Hi All,   I have recently developed an annoying oil leak which appears to come from the spin on filter. I fitted a new K&N filter with a wipe of oil around the seal and then tightened by hand plus three quarters of a turn (as per instructions on the filter). But I still get a leak.. It always seems to be in the same place at the rear of the filter ie above the clutch slave cylinder. My spin on adaptor is 14 years old and one of the early types without the spring loaded centre section of