Does not creat enough vaacum for my power brake to work

SHRIMP 128

MEMBER
1970 FORD MUSTANG
V8
RWD
AUTOMATIC
50 MILES

Brought to a auto shop they said I only have 8-11" of vaacum need more they recomened me to change the distributor set up I have a msd coil distributor and inigtion set up the motor is a high performance motor brand new 351 winsor 4 brael 750 holly double pumper carburator I think their is a high performance cam inside I bought the vaacum pump still not working right so I bought another electri vaacum pump for it did not put in yet need help not sure that will solve the problem someone said the motor need to be in perfect runing sharpe before I get the proper vaacum for my power brakes to work can you tell me what should I do I already spend $1000.00 on it for them to tell me to change my msd set up. Should I listen to them or not

4 Replies

JACOBANDNICKOLAS

MECHANIC
109,749 POSTS

For the vacuum to be an issue, either you have a good size leak at some point, or you have timing or compression issue. Have any of those items been checked?

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Wednesday, January 21st, 2015 AT 10:58 AM

SHRIMP 128

MEMBER
2 POSTS

Well, I paid $1000 already they change the spark plug and check whatever need to be check they said that they had spend over 6 hours on my car they recomended that I need to change my distrubtor to get the vaacum for my power brakes I want to know should I listen to them to change my msd set up or get another opinion

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Wednesday, January 21st, 2015 AT 12:30 PM

SHRIMP 128

MEMBER
2 POSTS

Well already paid $1000 for them to change the spark plug and whatever they did to check they said they had spended 6 hours on my car they want me to change the distrubitor should I listen to them I have a high performance motor with the MSD set up band new motor with a high performance cam what do you think I should do?

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Wednesday, January 21st, 2015 AT 1:25 PM

CJ MEDEVAC

MECHANIC
11,004 POSTS

DIFFERENT GUY

I'M THINKING THAT YOU ARE BEING TOOK FOR A RIDE, BUT NOT IN YOUR 'STANG!

I'M NOT MUCH ON HOW THE CAM IS GONNA AFFECT YOUR VACUUM, BUT I'D SPEND $25-$35 ON A "DASH MOUNT" (ON/ UNDER/ WINDSHIELD STRUT) VACUUM GAUGE FROM THE AUTO PARTS STORE.

AFTER YOU USE IT FOR A TEST, YOU CAN STICK IT IN YOUR TOOLBOX, OR MOUNT IT IN THE CAR

IT CAN BE USED NOT ONLY FOR A TEST, BUT YOU CAN DIAGNOSE INTERNAL ENGINE PROBLEMS (BY THE WAY IT ACTS), YOU CAN ALSO "TWEAK" YOUR DRIVING HABITS TO GAIN MORE MPGs

I WOULD OBTAIN THE GAUGE AND TEST THE VACUUM MYSELF

MYSELF, AS A JEEP CJ KINDA GUY, AND HAVE DEALT MAINLY WITH CARBS SINCE I WAS A KID, BACK IN '70s

I CAN SEE CARB ADJUSTMENTS AND TIMING ADJUSTMENTS IMPROVING VACUUM, JUST IN GETTING EVERYTHING WORKING EFFICIENTLY

I JUST DON'T "IGNITION" IS GONNA MAKE THE PISTONS SUCK IN MORE AIR, CHANGING THE CAM MIGHT! (OR MAY NOT) EXPLOSIONS IN THE CYLINDERS ARE EXPLOSIONS, I EVEN THINK THE STOCK IGNITION WOULD PRETTY MUCH BE THE SAME EFFECT

ON A "NORMAL" RIG, 20 Hg OR INCHES OF VACUUM IS NORMAL

AS THE 1st FELLER MENTIONED, LOOK FOR VACUUM LEAKS!

THEY ARE USUALLY THE SOURCE THAT DROPS YOUR VACUUM, LOOSE OR BROKEN HOSES (YOU SHOULD ONLY HAVE A FEW ON A '70), LOOSE CARB, POORLY INSTALLED INTAKE MANIFOLD, ETC!

I BELIEVE I'D LOOK FOR ANOTHER GARAGE TO WORK ON YOUR CAR, IT'S MUCH MORE SIMPLE THAN THE NEWER ONES AND SHOULD NOT COST A FORTUNE (WITHOUT A BREAKDOWN OF WHAT WAS DONE AND PARTS) ALL I CAN BASE THIS ON IS WHAT YOU HAVE SAID

I CAN MAKE RECOMMENDATIONS ON LOOKING FOR A MORE SUITABLE SHOP, JUST ASK ME!

HERE'S SOME MORE VACUUM RELATED STUFF I'VE ANSWERED IN THIS LINK

http://www.2carpros.com/questions/2010-all-other-cars-how-to-change-gears-for-fuel

PAY SPECIAL ATTENTION TO MY PICS OF MY TWO REALLY PERTTY JEEPS WITH IN DASH VACUUM GAUGES!

YOUR TURN, J&N (1ST GUY) AND I WILL RESPOND AS LONG AS YOU DO!

THE MEDIC

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