[Vwdiesel] Fw: Crankcase ventilation / rotary vacuum pump

[Erik Lane]

Or you could have a 'T' between the cam, the intake, and that block
plate, if it was hard to find a blank cover plate. But by no means do
you want to hook your vacuum line to any of those. The rotary type
exhausts the air into the block through it's drive shaft, I believe.

On Thu, Jul 2, 2009 at 3:28 PM, mark shepherd<mark at shepher.fsnet.co.uk> wrote:
>
> ----- Original Message -----
> From: "mark shepherd" <mark at shepher.fsnet.co.uk>
> To: "Craig Osborn" <cosborn at epix.net>
> Sent: Thursday, July 02, 2009 11:27 PM
> Subject: Re: [Vwdiesel] Crankcase ventilation / rotary vacuum pump
>
>
>> Blank off the sump ventilation and ventilate from the cam cover only. Only
>> the brake servo/booster should attach to the vacc line [maybe some small
>> control lines too eg a/c...]
>>
>> Mark
>> ----- Original Message -----
>> From: "Craig Osborn" <cosborn at epix.net>
>> To: <vwdiesel at vwfans.com>
>> Sent: Thursday, July 02, 2009 11:11 PM
>> Subject: [Vwdiesel] Crankcase ventilation / rotary vacuum pump
>>
>>
>>>
>>> I recently purchased a rotary vacuum pump that was advertised as a bolt
>>> on
>>> replacement for my old diaphragm type vacuum pump on my 1981 PU.
>>> When I started to install the pump I noticed that it only had one hose
>>> fitting whereas the old diaphragm pump had two hose fittings (one on the
>>> top
>>> that went to the brake servo, and one on the side that went to the
>>> crankcase).
>>> I took the car around the block after hooking up the vacuum hose to the
>>> top
>>> fitting without attaching the crankcase hose to anything and I had the
>>> best
>>> braking power that I have had in years.
>>> I then called "Parts Place" to ask what to do about the crankcase
>>> ventilation hose and they said that many of their customers were putting
>>> a
>>> T-fitting on the top and attaching both hoses this way.  When I did this,
>>> my
>>> braking power decreased markedly.
>>> I then took my old diaphragm pump and spun the gear and noticed that it
>>> pulled a vacuum in the top hose fitting but put positive pressure out of
>>> the
>>> bottom fitting where the hose would attach that would go to the
>>> crankcase.
>>> Given this discovery, it seems as though the recommended T fitting would
>>> not
>>> be the proper thing to do.
>>> Can anyone help me retrofit this pump properly on to my 1981?  Maybe
>>> someone
>>> with a 1984 (when they started factory installing the rotary pumps) can
>>> explain how their ventilation system is set up.
>>>
>>> Craig
>>>
>>> _______________________________________________
>>> Vwdiesel mailing list
>>> Vwdiesel at vwfans.com
>>> http://www.audifans.com/mailman/listinfo/vwdiesel
>>>
>>
>
>
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