252
Air System
Thermostat Disassembly
Refer to Figure 6-
47
.
1. Remove nut, then the lock washer, plain washer, nut, and O-rings. Discard the O-ring and keep
the other parts.
2. Remove and retain the four Phillips head screws and the cover.
3. Remove and discard the gasket.
4. Remove and retain the spacer.
5. Cut the uninsulated thermostat wire at Point “B”, and then remove and discard the thermostat
and terminal assembly.
6. Clean the remaining wire attached to the heater terminal.
7. Clean the thermostat “pocket” in the end cover.
Thermostat Assembly
Refer to Figure 6-
47
.
1. Cut the uninsulated wire lead of the new thermostat at Point “A”.
2. Install the thermostat in the “pocket” in the end cover and position the uninsulated leads next to
each other.
3. Use a soldering heat sink, clamp the uninsulated leads at Point “B” and solder the leads with
straight rosin core solder.
Do not use acid core, as corrosion can result.
Clean the excess solder
off the end cover.
4. Install the thermostat in the end cover.
5. Install the O-ring, washer, and nut. Tighten the nut to 20–30 in lb (2.3–3.4 N-m) torque. Install
the lock washer and nut finger tight to allow for reconnection of the electrical wire when rein
-
stalled on the coach.
6. Install the spacer over the thermostat.
7. Install the gasket and thermostat cover and secure the cover to the dryer end cover using screws
and lockwashers. Tighten the capscrews to 30–40 in lb (3.4–4.5 N-m) torque.
8. Test the thermostat.
a. At a temperature above 90° F (32° C), check the resistance between the thermostat terminal
and the end cover. The resistance should exceed 1,000 ohms. If not, check for a solder “path”
short.
b. Chill the entire end cover assembly to 40° F (4° C) or below and check the resistance again.
The resistance should be 2.0–4.0 ohms for the 12 volt, 60 watt end cover and 4.0–7.0 ohms
for the 24 volt, 120 watt end cover. The pressure protection valve should return sufficient air
in this system to provide for operation of those components.
9. With the spring brakes released, refill the air system to governor cut-out pressure.
10. With the engine running drain the primary air tank to 0 psi. Test for proper operation of the vis-
ible and audible low air warning devices in the primary circuit and shut off engine.
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...