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Re: [EVDL] Electric Pump for Power Brakes (was Another EV(Ranger)Grin!)

If you're driving w/o vacuum boost, then any vacuum boost would be
I've heard that you need 15-25 (pounds? Hg) of vacuum.

I got a tiny vacuum pump off ebay, from a Superduty Ford diesel for $65;
it pulls 15 Hg of vacuum, does it quickly, and is really quiet.

A friend is using a Schuco 138 Dental aspirator pump that runs of DC; he
got it for $40 (plus shipping). It pulls 23-25 Hg of vacuum.
My friends' schuco pump does really well...

It runs for about 10 seconds whenever he "cranks up" his vehicle, then
goes quiet.... you can hear it quietly thumping away for those few
seconds.. which is a neat indication to guests that the truck is "on" and
ready to go! When it turns off, they think something is wrong, and want
to "start" it again! (its funny to see!)

I wanted to try a 'door lock' vacuum pump from a BMW or Mercedes, but I'm
not sure how much vacuum it pulls.

EV Parts has a small $23 vacuum cut-off switch that you can use to turn
these things off and on, so they don't run all the time; its adjustable.

You should pick up a vacuum reservoir and vacuum check-valve from
Pull-A-Part, or any salvage yard - from an old vehicle.

You can generally get both of these items for about $5.00. The reservoir
on some GM models is a little bit larger than a softball.

Then, when you use the brakes, even if your pump can't provide all the
vacuum you need immediately, the reservoir will provide the vacuum you
need, and the pump you choose can 'recharge' it with vacuum. Additionally,
when the pump turns off, the check-valve will prevent it from having to
start up with a vacuum on it; so if it leaks a little, the vacuum will be
saved, and the pump can start up 'easily' without having to start up with
a vacuum on it already -

You'll need 2 T-connectors:

So hook the hoses up like this:
Vacuum Pump->Check-Valve->4-way connection->Vacuum reservoir
+->Vacuum Switch
+-> Brake Booster

I'm still trying to figure out how to mount my 'component board' under
the hood (controller, heat-sink, contactor, etc) - I've been somewhat lazy
in not working on it like I should...

I'm afraid to drill holes in the firewall - what with all the goodies back
there. I'm afraid I'm going to have to take the dash half-apart in order
to get some mounting brackets on it, w/o drilling into the AC
heat-exchanger, or other elecrical goodies....

(Feel free to berate me for not getting my duff in gear, and finishing
this project!!)

Best Regards -

Ed Cooley

"Roland Wiench" <[email protected]>
Sent by: [email protected]
09/19/2007 12:50
Please respond to
Electric Vehicle Discussion List <[email protected]>

"Electric Vehicle Discussion List" <[email protected]>

Re: [EVDL] Electric Pump for Power Brakes (was Another EV(Ranger)Grin!)

----- Original Message -----
From: "storm connors" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Wednesday, September 19, 2007 9:23 AM
Subject: Re: [EVDL] Electric Pump for Power Brakes (was Another EV

> I suffered the sticker shock as well. I bought it after buying a GM unit
> that turned out to be no good. I don't think there has been anything on
> the
> EV that didn't cause sticker shock. I rationalize it by considering what

> it
> would cost to build a Buick from the parts counter.
> > Just checked out Summit Racing and their electic Vacuum Pump for
> > brakes. Wow, $330 for the kit not counting shipping and any taxes?
> > That's
> > a bit higher than I was expecting. I was considering a used pulley
> > vacuum
> > pump, electric motor, pressure switch and reservoir. I was budgeting
> > around
> > $150 or so for the all the parts. A kit offers one-stop shopping with

> > most
> > of the labor already done for you but the sticker shock still lingers!
> >
> > Since driving my EV around town I'm becoming quite good at stopping
> > lots of pressure. I haven't resorted to both feet yet (as Bob Rice

It is best to set up a relationship with a independent auto parts dealer
you can fine one. I been going to the same auto parts store for now about

47 years now. These type of dealers can get you any type of part made
who ever you want.

Also a Auto World store is a good one that has these type of performance
parts, that I also use on a EV.

I purchase a belt driven GMC vacuum pump from them for about $80.00 which
was listed at about $150.00 at the GM dealer. I did all the leg work, find

out what the part number is, and make the supply run with a purchase order

from the auto parts store to pick up the item.

Then for a motor, get a 12 volt motor from Summit or Jegs that is about
$55.00 or you can get the motor, with mounting brackets, pullys and etc
about $80.00.


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