solution to power brakes for engines with "lumpy" cams - The 1947 - Present Chevrolet & GMC Truck Message Board Network

snipescastle2 · 05-02-2016, 11:57 AM

Hello all! I just wanted to share an idea I got from the internet. I read where Audi A4's and a lot of Volkswagen cars had electric Vacuum pumps for their vacuum assisted brakes.
I visited my local Pick n pull yesterday after work, found one on a 2003 Audi
A4, paid $26.00 and headed home. I brought it into work this morning, cut the hose barb off the business end, threaded it for 1/8" NPT and hooked up a vacuum gauge, then connected the leads to one of my De Walt batteries to test it, this little Sucker (Pun Intended

) made 25" of Vacuum without breaking a sweat! I'm making a bracket to mount on the firewall and once I have it installed and tested, I'll let you know the results. I took a couple of pics to show my test, but they must be queued up on the mail server at work, so I'll post after while.
Have a good one!
Ben

davepl · 05-02-2016, 12:15 PM

Cool! I guess the only downside would be how often it can make enough vacuum to satisfy the brakes.

Heck that's a cheap source for a vacuum pump in general, I'm sure I paid a lot more than that for one to vacuum down my AC system!

**MikeB** · 05-02-2016, 12:40 PM

Will be interesting to see if it works. I guess it will depend on how much the booster volume decreases the vacuum when brakes are applied.

Dave, an AC vacuum pump needs to pull 29" vacuum to boil moisture at temperatures less than 80 degrees F, so they typically cost more. The really good (and expensive) ones will approach or exceed 29.9".

GMC Canuck · 05-02-2016, 01:47 PM

Maybe with a canister if the pump doesn't have the volume.
Interested to hear how it works.
Will the pump run all the time?
How noisy is it?

AirSpeed · 05-02-2016, 02:02 PM

I bought a gm vacuum pump, tank and vacuum switch on Amazon, made an aluminum mount on my cnc and mounted it to the firewall, it really works great! Get about four stops before the vac pump turns on. Very happy with it!

cleszkie · 05-02-2016, 03:44 PM

Does that have a pressure regulator built in? It should only cycle occasionally when the vacuum goes below a certain limit. It should also stop when the max vacuum is achieved. Otherwise, that pump will wear out from continuous use.

AirSpeed · 05-02-2016, 03:58 PM

Quote:

Originally Posted by cleszkie

Does that have a pressure regulator built in? It should only cycle occasionally when the vacuum goes below a certain limit. It should also stop when the max vacuum is achieved. Otherwise, that pump will wear out from continuous use.

Mine came with an external adjustable vacuum switch. After about 3 or 4 stops it runs for around 20/30 seconds. I tested mine one day during some stop and go traffic and after about 45 minutes of driving it was still pretty cool. You really need a vacuum tank to make it work properly. I had to turn mine down or the brakes got really sensitive.
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AirSpeed · 05-02-2016, 04:04 PM

Quote:

Originally Posted by GMC Canuck

Maybe with a canister if the pump doesn't have the volume.
Interested to hear how it works.
Will the pump run all the time?
How noisy is it?

Mine is pretty quiet, the only time I hear it is at an idle, it's a nice humming sound, not annoying at all. It has rubber bushings to help quiet it down, I mounted it to the right of my brake booster so it's pretty close to me.
Posted via Mobile Device

snipescastle2 · 05-02-2016, 09:13 PM

Out in the open it's kind of noisy, but I think once it's installed and plumbed up to the tank and booster shouldn't be too noticeable. Here is a couple of pics...
Ben

snipescastle2 · 05-02-2016, 09:17 PM

Another...

CST10 · 05-02-2016, 09:45 PM

Sweet idea. Thanks for sharing.

