# Brake vacuum pump from VW-AUDI ? Experience?



## azdeltawye (Dec 30, 2008)

Stunt Driver said:


> Anyone tried using automotive vacuum pump like below?
> ....


I'm using this pump in my Jetta. Works great.

As for the switch, I'm using two of these (except the vacuum version):
http://cgi.ebay.com/New-Omega-Minia...tem&pt=LH_DefaultDomain_0&hash=item4ce8e387cf

One switch set for low vacuum alarm and one set to cycle the pump.


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## Stunt Driver (May 14, 2009)

Great news! How loud it is? Have you done any extra silencing/mounting, or is it ok as is?

About that switch you linked - at what vacuum level does it cut in and out, if you know?


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## azdeltawye (Dec 30, 2008)

Stunt Driver said:


> Great news! How loud it is? Have you done any extra silencing/mounting, or is it ok as is?
> 
> About that switch you linked - at what vacuum level does it cut in and out, if you know?


The vacuum pump is no louder than the MR2 power steering pump provided that you use rubber isolation mounts. I found some rubber mounts at McMaster-Carr with M6X1 threads that fit the pump perfectly: http://www.mcmaster.com/#9376k27/=7f1nhs

The Omega PSW-543 vacuum switch is adjustable. I set the alarm switch at 12” Hg and the pump switch at 20” Hg. The hysteresis however is not adjustable and is about 1 – 2”.


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## lou-ace (Jul 21, 2009)

here are links to the pump and switch that I am using. 

 https://www.surpluscenter.com/item.asp?item=4-1801&catname=air

and www. cloudelectric. com ( see switches) 

total $52 dollars for pump and switch. although the pump is rated 135 vdc I'm running it off of my 144v power line with good results.


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## Stunt Driver (May 14, 2009)

lou-ace - good deal on price! Does that mini pump produce enough volume?


*azdeltawye* - I got my pump - i think I ifgured out contacts BUT - sometimes it doesn't start, unless I give it a shake. Just like if brushes would be stopping in a dead position. Still experimeting.

If I reverse polarity - motor doens't run, and so short circuits, haven't see that on DC motors before.

Noise level is infact very acceprable


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## azdeltawye (Dec 30, 2008)

Stunt Driver said:


> *azdeltawye* - I got my pump - i think I ifgured out contacts BUT - sometimes it doesn't start, unless I give it a shake. Just like if brushes would be stopping in a dead position. Still experimeting.
> 
> If I reverse polarity - motor doens't run, and so short circuits, haven't see that on DC motors before...


When you say contacts I assume you are referring to connections. Here is a copy of my notes on the connections for this pump:


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## Stunt Driver (May 14, 2009)

Thank you for pinout!

To eliminate relay faliure - I took it off, and testing motor by applying 12v directly.

Not sure why - i tried reversing polarity, and motor doesn't spin at all - but short circuits. Any idea why?


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## Stunt Driver (May 14, 2009)

Ok, i am getting replacement on pump, but now quesiton on switch:

*azdeltawye* - is your switch pressure/vacuum or vacuum only?
mine has scale marked from 20 to 120, and switch is only triggered by pressure, not by vacuum.

Was I sold the wrong switch?


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## azdeltawye (Dec 30, 2008)

Stunt Driver said:


> Ok, i am getting replacement on pump, but now quesiton on switch:
> 
> *azdeltawye* - is your switch pressure/vacuum or vacuum only?
> mine has scale marked from 20 to 120, and switch is only triggered by pressure, not by vacuum.
> ...


I'm using the Omega PSW-543 which is a vacuum switch. They have other models as well. Check out the list:
http://www.omega.com/Pressure/pdf/PSW-500.pdf


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## lou-ace (Jul 21, 2009)

*Stunt Driver */the pump that i use pumps down the vacume of an opprox. 18"x4" pvc resivoir to 20"hg vac in about 2 seconds and seems to work fine for my braking needs. I dont hear it while driving. I'm not sure exact. what the cfm is on the pump but it workd well for my small ( ford ranger) truck application. good luck.


