This is the Bosch-boxed version of Kubota 1J801-53052. Bosch 0445110777 is the same new, genuine Bosch common-rail injector that Kubota sells in its own packaging. It fits the Kubota D1803-CR 3-cylinder and V2403-CR 4-cylinder common-rail engines, including the D1803-CR-E4, D1803-CR-TE4, V2403-CR-E4 and V2403-CR-TE4. That covers the Kubota L, MX and M5660SU tractors listed below, the L47 loader backhoe, and the KX040-4, KX040-5 and U48-5 excavators.

Kubota 1J801-53052 replaces the earlier 1J801-53050, so either Kubota number points to this injector. Common reasons to replace: hard starting, rough idle, smoke, misfire or injector fault codes, and low power. The turbo-intercooled TIE4 versions of these engines take a different injector (Kubota 1J808-53052, Bosch 0445110775), so read the engine plate before you order.

Specifications

Fits / Applications

• Kubota D1803-CR-E4 and D1803-CR-TE4 3-cylinder common-rail engines
• Kubota V2403-CR-E4 and V2403-CR-TE4 4-cylinder common-rail engines
• Kubota KX040-4, KX040-5 and U48-5 excavators
• Kubota L3301, L3302, L3901, L3902 and L4701 tractors
• Kubota L3560, L4060, L4760, L5060, L5460 and L6060 tractors
• Kubota MX4800, MX5200, MX5400, MX5800 and MX6000 tractors
• Kubota M5660SU tractor
• Kubota L47 tractor loader backhoe

Each injector carries its own compensation (correction) value. Kubota’s D1803-CR / V2403-CR workshop manual says to register the new injector’s compensation value to the engine ECU with Kubota Diagmaster after replacement, with the engine stopped and the key switch on. Write down each code and its cylinder before you install. Fit new seals, clean the injector bore, change the fuel filter and drain the water separator.

Part Numbers & Cross Reference

Kubota (same injector in Kubota packaging) 1J801-53052  ·  Kubota (earlier, replaced by 1J801-53052) 1J801-53050  ·  Kubota (earlier, listed as interchange) 1J801-53051  ·  Bosch (earlier number, listed as equivalent) 0445110505

Cross-reference numbers can change with engine serial, build year and emissions tier, so treat this list as a starting point. Send us your engine serial number and we will confirm the exact match against your build before anything ships. That check is free and takes a few minutes.

Why Buy From Valley Fuel Injection

We are a diesel fuel-injection and turbocharger shop in Woodland, CA, rebuilding pumps, injectors and turbos on our own benches since 1993, not a drop-ship storefront. When you call, you talk to the people who test these units. We verify fitment against your engine serial, VIN or build date before anything ships, so the right part arrives the first time.

Not sure the injectors are the problem? We test and diagnose in-house before you buy. See our common rail injector testing and rebuild service.