Filter cover oil leak

[Jack Leis]

More to be revealed Jim.

[Ducati Scotty]

As I mentioned above, beefier is not better.
To work right, the O-ring must be the right size.

Too large of an inside diameter, too thick of a cross-section or both will doom it to failure.

+1.

[mattsz]

When I took delivery of my bike, I asked the dealer to bring along two oil filters and requisite o-rings.  He brought the filters, and a pair of rings that looked like they should fit the cap.  When we changed the oil the first time, it was apparent that this ring, while seemingly the correct overall diameter, was too "thick" in cross section to fit easily into the recess on the cap.  We reused the ring that was there, and I did the same again for the second oil change.  I have since gotten a slew of o-rings in the oil change kit from NFG - including what looks like rings to match the size installed.  You'd hope that the dealers would get it right...

[gremlin]

.............You'd hope that the dealers would get it right........

Hope in one hand & .........

[Jack Leis]

Hope in one hand & .........

    Plus One Gremlin !

[LarsBloodbeard]

This forum is a hoot!  I've had an intermittent leak from that oil filter cover since I got the bike.  Last night I changed the oil & filter.  This time they gave me a new o-ring with it... well, I'll be darned if it isn't the correct size now.  I thought that old one looked a bit small in that groove!

[Jack Leis]

Thats what Im talking about. In my case, Nfield gear on the left, Hitchcock's on the right.

[Arizoni]

Actually, the packing on the left looks to me to be the right size if it is a stretch fit on the inside diameter and it is protruding about .010 above the adjacent metal diameter of the cap.  The side to side clearance in the slot must have clearance.

The one on the right could be the right size but before installing it I would check to see it slips loosely down into the packing groove. It should clear the walls of the groove by about ten thousandths of an inch (3 pieces of printer paper).
If the Hitchcock one is a tight fit (side to side) it is the wrong one.
If the Hitchcock one is a loose fit (side to side) it probably is okay to use as long as it isn't sticking out above the adjacent metal cover diameter over .020".

[maxrotor Afro Samurai]

Guys.. Guys.. its a brit bike.. if it doesnt leak oil.. how can you tell if it works?.. ha.. ha... dont get mad at me...

Just did my oil change.. with parts from nfield gear... now I am worried... will have to check when I get back...

I bought a slew of orings.. from mcmastercarr.com  .. all diff sizes.. anybody got any measurements on the oring size that wont leak?.. surely a metric size?.. or standard size?... looks like I need to make a call to parker oring.. and get something speacial out fo stock.. one of those "x" cross section types...

ok... somebody just answered part of my questions.. thanks Arizoni

[LarsBloodbeard]

Thats what Im talking about. In my case, Nfield gear on the left, Hitchcock's on the right.

The one on the left was in the bike when I got it, the one on the right was from Doug Douglass.  I've bought 2 filters from them, the first had no o-ring, the second had 2 o-rings.

The cap slipped on very easily (loosely) with the old one.

[mattsz]

Lars-

I can't tell much from your photo, but those rings look kind of like what I had.  Only, the slighter one, like the one on the left, was what was installed and fit fine, and didn't leak.  The beefier one, like on the right, was supplied from the dealer, along with the filters, and it didn't fit - it was just a hair too big...

[LarsBloodbeard]

Without a micrometer, it's hard to compare yours to mine.  But like I said, the cap was a loose fit.  Also there was plenty of room in that o-ring channel.  The larger one looks more correct to me.  Time will tell if the leak is gone...

[Jack Leis]

 The first time I ever changed my filter I bought one that came with a cap o-ring from Art at Douglas and it never leaked. He spoiled me ! I bought the "big kit" from Nfield gear and that's when the problems started. As you stated Lars, time will tell.

[singhg5]

I had measured the size of these O-rings with a caliper and came up with numbers in the picture below. I would say these are the best estimates - may not be absolute numbers.

Smallest one =  9mm id  and 13mm od
Middle one   =  35mm id and 42mm od
Large one     =  42mm id  and 48mm od

I must say that it is not so easy to accurately measure because O-ring changes shape with slightest pressure and readings change. Even while measuring thickness, it can compress easily and give different values.

[singhg5]

These are pictures of one of the O-rings in caliper.