Part 1. Preparation and safety
Objective
- Replace an oil filter to the manufacturer's specifications.
Personal safety
Whenever you perform a task in the workshop you must use personal protective clothing and equipment that is appropriate for the task and which conforms to your local safety regulations and policies. Among other items, this may include:
- Work clothing - such as coveralls and steel-capped footwear
- Eye protection - such as safety glasses and face masks
- Ear protection - such as earmuffs and earplugs
- Hand protection – such as rubber gloves and barrier cream
- Respiratory equipment – such as face masks and valved respirators
If you are not certain what is appropriate or required, ask your supervisor.
Safety check
- Make sure that you understand and observe all legislative and personal safety procedures when carrying out the following tasks. If you are unsure of what these are, ask your supervisor.
Points to note
- If the engine has been running, be careful not to burn your hand or arm on the exhaust manifold or any other hot part of the engine when reaching for the dipstick. The dipstick and the oil on it will also be hot.
- Although fresh oil is translucent, and oil that needs to be replaced looks black and dirty, it is often difficult to assess the condition of engine oil simply by its color. Oil loses its clean, fresh look very quickly and yet may still be serviceable. The best guide to changing oil is knowing the vehicle’s mileage and period of time since the last oil change.
- If the oil on the dipstick is not blackish in color but looks milky grey, this could indicate that there is some water (or coolant) being mixed into the oil. There may be a serious problem somewhere in the engine, such as leaking head gasket, and you should report this to your supervisor immediately.
Part 2: Step-by-step instruction
- Check new filter availability
Before removing an oil filter, first refer to the Service Manual for the vehicle and identify the type of filter required. Make sure that a suitable filter will be available as a replacement.
- Locate filter and correct tool
The filter will usually be located on the side of the engine block or at an angle underneath the engine. Some filters have a retaining nut which will require a box wrench to remove it, but most late model vehicles have filters, which are threaded cartridges. These are removed with an adjustable filter wrench.
- Remove filter and inspect
Remove the filter and clean the seating area on the engine so that its surface and the surface of the new filter can seal properly. Make sure that the seal from the removed filter is not still stuck to the engine.
- Obtain replacement filter
Confirm the correct part number and obtain the replacement filter from your spare parts supply. It is good practice to fit a new filter every time you drain the sump.
- Correctly fit replacement filter
Smear a little oil or grease on the surface of the new sealing ring. This will help to make a tight seal, but it will also prevent the gasket from binding and distorting while it is being tightened. Screw in the filter until the two surfaces are touching. To help judge the correct degree of the turn, make a mark on the outside of the filter with a pencil, or even a dab of oil, but remember to wipe the oil off again when you have finished. Do not over tighten the filter. Typically, three-quarters of a full turn is adequate torque for a seal that will not leak.
