please don't use WD40, which is not a lubricant and can gum.
It's good to use as a handy penetrator, as specified in my post, the area was then to be cleaned out, with light grease applied to the plunger and spring to prevent this happening again.
I do hope the OP removes all series 80 components and sticks with the original proven design![]()
If my FP is broken, can I use a Series 70 FP?



























