Oil pump, what this bit?

[skelteanema]

Hi all,
I was changing the oil and filter on the car today, when I unscrewed the filter I found the bit in the photo sitting on top of the filter.

It is a spring loaded valve, about 15mm across at a rough guess. It is lucky I saw it as it could have easily fallen in the waste oil container and I wouldn't have noticed it was missing. Questions:
What is this piece for?
Which way up does it go in the pump? (I will probably find it will only go one way, springs out as a guess)?
Can I just refit it or do I need a new pump? If I can refit it, how do I stop it from falling out again?

I replaced the old (high pressure) pump with this one only a couple of years ago so will be a bit peeved if I have to replace it again. The high pressure pump doesn't have this valve, the place it goes has a metal blanking plug instead.

Thanks for your help

[rgh0]

Its a relief valve to bypass the filter if it blocks so then engine is not starved of oil. If it falls out the filter get continuously bypassed. The hp/hv pumps just have a blanking plate I guess because people figure they are used on competition cars that get lots of oil changes and unlikely to ever block the filter.

cheers
Rohan

[oldelanman]

Here's how it fits in the old paper element filter type pump.......

[skelteanema]

Thanks Rohan, Roger,
thats what I thought it probably was. The photo shows ow it goes in place.

It looks like it is a press fit; can I just push it back in? Is there a way of securing it in place? I suspect the filter housing would stop it falling out again, but would prefer it to stay in place on its own.

Thanks,

[ardee_selby]

It looks like it is a press fit; can I just push it back in? Is there a way of securing it in place? I suspect the filter housing would stop it falling out again, but would prefer it to stay in place on its own.

Thanks,

I've taken the liberty of enlarging a section of Rogers pic. It shows the "crimps" that (should) retain it.

HIH - Richard

[oldelanman]

Hi Skittle,
The one I've shown above is staked in two places which you can just about see if you look closely. Since yours already fell out I would be inclined to do the same to make sure it stays put.

Edit.....Just beat me to it Richard.

[ardee_selby]

Edit.....Just beat me to it Richard.

Maybe, but you used the proper term..."stake" not crimp. D'oh!

Richard

[skelteanema]

Thanks guys,

I will have to go under the car again and have another look. I didn't see any stakes when I had a look, Thats whay I thought it was a push fit. Then again I didn't look very hard as it was getting dark, and I was still cursing after bashing my knuckles when trying the get the oil filter loose.

I am surprised that it would come loose as it was a new pump only a couple of years ago and hasn't had much mileage on it.

[rgh0]

I have had the metal blanking plate that fits in the same location on a hp / hv pump fall out in the same way. I now check every pump to ensure the vallve or blanking plate is properly staked before fitting the pump. The quality of manufacture of the replacement pumps these days is not the greatest.

cheers
Rohan

[skelteanema]

Hi,

well I got under the car last night, and had a look around. There were two grooves either side of the aperature where the valve goes, but no obvious stakes. One of the grooves slopes down towards the valve, whereas the other was flatish across the top. I looked at my old hp pump and it was the same, so it doesn't look like anything has broken or moved. I think the valve may have dislodged when I removed the filter as I remember it caught when trying to unscrew it, and I had to back it off then unscrew its again to get it out.

I refitted the valve, it required a few taps to seat it correctly. I then ground an old valve down to a flat blade like a screw driver (i.e. not too sharp) about the width of the grooves, and gave a few light taps in these grooves on either side using a very small tack hammer. On the flat groove, this put a dent in the metal and a slight bulge towards the valve. On the sloping one, I couldn't see much change. I didn't want to hit it too hard. The valve seems tight now as I couldn't move it by hand.

Do you think this will be OK or should I remove and replace the pump? If this valve drops out, do you get a drop in oil pressure as the oil by-passes the filter?

Thanks,

[ardee_selby]

Do you think this will be OK or should I remove and replace the pump? If this valve drops out, do you get a drop in oil pressure as the oil by-passes the filter? Thanks,

It appears you have achieved what wasn't during manufacture so, yes, should now be OK.

No need to replace the pump (it's only had two years use) but if you were prepared to remove it...for peace of mind you could re-stake on a bench where you have more control & see the results close up?

As Rohan has said "It's a relief valve to bypass the filter if it blocks so then engine is not starved of oil. If it falls out the filter get continuously bypassed"

So unless (heaven forefend ) you were running with a blocked filter which would have opened the valve anyway, and if it then became dislodged, any small pressure drop would have already happened...wouldn't it?

Good Luck - Richard

[skelteanema]

Thanks Richard and others. I went back under the car again last night and I put additional stakes in a different position to the original just to reassure myself. The setup is a bit different to that in the picture oldelanman supplied as it doesn't have the raised edge around the valve recess, rather it is flush with the surrounding metal. I put a couple of dents perpendicular to the valve so I am reasonably confident that it won't come out now. I have reattached filter (first filled with oil) and filled up the engine with nice clean oil. Now to lube the trunnions and steering.

It is a bit of a concern that you have to check critical items such as oil pumps to make sure the bits are correctly fitted and fixed when they are new, especially when obtained from a reputable source. Now I know to check in the future (and I will be checking this valve at every oil change from now just to make sure I have chucked it out with the used oil). Makes you start wondering how many of these may have fallen out unnoticed, as it is not something you check when changing the oil and filter.