r90 oil filter

[jagarra]

Doing an oil change for the Summer, noticed my original BMW oil filters are old stock superceeded by 3 later numbers. this number is 11421253919. I was running some after market units which had a rubber grommet/lip on both end where it slid onto a center shaft/bolt.
So are filters OKAY??? these have no such rubber grommet.

After checking parts micro fiche i found that I needed to order some rubber o rings for each end. Something strange also turned up, when I opened every box with the same OEM part number, 2 filters had rubber ends and 2 did not.

[Zombie Master]

If they have the rubber ends I would imagine you would not add O rings. have a look into the filter chamber to see if there is a remaining O ring or stuck rubber end. Check the size of the filter!!!

[jagarra]

I did find an old O ring buried at the end of the filter cavity, it was hard as a rock. The replacement O-rings were surprisingly expensive $5.00 plus change for each, but it will allow me to use the 2 filters without the rubber bit.
I can see why they went to a new style hinged filter, in order to remove and install the straight one piece unit I had to remove the exhaust system and slide the header pipes forward. This increased effort does have a positive side, it allows me to check the exhaust flanges and renew the anti seize compound.

[Zombie Master]

While you are in there, might as well inspect the check valve. I use a chop stick to press the ball in, to check that it is seated.

[Wobbly]

There are several oil filters for BMW twins...

• The single-piece original oil filter with tight-fitting grommets on both ends of the cartridge
• The hinged oil filter with tight-fitting grommets on both ends of the cartridge (for use on RT and RS models)
• The hinged oil filter with only 1 grommet on one end of the cartridge for use only on oil cooler models

It sounds as if you got hold of the later model filter for use only on oil cooler models. The missing end grommet is what allows oil to travel to the cooler. Using those type filters on a non-oil cooler model will allow oil to by-pass the filter element.

[Kurt in S.A.]

• The hinged oil filter with tight-fitting grommets on both ends of the cartridge (for use on RT and RS models)

Well, really more than that. I use them on my '78 R100/7. BMW doesn't offer the straight filter anymore, although aftermarket folks might.

Kurt in S.A.

[ME 109]

While you are in there, might as well inspect the check valve. I use a chop stick to press the ball in, to check that it is seated.

My spring has broken again, I think due to the damage that was done the first time the spring broke. My bypass cavity is too damaged to just replace the spring so it looks like the bypass will be blocked off.
Careful when poking around in there. PAS, who used to post here broke his spring when poking it. I think it shouldn't have broken and that he may have been lucky that it did break, allowing him to replace with a new spring.
Just be careful. Poke it in a max of 3mm, 1/8"

[jagarra]

I have spring hooks used to work on old NCR mechanical machines so I was able to just slide the old o-ring out. Didn't poke the pressure relief valve. Back together again, ready to ride.
According to Snobum's site, this particular filter was for non oil cooled bikes 78-81. When I ran the current stock number for the filter on real OEM, my number came up as one in the series of filter numbers for the R90/6. I saved the old o-ring we will see if it the same size as the replacements I ordered.

[Kurt in S.A.]

The critical thing is the overall length. Plus the engine cover is different for the /6 versus the /7-on.

Kurt in S.A.

[Airbear]

I have spring hooks used to work on old NCR mechanical machines ...

Whoa, flashback time. I worked for NCR back in the late 60s, with the issued toolkit strapped on the back of my BSA Bantam, servicing those old cash registers. I don't remember much about it - it was the 60s after all - but do remember the spring hooks. I have wanted some just like those ever since. [old fool sighs while staring vaguely into the distant past].

I get my oil filters from Motobins. They have the one piece filters with the black seal at both ends in OEM and 'pattern' types. I use the Mahle OX35s.