Thread: Brake booster
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Old 13th August 2016, 23:08
Mike Mike is offline
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Originally Posted by phil.coyle View Post
Have you checked the one way valve in the Hose to the servo.
Some are obvious in the Hose, and others are at the point of entry into the Servo.
It is unlikely to be the non return valve in the vacuum hose.
If this is faulty you will lose vacuum, which is not your experience - quite the opposite!

The cause will be one of two issues:

The inlet valve on the servo not quite seating, allowing atmospheric pressure to exert a force on the servo's diaphragms, or

The mater cylinder is not returning fully, so retaining hydraulic pressure in the system.
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