224
Air System
Retarder Brake Valve Adjustment Procedure
Equipment required to perform adjustments:
• Air Gauge
• Phillips Screw Driver
• 0.050 Allen Wrench
• Volt-Ohm Meter
switch Adjustments
Adjustments to the closing of the switches can be attained by inserting a 0.050 Allen screw, turning the
screw clockwise to decrease the amount of movement required to close the switch and counterclock
-
wise to increase the amount of movement required to close the switch. All adjustments of the switches
and readings of the volt-ohm meter are to be made with the treadle being depressed (downward stroke).
Never attempt to adjust the switches on the release of the treadle application (upward stroke).
calibration of micro switches on All treadle Actuated brake valves
(Except lever actuated model) See Figure 6-
29
. NOTE: Cannon connector pins are identified with num
-
bers and Packard connector pins are identified with letters.
1. Remove the two Phillips screws and remove the cover of the switch plate, exposing the switch
plate.
2. Unplug the power cable at the quick connect connector.
3. To adjust switch #1, connect the black lead of the volt- ohm meter to pin #3 or C of the connector
and the red lead to pin #1 or A of the connector. At this time there should be a maximum reading
on the meter (open circuit). Slowly start to depress the treadle. After approximately 1/4" move
-
ment at the end of the treadle, switch #1 should close and the volt-ohm meter will respond with a
reading of near 0 (closed circuit).
4. To check switch #2, leave the black lead of the volt-ohm meter connected to pin #3 or C of the
connector; connect the red lead to pin #4 or D. At this time, the meter will have a maximum read
-
ing (open circuit). Slowly depress the treadle until you can feel resistance to the movement being
applied. At the point of the end of the free travel of the treadle, approximately 1/2" movement
at the end of the treadle, switch #2 should close and the volt-ohm will respond with a reading
of near 0. If an adjustment to this switch is required, follow the instructions under the heading
“Switch Adjustments.”
5. To check switch #3, continue to have the black lead of the volt-ohm meter connected to pin #3
or C of the connector and connect the red lead to pin #2 or B. Install an air gauge in the primary
delivery circuit. With the treadle in the retracted position, the reading on the volt- ohm meter
will be maximum (open circuit). Slowly depress the treadle until the air delivery of the primary
circuit (shown on the air gauge) reaches 12 psi. At which time switch #3 should close and the
volt-ohm meter will respond with a reading of near 0. If an adjustment to this switch is required,
follow the instructions under the heading “Switch Adjustments.”
6. When all adjustments to the switches are complete, the Allen screws should be resealed using
any available sealant (such as paint or liquid gasket material).
Summary of Contents for LOW FLOOR
Page 18: ...Specifications 18...
Page 58: ...Preventive Maintenance 58...
Page 110: ...Engine 110...
Page 138: ...Transmission Driveline Rear Axle 138...
Page 182: ...Suspension 182...
Page 260: ...Air System 260...
Page 420: ...Electrical System 420 Deutsch DT Series Connectors...
Page 421: ...Electrical System 421...
Page 422: ...Electrical System 422 Deutsch HD 10 Series Connectors...
Page 423: ...Electrical System 423...
Page 424: ...Electrical System 424 Deutsch HD 30 Series Connectors...
Page 425: ...Electrical System 425...
Page 442: ...Heating Air Conditioning 442...
Page 492: ...Body and Interior 492 Figure 11 33 USSC Seat Assembly...
Page 493: ...Body and Interior 493 Figure 11 34 USSC Seat Suspension Assembly...
Page 495: ...Body and Interior 495 Figure 11 37 Seat Air Connections...