Rear master cylinder plastic elbow leak.

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sixinoz
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Rear master cylinder plastic elbow leak.

Post by sixinoz »

I have a leak from the plastic elbow on the rear master cylinder. The o ring is a new Honda part and the recess in the master cylinder has been thoroughly cleaned. The o ring seems to sit below the lip of the casting meaning the plastic elbow does not exert any compression on the o ring. Does the o ring seal by being a tight fit in the recess and around the plastic tube? I have bought a slightly thicker o ring to see if this cures the leak but if anyone can comment on this issue it would be appreciated.

steve murdoch icoa #5322
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Re: Rear master cylinder plastic elbow leak.

Post by steve murdoch icoa #5322 »

Are you referring to #20 in this schematic?
Never had a problem with a leak there and it "being a tight fit in the recess".
https://www.ronayers.com/oemparts/a/hon ... r-cylinder

sixinoz
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Re: Rear master cylinder plastic elbow leak.

Post by sixinoz »

Yes - #20. If this o ring does not fit tighly against the recess and the plastic part going thru it, wouldn't this cause a leak?

daves79x
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Re: Rear master cylinder plastic elbow leak.

Post by daves79x »

The o-ring is a tight fit. I don't think you have the correct one. That said, are you sure that's where the leak is? If the bottom hose clamp is not pretty tight, it'll leak there.

Dave

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NobleHops
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Re: Rear master cylinder plastic elbow leak.

Post by NobleHops »

Ya, I tried and failed to use a “close enough” oring there. Pretty sure Honda still sells the oring, I’d start there too.
Nils Menten
Tucson, Arizona, USA '80 CBX, sort-of restored :-)

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