BELLOWS AS 2071331 - Caterpillar

Functional Tests
The amber system fault indicator should not flash any time during these functional tests or during system operation. It only indicates when the system needs service. When it does flash, refer to the Service Manual for troubleshooting procedure.1. Turn on disconnect switch. The fire detection system and automatic discharge circuits will NOT function if the disconnect switch is turned off.2. Locate the fire suppression monitor shown in the Operators Manual. The monitor consists of a red light, an amber light, and a push button check switch. See Illustration 1.
Illustration 1. Monitor lights - 785 or 789 Trucks shown.3. Put the key start switch in the ON position. At this time the amber system fault indicator (LED) on the monitor panel should flash for only 6 to 8 seconds, and then turn off.4. Start engine and run at low idle. Steps 5 through 8 do NOT apply to off-highway trucks. If servicing an off-highway truck, go to Step 9.5. Put parking brake in PARK position.6. Push and hold the black CHECK switch on the monitor. Within one second after depressing the switch, the engine should shut down. The red FIRE indicator should flash and the horn should BEEP as long as the CHECK switch is held depressed.7. Restart engine and run at low idle.8. Disengage parking brake.9. Push and hold CHECK switch. The red FIRE indicator and horn should beep as long as the switch is depressed. The engine should not shut down.Visual Inspection
1. Inspect each temperature sensor. The number of temperature sensors and position of each sensor is identified in the Service Manual. The cylindrical portion of these sensors must not be covered with paint. PAINTED SENSORS CANNOT BE CLEANED; THEY MUST BE REPLACED TO GIVE SATISFACTORY PERFORMANCE. Remove any cardboard shipping tubes or tape.2. Remove and inspect each agent discharge nozzle for blockage. Again, the Service Manual shows the location of each nozzle on the machine. The 6T7677 Nozzles for Halon 2402 must contain 5N5561 Compound (silicone grease) packed inside the nozzle to keep paint and debris out of the tiny agent discharge holes. The two larger types of nozzles used with dry chemical agent should also be packed with 5N5561 Compound. See Illustration 2. Nozzles that do not have this compound in them should be inspected for blockage before installing any compound. Painted Halon 2402 nozzles without 5N5561 Compound must be replaced.
Illustration 2. The three types of discharge nozzles used.3. Inspect each nitrogen actuator, one in the cab and one outside the cab, to be sure the hairpin-shaped 7T8775 Lockpin is in place and retained by a 6T5 Flag Seal.4. Inspect the plunger in each actuator. Be sure it is free and not stuck in its bushing. With the lockpin in place per Step 3, carefully push/turn the plunger and check for slight movement. If the plunger is stuck, replace it.5. At the factory, a steel locking cable secures the lockpin in each nitrogen actuator with a corporate padlock to protect against vandalism when the