Dismantling oil filter bolt

[badger_eng]

The spring sits on the roll pin, it pushes against a small metal cup, with the spring sitting inside the cup. The cup blocks holes in the filter bolt, however if the filter collapses or blocks enough to stop oil flow the pressure of the oil pushes the cup down against the spring pressure and that means the holes it was blocking are now exposed. The oil uses these holes to bypass the filter so stopping the engine from seizing. Get a small sharply bent piece of metal and push down on the cup, it should move, if it doesn’t you have a problem and you’ll need to dismantle the bolt to free it off.

Thanks Oddjob. A better explanation than my simplistic version :-)

[Athame57]

The spring sits on the roll pin, it pushes against a small metal cup, with the spring sitting inside the cup. The cup blocks holes in the filter bolt, however if the filter collapses or blocks enough to stop oil flow the pressure of the oil pushes the cup down against the spring pressure and that means the holes it was blocking are now exposed. The oil uses these holes to bypass the filter so stopping the engine from seizing. Get a small sharply bent piece of metal and push down on the cup, it should move, if it doesn’t you have a problem and you’ll need to dismantle the bolt to free it off.

Thanks for this Odjob, I'll be doing this at my next oil change that is coming up soon. 

[Oddjob]

I would suggest checking the oil pressure relief valve on the oil pump at the same time George. Not as easy to check though I’m afraid.

[Athame57]

I would suggest checking the oil pressure relief valve on the oil pump at the same time George. Not as easy to check though I’m afraid.

I'm soon to have the seals on my oil pump changed ( got them from Julie) I'll get it done then. Thanx mate!