Komatsu 600-319-3841 Main Fuel Filter

Two Live Numbers, Seven Millimetres Apart

Most parts numbers resolve one way: an old number supersedes to a new one and the old one dies. This pair did not. Both 600-319-3550 and 600-319-3841 are live Komatsu articles today, both called Main Fuel Filter, both Cartridge-Element, both with a protective cover and one gasket. The only published difference is height — 285 mm against 278 mm — and the media field, which Komatsu fills in for 3841 as Dual and leaves blank for 3550.

Seven millimetres in a housing that seats the cartridge under a fixed-depth cover is the difference between a filter that seals and one that does not. That is not a tolerance question and it is not something a cross-reference table can resolve, because the table is built from the machine model, and the change happened inside the model run. What resolves it is the parts book for the serial number, or the element that comes out of the housing with a rule held against it.

Why the Fuel Side Is Where the Money Is

The SAA6D125E-5 in the PC400-8 runs a Heavy Duty High Pressure Common Rail fuel system. Everything upstream of the injectors exists to keep that system clean: the pre-filter at 343 mm catches water and coarse contamination on a 500-hour interval, and this main element finishes the job at 1,000 hours. Skimping here does not show up as a filter problem — it shows up as a pump or an injector, usually on a machine that has just been moved to a new site with a new fuel supplier.

Two habits pay for themselves. Change the pre-filter on the 500-hour mark even when the main element is not due, because the pre-filter is the one doing the water separation. And keep one spare main element on site: a machine down for a week waiting on a filter that costs less than the freight is the most common avoidable downtime we hear about from fleets in West Africa.

Confirming the Number Before the Order

Three checks, in this order. Read the height of the old element: 278 mm means this number, 285 mm means 600-319-3550. Look at the cover: both are cartridge elements under a protective cover, so the housing looks identical either way — which is exactly why the height matters. And take the serial prefix off the plate, because if the machine has had a short block or a fuel system retrofit, the model year alone will mislead you.

Ordering the Full Fuel Service

This element is normally ordered with the 600-319-4540 pre-fuel filter, and often with the 600-185-6100 air kit and 208-60-71123 hydraulic element on the same 1,000-hour service. The PC400-8 filter number guide covers all six numbers and the interval table; for the smaller class, the PC300-8 / PC350-8 guide runs the same method on the SAA6D114E-3 machines.

FAQ

Q: What is the height of the Komatsu 600-319-3841 fuel filter?
A: Komatsu publishes 600-319-3841 as a Main Fuel Filter in Cartridge-Element style, 278 mm high, dual media, black, with a protective cover and one gasket. The number it is most often confused with, 600-319-3550, is published at 285 mm in the same style with the same cover and gasket count — seven millimetres taller, and a different article.

Q: Is 600-319-3841 the new number for 600-319-3550?
A: Supplier catalogues treat it that way: they print 600-319-3550 as the older main fuel filter and 600-319-3841 as the newer one for the PC400-7 and PC450-7, and list 600-319-3841 against the PC400-8 and PC450LC-8. Komatsu itself publishes both numbers as live articles with different heights and does not print which machine takes which. Because the running change is serial-dependent, the parts book for your serial decides — not the catalogue.

Q: Can I use 600-319-3550 if I cannot get 600-319-3841?
A: Only if your machine was built for it. The two elements are 285 mm and 278 mm high in a housing that holds the cartridge under a fixed-depth cover, so they are not interchangeable on the machine. Fitting the taller element into a housing sized for the shorter one, or the reverse, risks a cover that will not seat and an air path into the fuel — on a common rail system that is a pump repair, not a filter change.

Q: How often is the main fuel filter changed on a PC400-8?
A: Komatsu's PC400-8R maintenance table sets the main fuel filter at every 1,000 hours, with the fuel pre-filter at 500 hours. The pre-filter is the one that catches water and coarse dirt first, which is why it is on the shorter interval. On sites where fuel is decanted from drums in the open, both intervals are worth shortening; the element is cheap compared with the high-pressure fuel system it protects.