Servicing disc type breather.

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Garnet
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Joined: Tue Aug 03, 2010 6:24 pm
Location: Victoria BC Canada

Servicing disc type breather.

Post by Garnet »

My 72 R75/5 winter beater needs it's breather serviced. It seems to be leaking from the front and rear main seals which are new, plus I also blew out a valve cover gasket, which I have never seen happen before.

Most articles on this subject say to simply replace the disc style breather with the later reed valve version.

Has anyone out there used an automotive PCV in place of the breather?
Garnet

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Kurt in S.A.
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Re: Servicing disc type breather.

Post by Kurt in S.A. »

Not sure they'd fit under the housing. Why go out of your way when a decent drop-in part is readily available??

The old disk can be replaced with a similar dimensioned piece of PC board. Oak Okleshen used to do that a lot...I believe he doesn't have any more of the disks. They are 27mm in diameter. The hole in the middle is a #2 size drill bit.

Kurt in S.A.
Garnet
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Joined: Tue Aug 03, 2010 6:24 pm
Location: Victoria BC Canada

Re: Servicing disc type breather.

Post by Garnet »

Kurt in S.A. wrote:Not sure they'd fit under the housing. Why go out of your way when a decent drop-in part is readily available??

Kurt in S.A.
Cuse I'm cheap......................
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00weel
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Re: Servicing disc type breather.

Post by 00weel »

Garnet wrote:
Kurt in S.A. wrote:Not sure they'd fit under the housing. Why go out of your way when a decent drop-in part is readily available??

Kurt in S.A.
Cuse I'm cheap......................
A true Airhead enthusiast embracing his inner cheapness!

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standswithabeer
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Joined: Wed Aug 18, 2010 8:23 am
Location: southern vt

Re: Servicing disc type breather.

Post by standswithabeer »

the breather disc is held shut by little, weak coil spring. is yours stuck shut, building sufficient crankcase pressure to blow out your front and rear main seals and valve cover gasket? wow.
76 r75/6
96 ducati 900ss/cr

a bike nut since '69 or so
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mattcfish
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Re: Servicing disc type breather.

Post by mattcfish »

standswithabeer wrote:the breather disc is held shut by little, weak coil spring. is yours stuck shut, building sufficient crankcase pressure to blow out your front and rear main seals and valve cover gasket? wow.
Actually I believe if the valve is stuck open the engine will actually suck in more air than it pushes out, thus increasing crank case pressure dramatically. I doubt a valve can stick shut.
Bellingham, WA USA
1975 BMW R90/6
1975 BMW 2002
1971 VW Westfalia
1985 VW Vanagon
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