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## Stunt Driver (May 14, 2009)

Still looking for a vacuum switch.

found those EVAP switches - who knows what is their trigger vacuum level?
http://cgi.ebay.com/ebaymotors/1997...temZ200466382430QQptZLHQ5fDefaultDomainQ5f100


*Lou-Ace* - you gave link to pump, but switch is not there. do they still sell it?


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## Stunt Driver (May 14, 2009)

progressing.

Got new pump - it is very quiet, you can only hear it if car is not moving, and it's not even mounted so far.

Got Omega pressure switch, and converted it to vacuum switch - just unscrewed switch's head couple of threads. It is adjustable, so I will be setting it to trigger once nearly maximum vacuum reached.

Next - need to build reservour.


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## Stunt Driver (May 14, 2009)

here is one of the latest ebay offers. Have to say all the cheap options are gone, but keep watching!!

Search line to get right ones from thousands of ebay items: *vacuum pump electric vw*


Again, don't be shy on offering your price, like $50 plus shipping. I had mine accepted!


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## tomofreno (Mar 3, 2009)

> Next - need to build reservour.


Is a reservour necessary?
How did this pump/switch work out?


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## Stunt Driver (May 14, 2009)

I used one of these at the end
http://www.omega.com/manuals/manualpdf/M1395.pdf

by mistake I purchased pressure switch, not vacuum. BUT - It is fully adjustable, so with a little trick - I made a vacuum switch out of pressure by shifting membrane head a couple of threads in.

Will post pics tomorrow hopefully - I used no reservour. I have enough pressure to slam on brake and block wheels. Don't feel any discomfort.


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## tomofreno (Mar 3, 2009)

What relay did you use? The pump I have (HAD I guess, since it no longer works) has a 40A fuse, so would require a relay that can handle that large of DC current. Don't know what amperage the Audi pump uses.


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## Stunt Driver (May 14, 2009)

I have connected my to radiator FAN harness, and vacuum switch connected to native FAN relay thru native fuse. So I didn't add much to integrate pump in car.

Attached are some pics


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## PROFGOBELI (Mar 25, 2008)

*Re: Brake vacuum RESERVOIR*

In regards to vacuum reservoir, the power brake booster holds enough vacuum for at least one complete stop, in DOT legal vehicles, with ICE off (after running of course)!


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## hendrik6073 (Oct 29, 2010)

Stunt Driver said:


> by mistake I purchased pressure switch, not vacuum. BUT - It is fully adjustable, so with a little trick - I made a vacuum switch out of pressure by shifting membrane head a couple of threads in.


Hi do you have some more information on this part ? is it still ajustable after the trick ?

i see the price of 20+$ for a pressure and 88$ for vacuum. So if this works......


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## brainzel (Jun 15, 2009)

I use this vaccum-pump (out of an audi A6) to stop my New Beetle.
Very simple connection 12V (key switch) and ground and it starts sucking.
To let it only run if it's needed, connect a underpreasure switch between it.
I use a Festo VPENV-PS/O-S-L-GH 152706.

The pump starts by turning the key and stops at the adjusted underpreasue.
If you break, it will start again. I don't hear it, and it works great.
I bought one on ebay for $40 US Dollar. Connections and switch costs another $30 dollars.

Here is my Blog post about it (in german): e-beetle.de


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## hendrik6073 (Oct 29, 2010)

Okay, i use the Hella UP28 pump. The switch u use, is it ajustable ? at what vacuum does it switch off youre pump ?

thanks

Richard


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## brainzel (Jun 15, 2009)

Yes Richard, the switch has two little screws (I added a picure) to adjust the pressure.
I can't see the data of the appointed pressure. I turned it to maximum, waited 6 seconds and then turned the screw slowly down so the pump stopped. 200km (125miles) driven around and everything works great.


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## hendrik6073 (Oct 29, 2010)

okay, i did take a look at you're site also, looks great. I ordered a switch on ebay. So with some luck i can test this by myself.

thanks !


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## hendrik6073 (Oct 29, 2010)

i got the switch. so maybe next week i am gonna try it out.
wat kind of connector did you use on the little electric pins ? did you solder this ?

thanks


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## ahambone (Jan 13, 2009)

I just got one of these pumps for my Cabriolet conversion. The Benz pump I was using was embarrassingly loud (like head-turning loud). On the bench this little guy seems to spin right up and hum away and draws much fewer amps than the beast I have currently installed. 

