Mack Granite Engine Brake Not Working

I do have a fuse panel on top of the dash and one at the kick panel by the drivers door but it does not have a label.

Mack granite engine brake not working.

Ca engine interface mp 11 19 na o ignition battery sw spare connection 47 cb o dpf regeneration system 20 nb junction posts 48 cc engine heater 21 nc additional ign. To properly diagnose electrical problems with the brake an ammeter may be required. When the ignition switch is turned on the engine brake solenoids are supplied a constant 12 volt direct current with current flow increasing whenever the engine brake is activated. The truck is a 2004 mack vision daycab.

Battery switches 2 3 50. I changed the relay and checked the switch but they both are ok. I was talking to another driver today who drives a granite he says there is an oil pressure line that controls the engine brake and there is a small valve in that line that gets gummed up. I did find one with a loose connection for the sol.

I noticed about 2 months ago it would not work all the time only once and a while. Battery switches 1 3 49 cd urea dosing system 22 ne additional ign. Engine brake is not working properly checking the solenoids for movement and replacing the o ring gaskets. As manufactured by mack trucks inc the air brake system on mack chassis both incomplete and complete comply with the applicable requirements of u s.

I looked at the schematic it says the fuse for the comp. Federal and canada motor vehicle safety standards mvss 106 brake hoses and 121 air brake systems. About a month ago it quit working entirely. The model of this truck ctp713.

Brake solenoid is fuse 2 in the engine compartment i have not found any fuses in the engine compartment. I got the oil changed and that didnt help. Any change or addition to the system may cause the vehicle to no longer be in compliance with. I have not checked the power.