Oily cutoff valve
knotnook at traverse.com
Tue Aug 3 18:54:59 EDT 2004
Thanks, Phil. Hose is new and rerouted away from the turbo to the
passenger fender. Gauge shows 1.6 and occasionally 1.7 at appropriate
times. Besides, dying stopped with the new valve in place.
I've not had an exceptionally oily Michelin Man hose, like pooling in the
lower folds, as described in the archives. Just coatings of oil, which is
what I saw this time.
At 05:58 PM 8/3/2004 -0400, Phil Rose wrote:
>At 5:00 PM -0400 8/3/04, Kneale Brownson wrote:
>>I replaced my overrun cutoff valve
>My test for BPV "goodness":
>(1) Use Mity Vac on the small nipple to operate the valve--showing
>it can be opened and will hold a vacuum indefinitely. (2) Test that
>neither of the large nipples will permit flow of air when valve is
>closed (both ports should hold tight under moderate positive and
>negative pressure). This is easily done "orally".
>>Anyway, I noticed that the one I took off had oil on it just like the
>>inside of the Michelin Man hose gets. Is that normal? I didn't remember
>>the other one being oily last spring.
>The ones I've inspected/rejected have been _somewhat_ oily, but not
>with significant amount of liquid (as compared with the typical
>>What fails on these things, anyway?
>They usually develop a tear in the thin, flexible plastic bellows
>material (valve). This will cause the valve to fail to open when
>under manifold vacuum. Of course you're aware of the propensity for
>the small vacuum/pressure hose to become brittle and blow apart),
>which causes an otherwise good valve to be inoperative (and also
>allows boost pressure to leak). I believe that both defects (torn
>valve bellows and the torn hose) can produce the same stalling
>symptom--independently. So best not to replace the valve until the
>hose is verified to be OK.
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