First, the inner bore through the wire cage should allow easy entry of the cast bosses that extend inwards and locate each end, and a suitably sized screwdriver handle can be carefully worked through this central opening to reform any distorted wire structure, as well as better separate each fold for unimpeded flow, however the O.D. should still easily slide into and generally clear the housing's inner wall so that the full surface is available for the oil to flow easily over and around.

The filter ends should furnish a uniform surface for good sealing and if needed can be "persuaded" to adopt the desired form. A useful dodge here is to position a small pot magnet within the hollow bore held to a position of about one inch inboard of the right end, ie. the exit end where all outgoing oil will pass in front and within its active area. Locally and carefully shape the inner wire cage to prevent movement, especially towards the outlet boss to prevent it moving along to where it might block the all-important flow.

It is wise also to flush out the bypass valve located integral with the cap-end pressure plate, as well as the interior of the cap itself. When all has been serviced and the cap resealed you should refill the filter chamber through the long banjo type bolt (A22/1) opening, using a pressure spout oil can, to reduce harmful dry restart time.