Author Topic: AAZ Vacuum Pump (Rotary) What should it pull?  (Read 3013 times)

May 02, 2012, 04:45:55 am

Syncroincity

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AAZ Vacuum Pump (Rotary) What should it pull?
« on: May 02, 2012, 04:45:55 am »
Anyone have a good idea of what sort of vacuum an AAZ pump should be pulling?
I put a vac gauge on mine, at idle I see about 5" hg, and it climbs commensurate with the RPMs.

Reason I ask is my brake booster is not functioning at all, really have to stomp on the pedal to get brake actuation,
I'm wondering if the pump is weak, or if I have to chase the hose for leaks.

I was looking on EBay and saw lots of ads for electric brake booster pumps for VW/Audi, I was thinking this might not be a bad idea for the van.
I'd have to rig up a better switch tho, the ones on the van now are fluid pressure activated, seems there would be a bad dead spot...
I sort of want to do this anyway, have a pedal switch that makes contact as soon as I touch the pedal; the pressure switch introduces a lag in the brake lights
coming on too.
JC McCavitt
'86 Syncro GL Camper AAZ
'98 Jetta Wolfie
'04 Passat Variant GLS 4Mo 5MT

Reply #1May 02, 2012, 06:35:05 am

libbydiesel

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Re: AAZ Vacuum Pump (Rotary) What should it pull?
« Reply #1 on: May 02, 2012, 06:35:05 am »
It should pull double what you're seeing at idle.  Good oil supply?  Bushing in the right way?  Seal in the bottom of the gear in good shape?
« Last Edit: May 02, 2012, 06:40:05 am by libbydiesel »

Reply #2May 02, 2012, 07:45:36 am

wdkingery

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Re: AAZ Vacuum Pump (Rotary) What should it pull?
« Reply #2 on: May 02, 2012, 07:45:36 am »
i found i have the same brake pedal if my vacuum line to the HVAC unit falls off the vacuum pump; i would check for vacuum leaks, and i would vote your pump is likely still good