Mack Granite Engine Brake Not Working

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Mack granite engine brake not working.

Engine brake is not working properly checking the solenoids for movement and replacing the o ring gaskets. To properly diagnose electrical problems with the brake an ammeter may be required. I got the oil changed and that didnt help. I changed the relay and checked the switch but they both are ok.

I did find one with a loose connection for the sol. Brake solenoid is fuse 2 in the engine compartment i have not found any fuses in the engine compartment. 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. Federal and canada motor vehicle safety standards mvss 106 brake hoses and 121 air brake systems.

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. The truck is a 2004 mack vision daycab. 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 2 3 50.

I looked at the schematic it says the fuse for the comp. Any change or addition to the system may cause the vehicle to no longer be in compliance with. I have not checked the power. 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 j tech engine brake is activated by the v mac system. 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 multimeter model i use to troubleshoot listed on the amazon affiliate link listed right here. I noticed about 2 months ago it would not work all the time only once and a while.