AirSpeed · 05-02-2016, 10:10 PM

Quote:

Originally Posted by snipescastle2

Out in the open it's kind of noisy, but I think once it's installed and plumbed up to the tank and booster shouldn't be too noticeable. Here is a couple of pics...
Ben

Mine was noisy before I mounted it but it's a nice purr now. Yours looks a lot like the one I bought.
Posted via Mobile Device

snipescastle2 · 05-27-2016, 04:59 PM

well, I have yet to try it out, but I did get an adjustable vacuum switch, cycles the pump on at 18 inches of vacuum, just haven't had time to test it out on the truck yet. I made a Vacuum accumulator out of a 5 pound oxygen bottle, couple that with all the braided hose I should have quite a good vacuum supply.....

Ben

05-02-2016, 11:57 AM	#1
snipescastle2 Registered User Join Date: Mar 2009 Location: WARRENSBURG,MISSOURI,64093 Posts: 1,518	solution to power brakes for engines with "lumpy" cams Hello all! I just wanted to share an idea I got from the internet. I read where Audi A4's and a lot of Volkswagen cars had electric Vacuum pumps for their vacuum assisted brakes. I visited my local Pick n pull yesterday after work, found one on a 2003 Audi A4, paid $26.00 and headed home. I brought it into work this morning, cut the hose barb off the business end, threaded it for 1/8" NPT and hooked up a vacuum gauge, then connected the leads to one of my De Walt batteries to test it, this little Sucker (Pun Intended) made 25" of Vacuum without breaking a sweat! I'm making a bracket to mount on the firewall and once I have it installed and tested, I'll let you know the results. I took a couple of pics to show my test, but they must be queued up on the mail server at work, so I'll post after while. Have a good one! Ben __________________ "Persistence is the twin sister of Excellence.one is a matter of quality,the other, a matter of time" “Serious Black” my 1971 Short Bed Fleetside Sold to an outstanding man in Lees Summit,Mo. “Gone, but by no means,Forgotten”

05-02-2016, 12:15 PM	#2
davepl Registered User Join Date: Aug 2006 Location: Redmond, WA Posts: 6,332	Re: solution to power brakes for engines with "lumpy" cams Cool! I guess the only downside would be how often it can make enough vacuum to satisfy the brakes. Heck that's a cheap source for a vacuum pump in general, I'm sure I paid a lot more than that for one to vacuum down my AC system! __________________ 1970 GMC Sierra Grande Custom Camper - Built, not Bought 1969 Pontiac 2+2 427/390 4-speed Coupe 1969 Pontiac 2+2 427/390 4-speed Convertible

05-02-2016, 12:40 PM	#3
MikeB Senior Member Join Date: Jul 2000 Location: North Texas Posts: 3,475	Re: solution to power brakes for engines with "lumpy" cams Will be interesting to see if it works. I guess it will depend on how much the booster volume decreases the vacuum when brakes are applied. Dave, an AC vacuum pump needs to pull 29" vacuum to boil moisture at temperatures less than 80 degrees F, so they typically cost more. The really good (and expensive) ones will approach or exceed 29.9". __________________ Mike 1969 C10 LWB -- owned for 35 years. 350/TH350, 3.08 posi, 1st Gen Vintage Air, AAW wiring harness, 5-lug conversion, 1985 spindles and brakes. 1982 C10 SWB -- sold 1981 C10 Silverado LWB -- sold, but wish I still had it! 1969 C10 (not the current one) that I bought in the early 1980s. Paid $1200; sold for $1500 a few years later. Just a hint at the appreciation that was coming. Retired as a factory automation products salesman. Worked part-time over the years for an engine builder and a classic car repair shop. Member here for 24 years! This is the very first car/truck Internet forum I joined. I still used a dial-up modem back then! Last edited by MikeB; 05-02-2016 at 12:56 PM.

05-02-2016, 01:47 PM	#4
GMC Canuck Registered User Join Date: May 2012 Location: Ingersoll, Ontario Posts: 93	Re: solution to power brakes for engines with "lumpy" cams Maybe with a canister if the pump doesn't have the volume. Interested to hear how it works. Will the pump run all the time? How noisy is it?

