Vaccum Boosters

Anonymous-0 · Feb 26, 2013

How can you test it on the vehicle? It is on a 70's GMC if it makes adifference. Thanks in advance. J.

greygoat · Feb 26, 2013

Do you mean a vacuum chamber, such as on power
brakes..it would have a port and i"d use a hand
vacuum pump..such as I also use to bleed brakes,
or test a vacuum "pull off" on old carbs.
If it"s a vacuum pump type..how about a vacuum gauge..hosed to the suction side ?

John B. · Feb 26, 2013

With the engine off. If you pull the vacuum hose off the booster you should hear a rush of air get sucked into it.

Rex in Australia · Feb 26, 2013

Turn the engine off. Pump the brakes slowly. the pedal should get harder to push and travel less as the vaccuum is used up. Hold the brake down, start the engine. As the vaccuum builds, you should feel the pedal go down as the vaccuum pulls it on. That's it! If that doesn't happen, it's not working.

Rx

mtn.man · Feb 26, 2013

Rex is right this is the best way to check a brake booster.

504 · Feb 26, 2013

What Rex said.

ShadetreeRet · Feb 26, 2013

And, if you find it is not working properly, it doesn't necessarily mean the entire unit is bad. Many or most vacuum boosters have a check valve where the vacuum line attaches that can fail.

Vaccum Boosters

Anonymous-0

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greygoat

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John B.

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Rex in Australia

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mtn.man

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504

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ShadetreeRet

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