call us with your serial number before you order and we will confirm it. Send your rebuildable core back and the core charge is refunded. And if a price somewhere else looks too good, call 530-668-0818 and we will tell you straight whether it is a deal or a problem.