Step 1. Place a drip tray under the filter, and undo the securing bolt. This will be at the base of the bowl, or on top of the filter housing.

2. Remove the bowl and tip the contents into a suitable container. Note the arrangement of any springs and washers around the centre bolt.

3. There will be a sealing ring in a groove in the filter housing. Use a skewer or some other pointed instrument to spear it and ease it out.

4. Clean dirt from the groove with a corner of cloth and insert the new rubber ring supplied with the filter element. Take care not to twist the ring—if necessary using a mirror to check it.

5. After washing the filter bowl in paraffin to remove any sludge, insert the new element.

6. Position the bowl against the sealing ring and hold it firmly in place while the fixing bolt is hand-tightened. Finally tighten the bolt with a spanner.

7. With the engine sump filled with oil, check for leaks at the filter while the engine is running. Leaks are usually caused by a loose fixing bolt, or an improperly seated or twisted sealing ring.