Mine came with the control relay attached. I could remove the relay and get to the +/- terminals on the pump directly, which works fine. It also has a 3 pin interface where the right solo pin is (+) the left pin parallel to the right pin is motor ground and the other pin is relay (-). Apparently a low-current pressure switch can be used to drive the relay. I already have a relay in my system but I like the attached relay more so I think I'll reconfigure my system to make use of the relay attached to the pump. For ~$70 this is a pretty sweet pump - getting the relay with it was just icing on the cake.

I'll post an update and maybe some pictures when I get this one working. Thanks for the suggestion on the part! 

Cheers,
--Adam


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## hendrik6073 (Oct 29, 2010)

i use a standard M8 4 pin connector to connect te switch . I grinded some of the outside thread of the connetcor to get a tight fit. One of these days i gonna put hte parts toghether to test.


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## omonoid (Aug 30, 2009)

Im really considering using this method for my brakes because it seems like it is quieter, cheaper and simpler than other more standard approaches.

I would really appreciate if someone who has done this could summarize how well it works and give me a list of what i need to get it running. It seems confusing to me

Thanks


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## brainzel (Jun 15, 2009)

I thought I explained it well in Post #21 ... I couldn't get better words for it, sorry 

All I can add is: yes, it is quiet; yes, it wasn't expensive; yes, it was easy to install.
If you want to use it in your VW Golf II, it will surely fit easy to your brake power assist unit.


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## nosmanta (Jul 24, 2011)

azdeltawye said:


> I'm using the Omega PSW-543 which is a vacuum switch. They have other models as well. Check out the list:
> http://www.omega.com/Pressure/pdf/PSW-500.pdf


Hi!

I'm doing this brake mod for my Subaru and was wondering if you can tell me which wire for the PSW switch goes to 12V+ and negative. 
There's 3 wires, white ,black and red. Appreciate any help. Thanks!

kind regards,

Mario


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## azdeltawye (Dec 30, 2008)

nosmanta said:


> Hi!
> 
> ... which wire for the PSW switch goes to 12V+ and negative.
> There's 3 wires, white ,black and red...


The Omega PSW series vacuum switches has a 'form C' contact arrangement: red = normally open, white = normally closed, black = common

If using this switch with the Audi/VW pump connect the normally closed contact to pin 2 on the pump and ground. See post #7 on this thread for pump pin-out.


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## nosmanta (Jul 24, 2011)

azdeltawye said:


> The Omega PSW series vacuum switches has a 'form C' contact arrangement: red = normally open, white = normally closed, black = common
> 
> If using this switch with the Audi/VW pump connect the normally closed contact to pin 2 on the pump and ground. See post #7 on this thread for pump pin-out.


Thanks for the quick reply! I'm using a VW/Audi pump but with 2 pins only. Positive and negative. So I will connect the white wire to the pump and ground. How about the red (NO) and the black(common) wires? Thanks again!

regards,

Mario


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## Conelrad (May 23, 2009)

Ford Super-Duty 4X4 pickups around the 2005 years have a little electric vacuum pump for operating the transfer case.

I have not tried it for braking service, but it looks beefy enough. Was $75.

DG


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## 9852 (Jan 17, 2010)

Conelrad said:


> Ford Super-Duty 4X4 pickups around the 2005 years have a little electric vacuum pump for operating the transfer case.
> 
> I have not tried it for braking service, but it looks beefy enough. Was $75.
> 
> DG


yep, i used that one in my neon conversion, it worked good but it was a little loud.


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## azdeltawye (Dec 30, 2008)

nosmanta said:


> ...I'm using a VW/Audi pump but with 2 pins only...


If you're using a pump without an internal switching circuit (only two pins) I would use an auxillary relay to control the pump. The Omega switch contacts are probably not rated for the full load of the vac pump.


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## ElectriCar (Jun 15, 2008)

I have manual brakes now so I only need vacuum to operate the ventilation controls. Just wondering which pump you guys would recommend for that. I had a Thomas and removed it after converting the brakes. I know the brakes before would suck most of the vacuum and I could brake twice before the pump came on. The vents would take about 3 or 4 operations before the pump came on.

