Sump plug size

[myglaren]

Changed oil + filter (Xantia 90Hdi) at the weekend.

I re-used the rubber/copper washer, but in addition wrapped just enough ptfe tape to go round the plug thread once, keeping it back awayfrom the start of the thread.

It beats me how oil filters tighten themselves between fitting and removing. I only tighten by hand, making sure there is no leak; despite this, when I remove it I invariably have to use a chain. And with attitude!

Pourquoi?

If I put a filter on, they always come off easily, never had one leak or unscrew itself though.
Had a struggle to get the one off the C5 first time but after that no bother.

[citronut]

maybe its to do with a smear of grease/oil on the filter seal on fitting,


regards malcolm

[myglaren]

I do always coat the seal with a little fresh oil. Maybe that is why they come off so easily.

Daughters SAAB was in for MOT and was having some new bits fitted and she had them do a service while they were on.
The guy was quite surprised at how easily the filter came off. I'll probably have a fight on my hands at the next service.

[John Plum]

You can re-use an all copper washer. Simply anneal it and it will be soft enough again to seal. It is a good idea to coat it with a little oil.
The washer gets hard on torquing up, that is why it should be annealed before re-use. If the washer is slightly deformed, then it can be filled flat before annealing.
This is old school practice and tried and tested on motorcycle engines without ever a fault. When you but a new washer for a sunup plug it is already annealed (or should be).

[Mandrake]

Good advice, but I think the original poster probably sorted out his problem 5 years ago.

When I had to fit a couple of copper washers to the "banjo" joint on the Automatic gearbox on my Xantia V6 in an emergency a few years ago (the normal washers are a Citroen only alloy part and would have taken me several days to obtain) I used Halfords copper washers of the right size and flame annealed them myself! They lasted without leaking for the year or so I kept the car after that...

[John Plum]

I hope so Mandrake.
Of course, I posted the update in order to make the post more complete for any new viewers.