Power Brakes Vac Pump

[Bruzilla]

My engine vacuum is low to a point where the power brakes aren't working very well. If you watched Graveyard Carz a few weeks ago, and saw Worman talking about low vacuum, that's the problem I am having.

I was wondering if connecting a 12V Dorman pump that the Ford F-250 diesel trucks use to operate their brakes would work? Any suggestions?

 

[dieseldazzle]

It will probably work but what can do you have that is causing such a low vacuum situation in your 440? I thought it was mild?

 

[Bruzilla]

It will probably work but what can do you have that is causing such a low vacuum situation in your 440? I thought it was mild?

You would think coming from a 73 Town & Country it would be. When I bought it, the guy I got it from, who had inherited the car from his neighbor, told me the guy used to race the car at Jax Raceways, which I thought was BS until I saw the SW gauges inside. The engine definitely has been warmed over and lopes quite a bit.

 

[Xp29h]

I had a vacuum pump in my car when I bought it. The guy said it was due to a "larger" cam. Well he was right it had low vacuum and a pump but still didn't have brakes. The pump showed 25 inches mercury right where it should be but still no brakes.. Master cylinder was installed wrong with the pushrod. So, no matter what I had it wasn't working.. Double check everything before you spend money on a pump. Make sure the MC is good, the booster diaphragm is good etc. then add the pump iff needed!

Good Luck

 

[dieseldazzle]

I'd put a vacuum gauge on it. Also Napa autozone I've had both power boosters be junk

 

[Bruzilla]

Its a new MV and booster from O-Reillys, and I've had a gauge on it, and I'm nowhere's close to 20. More like ten.

 

[PurpleBeeper]

Its a new MV and booster from O-Reillys, and I've had a gauge on it, and I'm nowhere's close to 20. More like ten.

Well, my car was at 6" vacuum & a vacuum reservoir canister wasn't much help. I tuned the carburetor(s) and now have 12" vacuum and the reservoir isn't even needed. Just a thought...

 

[black64]

Good way to check Booster is have your foot on the brake pedal when you start the engine if the pedal drops some it is working. 10 inches of vacuum is a problem you need 13 inches minimum and then you would need a reservoir. I bought one from master power brakes it was 250 dollars and that was in 2004. Vacuum pumps are noisy and need to be mounted close to the booster.

 

[Bruzilla]

I wondered about the noise, but when you have headers, exhaust leaks, and Flowmasters... that would have to be one Hell of a loud pump to be heard.

 

[black64]

I wondered about the noise, but when you have headers, exhaust leaks, and Flowmasters... that would have to be one Hell of a loud pump to be heard.

Just don't mount it inside the car ask me how I know

 

[PaveFE]

I use a CVR VP555 vacuum pump mounted under the battery tray. You really have to look to know it's there.

 

[rrTor-Red]

Its a new MV and booster from O-Reillys, and I've had a gauge on it, and I'm nowhere's close to 20. More like ten.

Parts from O'Reilly's might be the issue right off the bat. Got a reman caliper from them. First one, it looked like hammered dog crap. I didn't like it so I sent it back, without taking it out of the store, and told them to get another one. Second one came a couple of hours later and some a-hole decided to paint this one gold

Anyway, my car does have slightly lower vacuum at idle. It has 11 psi then goes up to 15

 

[YY1]

The vac on my D150 was terrible until I tuned it with a gauge.

Mild 440 and manual trans.

Had 6" and would barely operate the booster.

Now it has 12" and the brakes are fine.

Runs a lot better, too.

 

[Yatzee]

My engine vacuum is low to a point where the power brakes aren't working very well. If you watched Graveyard Carz a few weeks ago, and saw Worman talking about low vacuum, that's the problem I am having.

I was wondering if connecting a 12V Dorman pump that the Ford F-250 diesel trucks use to operate their brakes would work? Any suggestions?

Bottom line is ( and don't let anyone tell you otherwise ) you need a minimum of 18" of vacuum to have SAFELY operating power brakes with no less than a 9" booster. Doesn't matter if you went to a double 8 or 7, it's the surface area of the diaphram that counts not the number of diaphrams when it comes to vacuum pressure. The more diaphrams, the greater volume of vacuum you'll need to operate the diaphrams. Been there done that! The Ford vacuum pump will work just fine and is not that noisey - it's really a quality part. Keep in mind, Ford used check valves in the feed line and in some cases an "out of sight" vacuum reservoir. Pump will pull 25 amps.

 

[496BEE]

I wondered about the noise, but when you have headers, exhaust leaks, and Flowmasters... that would have to be one Hell of a loud pump to be heard.

I actually have my pump and tank mounted behind the driver's head light and still you can hear it clearly. It's actually surprisingly loud

 

[Bruzilla]

I got the pump in today, and will install it tomorrow.

 

[Bruzilla]

Okay... I get today's Dumbass award. I checked the vacuum lines, sprayed starter fluid around the intake, carb, rear port, etc., and nothing. Then I went to install the line from the pump and went to disconnect the line from the carb to the brake booster and saw that one of the ports on the booster was uncapped!. It was on the bottom and I didn't see it when I put the booster in.

I capped the port and voila... power brakes.

 

[dieseldazzle]

.....tried to tell ya man... a mild motor likes yours sounds should have plenty of vacuum.

Bet your carb issues disappear now too lol

 

[rrTor-Red]

Glad our issue was resolved. We all make mistakes

 

[Malicious]

yeah I mounted my pump under the battery, vac tank is in the drivers wheel well up near the bumper. works great now but its running too much. I think I need to check for leaks. The advantage of the pump is I can listen for leaks with the engine off!

As for noise, you can easily hear it with the engine off, you have to listen for it in the car when the engine is on, but generally its overridden by my noisey *** exhaust!