KIT-WINDOW 3813129 - Caterpillar

Illustration 1 g00517132
Air ARC system
Illustration 2 g01205089
Hydraulic ARC system for the 784C, 785C, 785C HAA, 789C and 793D
The ARC will be activated when the following conditions exist:
The ON/OFF switch is in the ON position.
The throttle pedal is NOT depressed.
The parking brakes are in the RELEASED position.The ARC is not connected to the service brakes and the manual retarder. If the ARC is ENGAGED, air (oil) will flow from the valve of the ARC to a separate relay valve. The relay valve is located near the brake master cylinders.
Illustration 3 g01205114
Air activated ARC valve components located in the compartment in front of the cab
(1) Supply solenoid valve
(2) Control solenoid valve
(3) Auto retarder pressure switch
(4) Retarder pressure switch
Illustration 4 g01205118
Hydraulic activated ARC valve components located on the left frame rail close to the differential
(1) Supply solenoid valve
(2) Control solenoid valve
(5) Purge solenoid valve
(6) ARC accumulator In order to activate the ARC system, the Integrated Brake ECM sends electrical current to the supply solenoid (1). This will allow pilot pressure to shift the spool in the ARC valve which will result in high pressure air (oil) to flow to the control solenoid valve (2). The ECM will send a proportional current to the control solenoid valve in order to control the amount and duration of pressure that is applied to the brake cylinders.On machines with the hydraulic ARC system, the ECM will energize a front brake cooling diverter solenoid when the retarder is activated in order to cool the front brakes.On machines with the hydraulic ARC system, the steering bleed module will control the purge solenoid (5). When the key switch is turned to the OFF position, a timer in the steering bleed control will activate the purge solenoid in order to purge the ARC accumulator.The ARC is set at the factory in order to maintain a constant engine speed. An engine speed of 1900 rpm +/- 50 rpm should be maintained for the 3500 engines. An engine speed of 2230 rpm +/- 70 rpm should be maintained for the 3400 engines. The engine speed setting is programmable. The engine speed may oscillate beyond +/- 50 rpm of the target when the ARC initiates control of the retarder process. The engine speed should stabilize within a few seconds.The operator can activate the system by using the ARC ON/OFF switch in order for the ARC to operate properly. The operator should then select the correct gear for the grade, the load, and the ground conditions. The ARC is designed to permit the transmission to upshift into the selected gear of the shift lever. The ARC will apply the retarder after the transmission shifts into the selected gear and the engine speed exceeds 1850 - 1950 rpm for the