How to Change a Cartridge Oil Filter

by Kyle McBride

Canister or cartridge type oil filters are common on certain vintage automobiles such as old Mercedes Benz, as well as in industrial and marine diesel applications. They are also useful in any remote-mount filtering setup. Unlike spin-on filters, which are self-contained units, canister filters have several separate parts. Bypass valves and drain plugs are mounted in the canister that houses the filter element. The filter base bolts to the canister and mounts the assembly to the engine or remote mount support as well as housing the oil passages into and out of the filter.

Changing the Element

Loosen the drain (wingnut or plug) located on the bottom of the canister. Collect the drippings with the catch pan. Tighten the drain back and wipe off the canister, drain and mounting bracket. Make sure there is no dirt or debris that may fall from the bracket into the canister during reassembly.

Loosen the bolt on top with the wrench that mounts the canister. Grasp the canister with the rag and remove the bolt and washer from the mount bracket. Lower the canister away from the mount and keep it upright to contain any residual oil.

Pull the element out of the canister and discard the element. Check the canister and the machined surface of the bracket for O-rings or debris and remove. Wipe the mating surfaces of the canister and the bracket with a clean rag. Invert the canister in the catch pan and allow it to drain fully. Inspect the canister for silt and debris. Wash the canister in a parts washer or with some clean diesel to remove any sludge. Drain well after washing.

Select the proper O-ring for your canister (there will be several to choose from in the kit) and lubricate it with a light coat of clean engine oil. Place the O-ring into the recess in the top of the canister. Insert the new element into the canister and push it onto the stud in the bottom of the canister.

Install a new crush-washer from the kit onto the top bolt. Hold the loaded canister in position under the bracket and hand-start the top bolt. Tighten the bolt hand tight then torque it lightly with the wrench. Re-check the drain and make sure it is tight. Wipe the whole assembly with a clean rag to remove any residual oil on the outside. This will aid in checking for leaks.

Start the engine and observe the oil pressure gauge. Once pressure is established, observe the canister and watch for leaks. Most leaks will be readily apparent, but some may show up only once the engine is at operating temp. Check it again once the engine warms up.


  • close If the engine is hot when the oil is changed, the oil can be hot enough to scald bare skin. Wait until the canister is at least cool enough to tolerate before beginning the process. Certain normally aspirated engines and most turbo engines require the canister to be primed with fresh oil prior to assembly. Check with your manufacturer before passing this point or else engine damage could occur. Do not run the engine long without any registered oil pressure. This may indicate a leak or the need to prime the filter.

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