Hitchcocks Forum

I recently changed the oil and filter on my 2015 C5, a job I've done several times since buying it new. After a brief ride it became apparent that there is an oil leak from the filter plate. I therefore took it off again to see if the O ring had become displaced. It hadn't and as far as I can tell the surfaces of the plate itself and the crankcase are fine. I therefore rotated the O ring and put it all back together. Today I went for a ride and it's leaking again. It seems to me that the groove in the filter plate is too wide for the supplied O ring. I should add that all three threads are fine and that I torqued the nuts up to the specified figure both times. My question is whether or not it is permissible to smear the plate with a light coating of silicone. (Having once blocked the rocker supply on an old Norton by using Hylomar I won't use that as it tends to have bits break away). Any thoughts? It just seems weird that this hasn't happened before and I've done nothing differently.

With the 3 screw cover plate the oil can end up in the lower threaded hole and tends to make itself known for several hundred miles after and oil change if not cleaned out thoroughly.

Thanks Ric; that makes sense because it definitely appears to be the area around the lowest hole of the three that the oil is leaking. I'll fit a new O ring and clean out the hole.