Most PC400 enquiries we get start as a PC300 order with one word changed. The buyer has been running 30-tonne machines, buys a used 40-tonne unit, and assumes the filter list carries across because the machines look like the same family in a photograph. It does not. The PC300-8 runs the SAA6D114E-3; the PC400-8 runs the SAA6D125E-5, and almost every element in the set changes with it.
The machine the numbers belong to
Komatsu's PC400-8R brochure gives the figures below. Worth reading before the filter list, because the engine code is what the whole set hangs on.
| Specification | PC400-8R | PC400LC-8R |
|---|---|---|
| Engine | Komatsu SAA6D125E-5 | Komatsu SAA6D125E-5 |
| Gross power | 270 kW / 362 HP at 1,900 rpm | 270 kW / 362 HP at 1,900 rpm |
| Net power | 257 kW / 345 HP at 1,900 rpm | 257 kW / 345 HP at 1,900 rpm |
| Operating weight | 41,740 – 42,590 kg | 42,290 – 43,200 kg |
| Bucket capacity | 1.30 – 2.80 m³ | 1.30 – 2.80 m³ |
| Standard equipment relevant to filters | Corrosion resistor; dry type air cleaner, double element | Corrosion resistor; dry type air cleaner, double element |
Source: Komatsu PC400-8R / PC400LC-8R brochure CEN00273-05 (komatsu.com), read 4 November 2026. Emissions: U.S. EPA Tier 2 / EU Stage 2 equivalent, with the Heavy Duty High Pressure Common Rail (HPCR) fuel system.
The six numbers, at the sizes Komatsu publishes
Komatsu's parts site gives a specification page for each number — style, height, and where applicable length, width, media and gasket count. It does not give a machine list. So the table below is Komatsu's own data, and the machine fitment for five of the six comes from supplier catalogues, which is a weaker source and is labelled as such.
| Circuit | Number | Komatsu's published name | Style | Published size | Media |
|---|---|---|---|---|---|
| Engine air | 600-185-6100 | Air Filter Kit | Element Kit | H 524 × 313 × 313 mm | High Efficiency |
| Hydraulic | 208-60-71123 | Eco-White Hydraulic Filter | Element | H 178 × 200 × 178 mm | Glass Fiber |
| Engine oil | 600-211-1340 | Engine Oil Filter | Element | H 330 mm | Dual |
| Main fuel | 600-319-3841 | Main Fuel Filter | Cartridge-Element | H 278 mm | Dual |
| Pre-fuel | 600-319-4540 | Pre-Fuel Filter | Cartridge-Element | H 343 mm | not published |
| Corrosion resistor | 600-411-1151 | Corrosion Resister Filter | Cartridge-Element | H 133 mm | not published |
Sizes, styles and media: Komatsu part pages for each number (komatsu.com), read 4 November 2026. Where Komatsu prints no media grade for a number, the cell says so rather than borrowing a figure from a filter maker's cross-reference. All six carry a protective cover and one gasket except the air kit, which is a bare element kit without a cover.
The main fuel filter exists under two live numbers
This is the part that catches people. Both of these pages are live on Komatsu's site today, both are called Main Fuel Filter, both are Cartridge-Element with a protective cover and one gasket:
| Number | Height | Media | What the catalogues say |
|---|---|---|---|
| 600-319-3550 | 285 mm | not published | Older number, listed against PC400-7 and PC450-7 |
| 600-319-3841 | 278 mm | Dual | Newer number, listed against PC400-7, PC400-8, PC450LC-8 and PC490LC-10 |
Seven millimetres. In a housing that holds the cartridge under a fixed-depth cover, seven millimetres is not a tolerance — it is a different part. Two consequences follow. First, a supplier who crosses the machine to 3550 when the serial number calls 3841 will send a filter that does not seat, and the machine goes down for a week over a part worth less than the freight. Second, because both numbers are live, a search result that shows one is not evidence about the other.
The honest procedure is the same one we ask customers to follow: read the element that comes out. If you cannot, give us the serial prefix and we will quote against the parts book rather than against a catalogue cross. That is also why our 600-319-3841 page shows the height in the specification table and asks for the old element's measurement before the order is confirmed.
Hours, not kilometres: the interval table
Komatsu prints the maintenance schedule in the brochure and repeats it on the machine monitor, which counts down each item. The numbers are fixed, so the annual parts requirement is simple arithmetic:
| Item | Komatsu interval | Per 2,000 hours |
|---|---|---|
| Engine oil and engine oil filter (600-211-1340) | 500 h | 4 services |
| Fuel pre-filter (600-319-4540) | 500 h | 4 elements |
| Hydraulic tank breather | 500 h | 4 elements |
| Main fuel filter (600-319-3841) | 1,000 h | 2 elements |
| Hydraulic oil filter (208-60-71123) | 1,000 h | 2 elements |
| Hydraulic oil | 5,000 h | 0.4 changes |
Source: Komatsu PC400-8R brochure maintenance table and "long-life oil, filter" page (engine oil and filter every 500 hours, hydraulic oil every 5,000 hours, hydraulic oil filter every 1,000 hours). Annual figures are our arithmetic on a two-shift machine, not a Komatsu statement.
