All seals and washers should be renewed when replacing the filter so it is important that any old washer or sealing ring must first be removed. Failure to do this will result in an oil leak. Furthermore, the new ring or washer that is supplied with a cartridge filter should be smeared with engine oil so that it doesn't distort when you tighten the filter. The new cartridge should be tightened by hand only, NOT with the removal tool.

When all the oil has drained, the sump plug can be replaced and the engine filled with fresh oil, allowing some extra to fill the filter. Be careful not to overfill the sump, because the extra oil may damage the seals and cause the engine to pass the excess past the rings.

The last step is to start the engine, and check for leaks. Then drive a short distance and recheck, after the oil has warmed up.

Overfilling is extremely common amongst forecourt attendants, and it's worth your while to always supervise whenever oil is added to your engine. The best oil for your engine is one of the trade names and grades mentioned in the owner's manual, or else see the section on oils in this booklet.

The old oil should be taken to a collection point for the Rose Foundation (often the nearest garage), which will make sure that it cannot become an environmental risk.

Below: two of the many different kinds of filter- removing tools.

The black sealing ring on a filter must be replaced and has to be lubricated with oil before installation.