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Brake Booster question

Discussion in 'Non-Mopar Tech Support' started by Rickorino, Mar 9, 2015.

  1. Rickorino

    Rickorino Well-Known Member

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    I am about to replace the brake booster on my Ford F150 but am not sure it is bad. During cruising, everything is quiet. When the brakes are applied, I then hear a loud hissing in the cab. If I do a few panic type stops, the pedal gets slightly harder to press each time. After stopping the engine and pumping the brakes, there is little power assist available. I was told by an "expert", that it may be some gasket or seal associated with the booster because it does not hiss all the time. I would appreciate any suggestions.
     
  2. valiant67

    valiant67 Rich Corinthian Leather
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    The booster is a closed unit, other than the vacuum source, there is no external seal or gasket to leak vacuum. There is a check valve on the line into the booster than can go bad, but what you are describing sure sounds like a failed booster.
     
  3. Rickorino

    Rickorino Well-Known Member

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    Thanks for replying. I will order a new one. The check valve and the grommet are good.
     
  4. valiant67

    valiant67 Rich Corinthian Leather
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    One more thing to look at - sometimes the rear seal on he master cylinder will go bad and the vacuum booster will suck brake fluid inside. That will deteriorate the booster faster, so look for any evidence of that and change the master cylinder if it's an issue.
     
  5. Rickorino

    Rickorino Well-Known Member

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    I checked for a leaking master cylinder and all is dry and clean. Replaced the booster today and all is well. Thanks for responding.
     

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