The Caterpillar 4255421 seawater pump is replaced by the JMP JPR-CT0440 pump, also compatible with Jabsco 29630-1201 and Perkins W100006 models.
The JMP JPR-CT0440 seawater pump is a direct replacement for Caterpillar 4255421, Jabsco 29630-1201, and Perkins W100006 pumps used on Caterpillar C4.4 and Perkins M92B engines.
Designed for professional marine applications, it ensures reliable cooling, long service life, and consistent performance even under demanding operating conditions.
| Impeller | JMP 7400K |
| Minor Repair Kit | JSM0143 |
| Service Kit | JSK0143 |
More Technical Specifications:
| Weight | 4,0 kg |
| Ports Type | |
| Materials | |
| Body | Heavy Duty Marine Grade Casting |
| Shaft | Marine Grade Shaft (3X Series Non-Magnetic) |
| Seal | Mechanical |
| Maker | Codes |
| Caterpillar | 4255421 425-5421 |
| Jabsco | 29630-1201 |
| For Engines Type | C4.4 |
| Dimensions: | Ø A = 65,0 mm B = 50,0 mm Ø C = 18 mm Blades N° = 8 Insert: 12 Spline |
NOTE: This does not apply when major and minor kits are being used to service a JMP Marine brand pump #JPR-CT0440; this note only applies when internally servicing an OEM Genuine pump brand.
You can use the JMP parts Kits listed below to also service OEM / Genuine Brand pumps but MUST use CAT Mechanical Seal p/n: 4204328 in place of JMP Mechanical Seal MCSSET0008. MCSSET0008 is only for JPR-CT0440 JMP Marine Brand Pump.
Why was Mechanical Seal Changed?
To provide a longer life mechanical seal for longer lasting product and performance