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

mark shepherd mark at shepher.fsnet.co.uk
Thu Dec 18 19:06:51 PST 2008 

Ah...
 As I've mentioned before, between inline valve and servo/booster, it 
basically holds, but where I'm measuring, the little barbs, vacuum lasts 
only a minute. So there must be a leak, that matters. There must be a 
second[third  in total] oneway valve in the pump. Is it imbedded below the 
gauze in the 'drive shaft'? ... It must be nest pas?  If that was 
clogged...H'mm as long as the vanes seal on the lid, and the large barb 
seals, wouldn't pump still work? Maybe its the slightly leaking large barb? 
Tomorrows going to produce answers I hope, or at least after Saturday's 
morning start.
Thanks for your help; it's nice to have a mystery to solve...
Mark

----- Original Message ----- 
From: "brian gochnauer" <brian at gochnauer.net>
To: <vwdiesel at vwfans.com>
Sent: Friday, December 19, 2008 2:45 AM
Subject: Re: [Vwdiesel] Brake boost failure....Update.


>
> It's a vacuum pump, if the shaft seal is bad, wouldn't it just 'suck' the
> oil in.?
>
> On 12/18/08, mark shepherd <mark at shepher.fsnet.co.uk> wrote:
>>
>> I'm sure the problem points to sticky vanes. If it is the oil, then I
>> wonder
>> if it's a residue buildup over a period  of time, or, an increase in sump
>> pressure creating an excess of oil?
>> I will give the vanes a clean. My sump pressure is significant, but with
>> increase in revs all but dissappears, which makes me feel rings not all
>> that
>> bad., and not noticeably changed since last gasket change 6000 miles 
>> ago...
>> If the pumps wear, then I assume vane faces would wear a little and slide
>> easier if operation based on centrifugal forces. H'mm the arrows are
>> pointing to sticky residue, releasing when warm...
>> I'll clean tomorrow [today].
>> Mark
>> ----- Original Message -----
>> From: <decker at toledotel.com>
>> To: "mark shepherd" <mark at shepher.fsnet.co.uk>; "vw fans"
>> <Vwdiesel at vwfans.com>
>> Sent: Thursday, December 18, 2008 4:09 PM
>> Subject: Re: [Vwdiesel] Brake boost failure....Update.
>>
>>
>> >
>> > Hi Mark;
>> >    I have never had a problem with a vane pump. I grab one whenever I 
>> > can
>> > find one. The diaphragm pumps work but even when rebuilt seem to be a
>> > problem later down the road. I have never taken a vane pump apart 
>> > because
>> > I
>> > have never had one fail. I would think that unless one is just plain 
>> > worn
>> > out the only thing that might cause a problem is sticking vanes. 
>> > Perhaps
>> > taking it apart and cleaning it in carburetor cleaner or a hot tank 
>> > might
>> > help. I'm completely shooting in the dark since in my experience they
>> > always
>> > work. If any of my friends find out that I have bought a parts car with
>> > one
>> > in it they practically fight over the silly thing
>> > Brian Decker
>> > Western Washington
>> > ----- Original Message -----
>> > From: "mark shepherd" <mark at shepher.fsnet.co.uk>
>> > To: "vw fans" <Vwdiesel at vwfans.com>
>> > Sent: Thursday, December 18, 2008 4:07 AM
>> > Subject: Re: [Vwdiesel] Brake boost failure....Update.
>> >
>> >
>> >> 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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>> >
>> >
>> >
>>
>>
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