This is a new, genuine Bosch CP4.1 high-pressure common-rail fuel pump, Bosch 0445020538. It fits Yanmar TNV common-rail engines: the 3TNV86CT, 3TNV88C, 4TNV86CT, 4TNV88C, 4TNV98C and 4TNV98CT. It replaces the earlier Bosch 0445020509 and matches Yanmar 129C28-51000 (earlier 129A00-51000). John Deere (MIA885077, MIA881999) and Bobcat (7029317) list it under their own numbers.

The CP4.1 has one pumping piston and is lubricated only by fuel. Water, air in the fuel and dirty fuel are the main enemies of any CP4. Hard starting, low rail pressure codes and loss of power are common signs of a worn pump. If the old pump made metal, clean or replace the rail, lines and injectors before the new pump goes in.

Specifications

Fits / Applications

• Yanmar 3TNV86CT
• Yanmar 3TNV88C
• Yanmar 4TNV86CT
• Yanmar 4TNV88C
• Yanmar 4TNV98C
• Yanmar 4TNV98CT
• John Deere and Bobcat equipment with these Yanmar common-rail engines (OE numbers MIA885077 / MIA881999, 7029317)

The CP4.1 is lubricated only by diesel fuel. Find the cause of the old pump failure first. If the old pump made metal, clean or replace the rail, lines and injectors. Fit new fuel filters, drain the water separator, fix any suction-side air leaks and prime the system per the Yanmar or equipment procedure. Compare the connectors and sensors on your old pump with the new one before you install it.

Part Numbers & Cross Reference

Bosch (superseded) 0445020509  ·  Yanmar 129C28-51000  ·  Yanmar (earlier) 129A00-51000  ·  John Deere MIA885077  ·  John Deere MIA881999  ·  Bobcat 7029317

Send us your engine serial number and we will help you confirm the exact match against your build before you order. That check is free and takes a few minutes.

Frequently Asked Questions

Which Yanmar engines does Bosch 0445020538 fit?

It fits the Yanmar 3TNV86CT, 3TNV88C, 4TNV86CT, 4TNV88C, 4TNV98C and 4TNV98CT. This pump is listed only for TNV engines with a C in the model.

My old pump is marked 0445020509 or 129A00-51000. Is 0445020538 the replacement?

Yes. Bosch 0445020509 and Yanmar 129A00-51000 are the older numbers this pump replaces. The current Yanmar number is 129C28-51000.

Does 0445020538 cross to John Deere or Bobcat numbers?

Yes. John Deere lists it as MIA885077 and MIA881999 and Bobcat as 7029317. Call 530-668-0818 with the machine make, model and serial, or the engine model and serial from the Yanmar plate, and we confirm the match at no charge before anything ships.

Is 0445020538 new, and do I send my old CP4.1 back?

It is a new, genuine Bosch CP4.1 in original packaging. There is no core charge, so the old pump stays with you.

Related Parts

• Yanmar 3TNV88C & 4TNV88C Common-Rail High-Pressure Pipe, Rail In | Yanmar 129A00-59700 New
• Yanmar 129A00-53100 New Common-Rail Injector | 3TNV88C & 4TNV88C
• Yanmar 129A00-53100 New Common-Rail Injector Set of 4 | 3TNV88C & 4TNV88C
• Yanmar 4TNV98CT 3.3L Common-Rail Fuel Injector | Bosch 0445110508 New (Yanmar 129E01-53100)
• Yanmar & Thermo King Reefer Common-Rail Fuel Injector (Yanmar 129C28-53100) | Bosch 0445110679 New

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 run our test benches. Confirm fitment with your engine serial number, VIN or build date before you order, and call us if you want help checking it, so the right part arrives the first time.