Oil filter housing O Ring keeps blowing out

[Johny Boy]

Hi all.

I have an issue with the Oil filter housing O Ring, which keeps blowing out.

I have fully rebuilt the engine and everytime I start her up, after 2 or 3 seconds the O ring blows and deposits oil all over the floor.
I have bought a replacement cover and new o rings.
Today I have removed the oil pump pressure relief valve, the relief valve part did appear to be stiff in the bore, but having removed, cleaned it and refitted it seemed much better, but still with the same result.

I have also tried it once without the filter fitted, just to check, same result.

I am now at a total loss on how to proceed.
Any thoughts / advice would be most welcome.

Thanks

John

[Skoti]

Simple suggestion,

check if the oil filter housing is perhaps warped due to overtightening,
You could check this by sitting it on a glass shelf from your fridge (when the wife's not at home).

Good luck

[TrickyMicky]

If you still have the old cover, (undamaged!), try it with that and see if it still occurs.  Another point being, and I know this sounds daft, but, when you mount the cover, is it the right way up?

[Nurse Julie]

It sounds like the pressure relief valve is in the wrong way. We had this on a brand new OEM  NOS oil pump, never been fitted or used before on a CB550F. The pressure cracked the oil filter housing. Trigger investigated and found the relief valve was in the wrong way round.

[Johny Boy]

Thanks for all the answers, I checked the valve orientation this morning and it is the same as the picture from CMSNL i.e. Long end in first
I assume this right, as the spring locates nicely around the short end.

I have refitted the old housing and it blew it in half.....although it did have some cracks radiating out from the centre boss before I refitted it.
The crack propogated all the way ythrough the O ring groove.
I suspect it had previously been over torqued and the previous owner may have had the same problem.
Trouble is I can't check with them as it had been off road for a couple of decades before I bought it.

I have ordered a new housing and O Ring, but still think it is generating too much pressure.
But surely if the pressure relief valve is working then it should bypass pressure at the pump?

Does any one know how loose the valve should be in the pump casting, i.e. should it fall out if turned upside down or should it take a few bangs, mine does.

[Johny Boy]

If you still have the old cover, (undamaged!), try it with that and see if it still occurs.  Another point being, and I know this sounds daft, but, when you mount the cover, is it the right way up?

I think the Cover was right way up, so the thick lug engages with the slot on the crank case [ Guests cannot view attachments ]

[Nurse Julie]

If the relief valve is in correctly and the pump is assembled correctly, the only other logical reason is a blockage in an oil way/ gallery somewhere causing back pressure. Those oil filter covers really go with a very loud  bang when they go, it sounded like a gun going off.

[Johny Boy]

Thanks Julie

Yes it did go bang, unfortunatley I think you have just confirmed my worst fear...

I'm gonna have to take the engine out and strip it down again 
Still, should go quicker the second time and will give me something to do over the winter

[McCabe-Thiele (Ted)]

Before rushing to take the engine out I would firstly study the oil flow schematic diagram. I'm sure one has been posted before.

I can't see how you could completely block the oil galleries during assembly.

[Nurse Julie]

Realistically it can only be the pressure relief valve, blocked crank case breather or incorrect assembly of internal engine components.

[florence]

I would have thought crankcase pressure is at fault.  Gasket problem?  Breather?

[Bryanj]

Crankcase pressure wont blow the filter ring only oil pressure

[Bryanj]

To split the casing it has to be the pressure relief valve not working.
Even if there is a blockage anywhere after the pump the relief should open and dissipate the pressure

[Johny Boy]

Thanks Bryanj

That was my thought earlier, it should bypass any over-pressure at the pump.

I still can't figure out why it's not working.
Valve shuttle sticking? It took some banging to get it out the first time, not so much after I took it out and cleaned it.
Old / wrong Spring fitted? It seems to fit and an old spring should get softer as it ages meaning lower relief pressure.

However I can't work out a way to test it outside of the engine.

I will have to take the oil pump off again tomorrow and see if I can figure it out

[Bryanj]

One possibility, is the outlet from pressure relief valve blocked? I ha rebuilt lots of pumps but never checked where the oil goes if relief opens!