Holiday imperial 2001, Руководство пользователя

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Chassis Information
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I M P E R I A L
1 0 • 2 5 2
65 psi (pounds per square inch).
A simple mechanical explanation of what occurs when a brake application is
made is as follows: The air system supplies air to the foot brake, this is called a
treadle valve. Pushing down on the treadle valve supplies an air charge signal to
a brake chamber. This sealed chamber consists of a spring and air bladder. The
air charge signal pushes on the bladder which extends a threaded rod connected
to the automatic slack adjuster. The slack adjuster rotates the S-cam expanding
the shoes against the drum. Air disc brakes follow much the same principal,
with the exception of the S-cams.
The park and emergency brake systems are combined and apply to the rear
drive axle only. These are called spring brakes. When the park brake is applied
air is released from the rear brake chambers allowing the large spring in each
rear brake chamber to manually push against the automatic slack adjuster. This
rotates the S-cam applying the brake shoes against the drum. The air system
charged above 35 psi is approximately the point at which the park brake will
remain released. Pushing down on the park brake handle charges the rear brake
chambers with air pressure, overriding the emergency brake springs and releas-
ing the brakes. In the event of air loss while the vehicle is under operation, the
park brake will automatically apply, (this occurs at approximately 30 psi) acting
as an automatic emergency brake system.
When preparing to depart, allow the air system to achieve full air pressure.
This is indicated by the air gauge needles. Listen for the air dryer to purge, indi-
cating full air pressure has been obtained and air dryer is functioning. Look and
listen for any abnormalities. Abnormal air pressure readings by either needle of
the air gauge should alert the operator. Have the air system checked to avoid an
untimely failure.
Should a failure occur in the air system, preventing the air pressure from
building, it may become necessary to “cage” the spring brakes. This is an emer-
gency procedure only. Caging the rear air brake chambers manually overrides
the spring brakes and allows the vehicle to move. This procedure does not affect
normal service braking. The brake disabling procedure is located in Section 2.
NOTE When park brake is released. Park illumination lamp will
remain lit until air system pressure is above 65 psi.
The motorhome is equipped with automatic slack adjusters. As brake
linings wear the slack adjusters will automatically ratchet on the return
stroke as needed. This ratchet action will keep the brake linings at prop-
er adjustment. Brake adjustment should not be necessary. Indications of
a vehicle needing a possible brake adjustment may be noticed by the
park brake not holding on a hill or gradual loss of braking power.
BRAKE PARK &
EMERGENCY
SYSTEMS
BRAKE
ADJUSTMENT/
SLACK ADJUSTER