Genuine Kubota Common Rail Assembly 1J508-50602 | V3800 Fuel Rail

Kubota part number 1J508-50602 is the genuine common rail assembly (Kubota catalog listing “RAIL,ASSY”) for the V3800 common rail diesel engine. The rail is the high pressure accumulator at the heart of the fuel system. It stores fuel delivered by the supply pump at extremely high pressure and feeds each injector on demand, so a cracked, eroded, or leaking rail shows up fast as hard starting, low rail pressure fault codes, external fuel leaks, or a machine stuck in derate or limp mode. This is the current Kubota part number and it supersedes the earlier rail 1J508-50600. Valley Fuel Injection & Turbo is an authorized Kubota dealer, and this rail ships as a new genuine Kubota part through our Kubota engine sales, parts, and service department.

Application & Fitment

Engines:

• Kubota V3800 common rail diesel (Tier 4 Final family)

Equipment:

• Kubota SVL95-2S and SVL95-2SC compact track loaders
• Kubota SVL97-2 and SVL97-2C compact track loaders
• Kubota M5 series tractors, including M5-091HD and M5-111HD models
• Kubota M5N and M6S series tractors

Kubota has used more than one rail part number across V3800 production, so send us your engine model and engine serial number and we will verify the exact rail for your machine before anything ships.

Cross-Reference Part Numbers

• Kubota 1J508-50600 | earlier part number, superseded by 1J508-50602
• Denso 095600-5701 | Denso rail number widely referenced for this assembly

If your parts book or old rail shows 1J508-50600, this is the correct current genuine replacement. If you are matching a Denso number stamped on the rail itself, call us with your engine serial number and we will confirm the match before you order.

Frequently Asked Questions

Does 1J508-50602 replace the older 1J508-50600 rail?

Yes. Kubota superseded 1J508-50600 to 1J508-50602, and this is the direct factory replacement. Order this number even if your parts book or the tag on your old rail shows 1J508-50600.

Will a new rail fix my low rail pressure or limp mode problem?

Sometimes, but not always. Low rail pressure on a V3800 can also come from the supply pump, the rail pressure sensor, the pressure limiter, injector back leakage, or a restricted fuel supply, and a new rail will not cure those. Our shop diagnoses and repairs these systems every day. If you are chasing a pressure code, read about our common rail system repair services or call us before you buy and we will help you pin down the real cause.

Is this a genuine Kubota part?

Yes. Valley Fuel Injection is an authorized Kubota dealer, and 1J508-50602 ships as a new genuine Kubota rail assembly in Kubota packaging. On a component that holds fuel at extremely high pressure, we do not recommend gambling on an untested copy.

Why Buy From Valley Fuel Injection?

Valley Fuel Injection & Turbo has specialized in diesel fuel injection since 1993 from our shop in Woodland, California. We are an authorized Kubota dealer backed by a working diesel fuel injection service department, which means the people selling you this rail also test pumps, injectors, and complete common rail systems on the bench every day. You get a genuine part, real fitment verification against your serial number, and straight answers if the rail turns out not to be your problem.

Pricing and Availability

Call 530-668-0818 for current pricing and availability on the genuine Kubota 1J508-50602 common rail assembly, or reach us through our contact page. Please have your engine model and engine serial number ready so we can confirm the correct rail for your machine before it ships.