I'm liking the design of brainzel's Audi pump but would like to have the connector for it. Those look like ones I used to purchase from Newark Electronics in the US.


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## notailpipe (May 25, 2010)

Stunt Driver said:


> I have connected my to radiator FAN harness, and vacuum switch connected to native FAN relay thru native fuse. So I didn't add much to integrate pump in car.
> 
> Attached are some pics


Stunt Driver, how did you mount this vacuum switch into your brake reservoir directly? ICE cars should always have a vacuum and so I don't see why they would have tapped a hole in there for any switch. Did you drill your own hole into it and tap it out? 

Thanks.


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## notailpipe (May 25, 2010)

Hi guys.... so I got this pump hoping it'd be quiet and it's like embarrassingly loud! Am I doing something wrong?

I've got it mounted on a vibration damper made for electronics parts, and that itself is mounted to my motor mount, which I thought would give more damping since I kept the rubber. 

Are you guys using a muffler or anything? There's a little outlet port that blows out air when it's pumping, wondering if I can put something on that, or maybe shroud the whole thing in some sort of noise dampening cloth?

I'm just really frustrated cause the rest of my car is super quiet and then when I show people the car it's like <BLAAATTT! silent silent BLAAAAT!!> and really obnoxious.  Was really hoping it'd be quiet. 

Any ideas what I might be doing differently that everyone else's is quiet as a churchmouse?


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## ElectriCar (Jun 15, 2008)

I converted mine to manual brakes so I could eliminate that horrendously obnoxious noise. Now my AC system can't switch between vent, floor & defrost etc. But all I need now is a very small hopefully low noise vacuum now to fix that. I was thinking of that same pump myself. So it's not quiet huh? 

You might place some of that egg crate looking sound dampening foam around it but that still leaves the exhaust port which a muffler on mine didn't do much to quiet down.


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## notailpipe (May 25, 2010)

Anyone else have any thoughts on how your VW/Audi pumps are quiet? 

I tried muffling mine with some insulation tape and foam. Not surprisingly (in retrospect, I feel kinda stupid for even trying this), it was seriously overheating when running. I was running it always-on (in the middle of getting a vacuum switch), so maybe this wasn't designed to run constantly. Does anyone know in the original VW/Audi cars is this not running full time? If so then shouldn't we also be able to buy a cheap VW/Audi switch to go with it? I have since been assuming that it's running fulltime and the "/ON" enable input just comes from the ECU and turns on with ignition.

Did I just get a bad pump that mine is so loud?
Anyone else able to run fulltime instead of intermittent?


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## dtbaker (Jan 5, 2008)

hhmmm, my Gast pump is actually pretty quiet, and comes on only every third brake application. runs about 15 seconds and holds vacuum 'indefinitely' until after I hit the brakes three times. you can hear it, but its just kind of a 'bbbrrrrrrrrrrrrr'....

you can see it here.... clamped to the PVC conduit I ran from motor bay back to rear batteries. So it is NOT bolted to firewall or fender.... semi-isolated from solid mounting that might vibrate seemed better.


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## mk4gti (May 6, 2011)

Anyone have a VW or AUDI part number for the pump ?


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## notailpipe (May 25, 2010)

mk4gti said:


> Anyone have a VW or AUDI part number for the pump ?


This thread has it, but just eBay it and they all look similar.


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## azdeltawye (Dec 30, 2008)

notailpipe said:


> Anyone else have any thoughts on how your VW/Audi pumps are quiet?





notailpipe said:


> ……
> Did I just get a bad pump that mine is so loud?
> Anyone else able to run fulltime instead of intermittent?


I think that the VW/Audi pump which I am using has an acceptable noise level. I can hear the pump kick on while sitting at a traffic light. But once above 20mph or so the road noise drowns it out. 

You need to make sure to properly isolate the pump from your car body. If any part of the pump is in contact with the car body it will amplify the noise of the pump significantly. 

I found sandwich style rubber isolators from McMaster Carr with a M6 stud that bolted right to the pump. These mounts are fairly soft with a durometer rating of 50a. The harder the material used for isolating, the louder the noise will be.

These pumps are not designed to be run continuously.


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