Two practical notes. The 500-hour items are the ones that actually get skipped in the field, because four pre-fuel elements a year sounds like a lot until you price a high-pressure fuel pump. And the 1,000-hour fuel interval is a dust-free-fuel interval: on a site where drums are decanted through a funnel in the open, the element is done long before the monitor says so. Shortening it is cheap insurance; stretching it is not.
Air kit and hydraulic element: the two numbers people mis-order
600-185-6100 is published as an Air Filter Kit in Element Kit style, 524 mm high at 313 mm square, High Efficiency media, white, no protective cover. Komatsu's air cleaner element publication lists it against the PC400-8 alongside the D155AX-6, WA800-7 and HD785-7, and gives the element case outer diameter for that group as 381.0 mm. That 381 mm is the useful number in a warehouse: if the housing bore does not measure about 381 mm, the element in your hand is for another machine, however plausible the label looks. The brochure specifies a dry type air cleaner with two elements, so the inner element is a separate item and belongs in the same order.
208-60-71123 is the Eco-White hydraulic filter, 178 mm high at 200 × 178 mm, glass fibre media in a metal can with no protective cover. Komatsu describes the Eco-White family as return-line filters with premium glass fibre media. Do not confuse it with 207-60-71181, the 20-to-30-tonne class element, or with the Eco-White 207-60-71182 used on that same class at 200 × 150 × 150 mm — a 50 mm difference in two directions, and no amount of persuasion at the counter makes it fit.
What to put on the order sheet
- Serial prefix, not just "PC400-8" — the fuel filter change is serial-dependent.
- Heights of the elements coming out: 285 or 278 mm settles the fuel question in ten seconds.
- Air cleaner housing bore: 381 mm for this class; anything else means the number is wrong.
- Inner air element: the double-element cleaner means two elements per air service.
- Interval policy: state whether the machine is on Komatsu's 1,000-hour fuel interval or a shortened site interval, so the quote covers a year rather than a service.
We stock the PC400-8 set — 600-185-6100 air kit, 208-60-71123 hydraulic and 600-319-3841 main fuel — and ship FOB Shanghai or CIF to your port. The same method for the 30-tonne class is in the PC300-8 / PC350-8 filter set guide, and the filters catalogue lists what we hold across the Komatsu, Cat and Kobelco ranges.
Frequently asked questions
What filters does a Komatsu PC400-8 take?
Six service filters: air element kit 600-185-6100, hydraulic element 208-60-71123, engine oil filter 600-211-1340, main fuel filter 600-319-3841, pre-fuel filter 600-319-4540 and corrosion resistor 600-411-1151. Komatsu publishes a specification for each of those numbers; the machine lists on parts websites are supplier crosses, so the parts book for your serial number still decides.
Is 600-319-3550 the same filter as 600-319-3841?
No. Both are Komatsu Main Fuel Filters in Cartridge-Element style with a protective cover and one gasket, but 600-319-3550 is published at 285 mm high and 600-319-3841 at 278 mm, and only 600-319-3841 lists its media as Dual. Supplier catalogues print them as the old and new number for the PC400-7 and PC450-7 and list 600-319-3841 for the PC400-8 and PC450LC-8. Seven millimetres is enough that the two will not interchange in a housing with a fixed cover depth, so measure the element you take out instead of crossing by name.
How often do the filters need changing on a PC400-8?
Komatsu's own maintenance table in the PC400-8R brochure sets engine oil and engine oil filter at every 500 hours, fuel pre-filter at 500 hours, main fuel filter at 1,000 hours, hydraulic oil filter at 1,000 hours, hydraulic oil at 5,000 hours and the hydraulic tank breather at 500 hours. On a machine running 2,000 hours a year that is four oil and oil filter services, four pre-fuel elements, two main fuel elements and two hydraulic elements a year.
Will PC300-8 filters fit a PC400-8?
Not the set. The PC300-8 runs the SAA6D114E-3 engine and the PC400-8 runs the SAA6D125E-5, and the numbers that matter differ: air element kit 600-185-5110 at 405 × 282 × 282 mm against 600-185-6100 at 524 × 313 × 313 mm, hydraulic 207-60-71181 against the Eco-White 208-60-71123 at 178 × 200 × 178 mm, engine oil 6742-01-4540 at 302 mm against 600-211-1340 at 330 mm. A 40-tonne machine needs its own set.