About this part
326-4635 is supplied as a remanufactured replacement fuel injection pump. Cross-reference numbers: 326-4635, 3264635. Application recorded for this part: Fits Caterpillar — CAT 320D C6.4 C6.6.
This pump has two jobs that are easy to conflate: raising fuel to injection pressure, and metering the correct quantity at the correct moment. Wear affects both. The result is usually a combination of harder starting, drifting timing and visible smoke rather than one clean fault.
Look for extended cranking, especially hot, poor throttle response, smoke across the rev range, fluctuating idle speed, and a gradual rise in consumption that cannot be explained by duty cycle.
Confirm you actually need a pump. Verify supply pressure at the inlet, check for air ingress and restrictions, and have delivery and timing tested on the bench — many 'worn pumps' turn out to be supply faults.
Key points: align to the timing marks rather than forcing the drive, prime before cranking, renew seals, confirm adequate supply pressure from the lift pump, and bleed the system fully. Skipping any of these is where most comebacks originate.
Rebuilt rather than refurbished: full teardown and measurement, worn components replaced instead of cleaned and reused, sealing surfaces restored to specification, then bench calibration and testing. The record is what separates this from a used part — we can provide the test sheet for your order. Covered by a 12-month warranty.
Specifications
| Part number | 326-4635 |
| Condition | Remanufactured (not a genuine OEM new part) |
| Cross-reference | 326-4635, 3264635 |
| Application | Fits Caterpillar — CAT 320D C6.4 C6.6 |
| Process | Disassembled, cleaned, measured, wear parts replaced, machined to specification |
| Bench test | Delivery, return flow, opening pressure and leakage recorded before dispatch |
| Warranty | 12 months |
Fitment note. Several part numbers in this family look similar. Confirm the number on your
existing unit, the engine model and the machine or vehicle application before ordering. Send us a nameplate photo
and we will verify the match before dispatch.
All manufacturer names, symbols and part numbers are used for identification and cross-reference purposes only. We are not an authorised distributor and are not affiliated with the original equipment manufacturer. Products offered are remanufactured or new aftermarket replacement parts unless stated otherwise.