05-02-2016, 02:02 PM	#5
AirSpeed Registered User Join Date: Jul 2007 Location: Fall River California Posts: 2,026	Re: solution to power brakes for engines with "lumpy" cams I bought a gm vacuum pump, tank and vacuum switch on Amazon, made an aluminum mount on my cnc and mounted it to the firewall, it really works great! Get about four stops before the vac pump turns on. Very happy with it! __________________ http://smg.photobucket.com/albums/v655/aaronhero/ Last edited by AirSpeed; 05-02-2016 at 02:05 PM. Reason: Pic

05-02-2016, 03:44 PM	#6
cleszkie Registered User Join Date: Feb 2003 Location: Santa Ana, CA Posts: 2,191	Re: solution to power brakes for engines with "lumpy" cams Does that have a pressure regulator built in? It should only cycle occasionally when the vacuum goes below a certain limit. It should also stop when the max vacuum is achieved. Otherwise, that pump will wear out from continuous use.

05-02-2016, 09:13 PM	#9
snipescastle2 Registered User Join Date: Mar 2009 Location: WARRENSBURG,MISSOURI,64093 Posts: 1,518	Re: solution to power brakes for engines with "lumpy" cams Out in the open it's kind of noisy, but I think once it's installed and plumbed up to the tank and booster shouldn't be too noticeable. Here is a couple of pics... Ben Attached Images __________________ "Persistence is the twin sister of Excellence.one is a matter of quality,the other, a matter of time" “Serious Black” my 1971 Short Bed Fleetside Sold to an outstanding man in Lees Summit,Mo. “Gone, but by no means,Forgotten”

05-02-2016, 09:17 PM	#10
snipescastle2 Registered User Join Date: Mar 2009 Location: WARRENSBURG,MISSOURI,64093 Posts: 1,518	Re: solution to power brakes for engines with "lumpy" cams Another... Attached Images __________________ "Persistence is the twin sister of Excellence.one is a matter of quality,the other, a matter of time" “Serious Black” my 1971 Short Bed Fleetside Sold to an outstanding man in Lees Summit,Mo. “Gone, but by no means,Forgotten”

05-02-2016, 09:45 PM	#11
CST10 Registered User Join Date: Sep 2013 Location: Gonzales, La Posts: 1,441	Re: solution to power brakes for engines with "lumpy" cams Sweet idea. Thanks for sharing. __________________ MyToys: Goldilocks the "Ol School Survivor" 1968 C10, SWB Stepside, 08/15 TOTM, 250 CI 6 cylinder, 3 on the tree, 3.73 rear, 3/5 static drop, 23,500 original miles. Samson the 1970 CST10, LWB, 462Ci, Turbo 350 tranny, 3.08 rear gear, PB, PS, A/C, AM/FM, 2/4 Drop. Brutus the 1998 Camaro Z28, 33,500 original miles, LS1, 519 RWHP/497 RWTQ. Member of the Louisiana Classic Truck Club, LCTC Member of the Louisiana C10 Club Member of the Baton Rouge Drifters Car Club

05-27-2016, 04:59 PM	#13
snipescastle2 Registered User Join Date: Mar 2009 Location: WARRENSBURG,MISSOURI,64093 Posts: 1,518	Re: solution to power brakes for engines with "lumpy" cams well, I have yet to try it out, but I did get an adjustable vacuum switch, cycles the pump on at 18 inches of vacuum, just haven't had time to test it out on the truck yet. I made a Vacuum accumulator out of a 5 pound oxygen bottle, couple that with all the braided hose I should have quite a good vacuum supply..... Ben __________________ "Persistence is the twin sister of Excellence.one is a matter of quality,the other, a matter of time" “Serious Black” my 1971 Short Bed Fleetside Sold to an outstanding man in Lees Summit,Mo. “Gone, but by no means,Forgotten”



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