Mitsubishi GS16-GS25 filter replacement
The three filters of your Mitsubishi GS16-GS25 are the cheapest life insurance for your engine. On this page you'll learn which oil, fuel, and air filter fit the GS16, GS18, GS20, GS21, GS23 and GS25, when to replace them, and which original part numbers guarantee you're getting it right.
Suitable for the entire series: Mitsubishi GS16, GS18, GS20, GS21, GS21S, GS23, GS25 and GS25S with S3L/S3L2 engine.
Mitsubishi GS16-GS25 filters and part numbers
Because the entire series runs on the same S3L/S3L2 engine, the filters are identical across all models. These are the original part numbers from the manual:
| Filter | Original number (OEM) | Replacement interval |
|---|---|---|
| Engine oil filter (cartridge) | 31A40-02100 | 1st time 50 h, then every 100 h |
| Fuel filter (element) | 31A62-00317 (complete: 31A62-00300) | Clean 50 h, replace 200 h |
| Air filter element | 3546-0501-800 | Check/clean 100 h, replace if damaged |
| Hydraulic oil filter (cartridge) | 1038-2585-000 | 1st time 100 h, then every 300 h |
The O-rings of the fuel filter housing (31A62-00318 large, 31A62-00319 small) should be replaced with every element change — this prevents air leaks in the fuel system.
Replacing the Mitsubishi GS16-GS25 engine oil filter
The engine oil filter is a spin-on cartridge. Loosen it (use a filter wrench if it's stuck), wipe the sealing surfaces clean, and lightly coat the gasket of the new filter with oil. Tighten it by hand until the gasket touches the sealing surface, then turn it about another 2/3 turn. Since the new filter fills with oil, check the oil level after starting the engine and top it up to the upper mark.
Replacing the Mitsubishi GS16-GS25 fuel filter
Replace the fuel filter element every 200 hours, and clean it in between every 50 hours. After replacing it, bleed the fuel system — air in the line is the most common cause of an engine that won't start or runs unevenly after a filter change. Immediately check for fuel leaks at the connections.
Replacing the Mitsubishi GS16-GS25 air filter
Check and clean the air filter every 100 hours, and more often in dusty conditions. A clogged air filter immediately costs power and increases fuel consumption; it's also a classic cause of black exhaust smoke. Gently tap out the element or blow it through from the inside; if it's damaged or deformed, replace it.
Replacing the Mitsubishi GS16-GS25 hydraulic filter
The hydraulic oil filter is a cartridge located under the left footplate. Replace it for the first time after 100 hours, then every 300 hours. Coat the gasket here as well, tighten by hand plus 2/3 turn, and make sure the filter is truly secure: a loose hydraulic filter draws in air and causes a slow or jerky lift.
Product tip. The most cost-effective way to replace all three engine filters at once is with the Filter set Mitsubishi GS series (SKU-100164) — assembled to the original GS part numbers and suitable for both the GS16-GS25 and the GS160-GS250. Prefer them separately? Then get the oil filter (SKU-018), the fuel filter (SKU-150009) and the air filter (SKU-20021) separately — the latter explicitly lists the GS16-GS25.
