Mack Granite Engine Brake Not Working

Any change or addition to the system may cause the vehicle to no longer be in compliance with.

Mack granite engine brake not working.

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. 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. I looked at the schematic it says the fuse for the comp. I changed the relay and checked the switch but they both are ok. The multimeter model i use to troubleshoot listed on the amazon affiliate link listed right here.

I got the oil changed and that didnt help. 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. I noticed about 2 months ago it would not work all the time only once and a while. The model of this truck ctp713.

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. Brake solenoid is fuse 2 in the engine compartment i have not found any fuses in the engine compartment. 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. Battery switches 1 3 49 cd urea dosing system 22 ne additional ign.

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. Battery switches 2 3 50. I have not checked the power. I did find one with a loose connection for the sol.