Brake Servo - Winnebago 1987-1989 LeSharo Service Manual

BRAKE SERVO
Checking for Loss of Vacuum Pressure
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The check for loss of vacuum pressure in the brake
servo unit must be carried out with the hydraulic
circuit functioning normally.
• Connect a vacuum gauge to the line between the
brake servo and vacuum source (inlet manifold)
using a "T" piece union and as short a length of
flexible pipe as possible.
• Run the engine at idling speed for 1 minute.
• Clamp the pipe between the "T" piece union and
vacuum source using clamp Mot. 453-01.
• Switch off the engine.
• If the vacuum drops 33 m/bar (1" Hg) within
15
seconds,a leak is present which may be in either:
- the check valve (change it)
or in the pushrod diaphragm (if in the latter,
change the complete servo)
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Tool Mot,453-01