I was pretty excited this afternoon when I picked up my 70 Chevelle from the engine builder. However, when I took it for a test drive I got a bit of a surprise.

I just finished converting to power disk brakes prior to having the engine blue printed and balanced and the heads ported and polished. Apparently the cam the builder selected has left me a little short on vacuum. Although the engine really performs I no longer have power disk brakes.

Can anyone recommend a vacuum pump I can bolt up to get my power brakes back? I saw a couple posts from guys with similar problems in the past but can’t locate them on the forum.

I need to know whats available and if I should use a mechanical pump or electric and where I can find one of those beasts. I don’t know if it makes any difference but I converted to a serpentine pulley system when the engine was out.

Thanks in advance

Brad Howard
1970 Chevelle
BB 402

Brad boy man are you in luck, I just have few more things to do and my system will be ready to test drive in, its already up and running I just have to trace a very small leak. Well, here is what I did based off of reading up what everyone seems to recommend then picking and choosing parts accordingly. The pump i bought is a Gast mfg. part #:22D1180-201-1002 that's the old part number i got off the web site i think the new number changes one number to a 5 if i am correct, that is the one i have here is a spec on the pump http://www.gastmfg.com/pdf/mini/specsht/22d.pdf
This pump came highly recommended and i saw one in use on a booster at a local speed shop before purchasing, I ended up buying the pump from

Brenner-Fiedler & Associates
13824 Bentley Place
Cerritos CA 90703-2434
Ph: 800.843.5558
562.404.2721
Fax: 562.404.7975
www.brenner-fiedler.com/ (http://www.brenner-fiedler.com/)
e-mail: sale@brenner-fiedler.com

Retail on it was like $160 bucks, I bought it threw my business for right around $140 their shipping was super snappy, they were very helpful and the only place that had it in stock, I would highly recommend them. The second part I bought was an adjustable vacuum switch from www.mscdirect.com (http://www.mscdirect.com) Part #: 56499197 NASON VACUUM SWITCH, cost was around $40 bucks switch works great I have my system setup so it comes on when the vacuum drops to 17 and turns off at 22 inches, MSE was also very quick on shipping. You will also need a standard headlight relay which i got from my car alarm installer for the great price of free. After getting all this I thought ahead, I wanted to have the engine vacuum as back up just in case the pump ever decided to ever die, so I looked all over and ordered up one of these http://www.usplastic.com/catalog/product.asp?catalog%5Fname=USPlastic&category%5Fname=Check+Valves&product%5Fid=Check+Valves+for+Vacuum

which I'm waiting on reciving and can report how it works

Now for how this thing is hooked up. Vacuum from the pump come off splits into a y, one goes to the vacuum switch the other heads off behind the fender to another junction, it runs to my vacuum gauge (optional) the one line coming from the pump, one to the booster and one (plugged right now pending the check valve order) to the vacuum source on the motor with the check valve inline.

rely wiring is as follows

ground
ign hot
power (to the C on the vacuum switch)
and one to the battery positive terminal

The positive wire from the motor goes to the NC on the switch nothing hooks to the NO... Ground out the black pump wire and your home free. Oh yea, something that took me a while to figure out, when you get the vacuum switch it appears as a sealed unit and no way to ajust, there in a platic plug in the center of where all the wiring hookups are, its in there very tight but you need to pry it out then there is a screw that ajusts when the switch comes on and off. All the Hose barbs splitters and such came from my local Hardware store

Any questions? :D

Tom:
Today is my lucky day. First because there are folks like you on the forum that will take their time and share the information they have gathered with the rest of us. Second, because of your detailed post, locating the parts and restoring my power brakes should be a breeze.

Thanks again for taking your time and posting such a complete solution to my problem. I am sure there are others that will use this information in the future.

Brad Howard
70 Chevelle
BB 402

Not a problem, glad I could be of some help. Let me know if you have any problems or questions. Happy turkey day

Big Thanks from me too!I am also in the same boat.

I woud recommend the GM Vacuum pump from a mid-80's x-body car (82-84 Citation, Cadillac Cimmaron). I got 2 of them from the bone yard for $20 and they work great. Just plumb them in line and they turn on/off as needed and provide 17+ psi of vcuum for brakes. Get the isolated mounting bracket when you get the pump. in front wheel well (follow brake vacuum line from brake booster that goes into the front of the fender) See this link: http://www.gmcmotorhome.com/tech/vacuum_pump/index.html

I am running the stainless steel brakes kit in my 68 k2500 works good, but I got an adjustable vac switch
the lines are also 1/2"