Mack Granite Engine Brake Not Working

I changed the relay and checked the switch but they both are ok.

Mack granite engine brake not working.

Brake solenoid is fuse 2 in the engine compartment i have not found any fuses in the engine compartment. I have not checked the power. The multimeter model i use to troubleshoot listed on the amazon affiliate link listed right here. Any change or addition to the system may cause the vehicle to no longer be in compliance with.

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. 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. Battery switches 2 3 50.

Engine brake is not working properly checking the solenoids for movement and replacing the o ring gaskets. About a month ago it quit working entirely. I got the oil changed and that didnt help. 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.

The reason for high cutting out and only low working is that the engine brake is not getting the required oil pressure to function properly. The model of this truck ctp713. The truck is a 2004 mack vision daycab. Federal and canada motor vehicle safety standards mvss 106 brake hoses and 121 air brake systems.

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. Battery switches 1 3 49 cd urea dosing system 22 ne additional ign. The j tech engine brake is activated by the v mac system. To properly diagnose electrical problems with the brake an ammeter may be required.