Oil filter cap

[chakadog]

Well 300 miles over my oil-change interval so thought I'd quickly take care of that over the weekend (extractor, new filter, take the old oil to AutoZone, etc).

Well, the old filter wouldn't easily come out of the cap, so in the application of the muscle to get it it out of there, off came the internal spring-loaded valve or whatever that fits in the top of the oil filter itself. You'll notice a little piece of plastic broke off—can't really explain that.

In researching this I found some references as I recall on the Disco3.uk site to a service bulletin where service techs were throwing this piece in the trash along with the used filter!

I couldn't get the piece to snap back in so just positioned it correctly with the filter and screwed the cap back on for a temporary fix until a new cap arrives.

Questions

Can someone explain the function of that spring-piece at the top of the filter?

Anyone else have this issue?

ALSO somehow I ended up with Delco filters and they are made with every-so-smaller openings on the top. Tolerances are so tight the o-rings were not compressing enough to get the cap on properly. Re-ordered OEM from Atl. Br. we'll see if those are better.

 

[ktm525]

It's the bypass valve in case the filter gets clogged the pressure will depress the spring and your engine will still get oil flow. Dirty oi is better than no oil.

Wix, Mahle or Mann for me. Never used a Delco so dunno.

 

[mm3846]

My truck doesn’t have that, and I noticed the same thing with Delhi filters

 

[Rover Range]

The bypass valve can be snapped back into place.
Align the tabs properly.
Then use a socket and an extension to push back in place.

 

[ktm525]

My truck doesn’t have that, and I noticed the same thing with Delhi filters

I would expect nothing less from a Delhi filter.