[Vwdiesel] Brake boost failure....Update.

[brian gochnauer]

I wouldn't think carbon vanes would be compatible with oil, but maybe.
Did you find whether the vane pumps are supposed to be wet or dry??

Brian

On 12/18/08, mark shepherd <mark at shepher.fsnet.co.uk> wrote:
>
>  Brian,
> When I gave each vane a cursory look, they had no wear on the rounded
> edges, but indeed did have little chips on the trailing face.
> They did seem lightweight, Another look might be in order. Sump pressure
> might be an issue with xs oil getting in the way...
> Mark
>
> ----- Original Message -----
> *From:* brian gochnauer <brian at gochnauer.net>
> *To:* mark shepherd <mark at shepher.fsnet.co.uk>
>  *Sent:* Thursday, December 18, 2008 12:37 PM
> *Subject:* Re: [Vwdiesel] Brake boost failure....Update.
>
>
>  This may help give some insight.
> http://www.mechanicsupport.com/vacuum_pump.html
>
> Aircraft vacuum pumps can be wet (oil bath)  or dry, not sure whether the
> vane area of the VW pump is supposed to be wet or dry.
> I'd make an educated guess and say that dry pumps have carbon vanes and wet
> pumps would have steel vanes.
> check for chatter marks.
>
> On 12/18/08, mark shepherd <mark at shepher.fsnet.co.uk> wrote:
>>
>> OK today's [Thursday] report:
>> Temperature this morning 5 to 10  deg C. Upon starting the car and
>> operating
>> brake, gauge rose to about 5" WG, and then died. Revving engine did
>> nothing.
>> Possibly residue escaping from last night?
>> Vaccuum began appearing within about 1/4 of a mile of yesterday's point
>> [before it].
>>
>> Been good all morning. 'RH Turn' effect may just be nothing.
>>
>> The opened out pump couldn't be simpler; but does any one have an accurate
>> description?
>>
>> For example, apart from centrifugal force, does the oil actually force the
>> vanes apart, or is it just a lubricant?
>> I guess I'll have to run it with the lid off and watch for a fountain :o)
>>
>> Farmer Joe  have you cut one open? LOL
>>
>> Mark
>>
>> ----- Original Message -----
>> From: "mark shepherd" <mark at shepher.fsnet.co.uk>
>> To: "vw fans" <Vwdiesel at vwfans.com>
>> Sent: Thursday, December 18, 2008 3:22 AM
>> Subject: Re: [Vwdiesel] Brake boost failure....Update.
>>
>>
>> >
>> > One further possible quirk noticed just before getting home, is that it
>> > appeared that vaccuum drops 2 or 3 inches when making a sharpish rh
>> > turn!!!
>> > Further investigation needed I think :lol:  Does orientation[ rotation]
>> of
>> > vane pump have any effect upon operation?
>> >
>> > Quantum Bentley $46 delivered to UK. I suppose it is a heavy book. but I
>> > thought we were the 52 state of America ;op
>> >
>> > Mark
>> >
>> > ----- Original Message -----
>> > From: "mark shepherd" <mark at shepher.fsnet.co.uk>
>> > To: "vw fans" <Vwdiesel at vwfans.com>
>> > Sent: Wednesday, December 17, 2008 3:50 PM
>> > Subject: Re: [Vwdiesel] Brake boost failure....Update.
>> >
>> >
>> >>
>> >> Vac  holds  for hours. In fact there may be a residue
>> overnight!  Plenty
>> >> of lubrication in chamber.  This morning ran to town. No vaccuum on
>> >> gauge,
>> >> until driven  a mile or so , and then it returned completely within a
>> few
>> >> seconds. Operates every trip  immediately, and hot  or cold reaches
>> about
>> >> 23 in wg. Problem must be with the vanes somehow.  Temp this morning
>> was
>> >> around zero. Car windows iced yet no ground frost.
>> >> Maybe there is too much oil?
>> >> More pointers please.
>> >> Mark
>> >>
>> >> Sniped  a Quantum Bentley a few days ago  for $6, alas postage may kill
>> >> me
>> >> though!
>> >>
>> >>
>> >> >
>> >>
>> >
>> >
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>> >
>> >
>>
>>
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>
>