General • Inspections

2010 Mack Natural Gas MRU,LEU: BEFORE PERFORMING MAINTENANCE ON THE LNG OR CNG TANKS OR FUEL SYSTEM

Use this checklist before doing any maintenance on your Mack truck. Performing regular maintenance on your equipment has been proven to reduce repair costs for trucks and to avoid unnecessary damages.

MaintainX

12/28/2022

2010 Mack Natural Gas MRU,LEU: BEFORE PERFORMING MAINTENANCE ON THE LNG OR CNG TANKS OR FUEL SYSTEM

Note: Separate methane detector/alarm systems should be installed in facilities that frequently house LNG/CNG vehicles. In addition, hand-held methane detector/ alarm devices should be used when working on LNG/ CNG vehicles with a non-functioning or disconnected methane detector/alarm system and where no auxiliary methane detector/alarm system is installed.

Removing Pressure Before Working on the Engine Fuel System

Before servicing the LNG/CNG engine fuel system, remove pressure from the fuel lines by turning the valves on each tank to the OFF position. This will stop more fuel from entering the lines to the engine. Allow the engine to run until it "dies."

Removing Pressure Before Working on the Tanks

If the fuel lines between the tanks or the tanks themselves must be worked on, the system must be totally "bled" of fuel, including the tanks. With a minimum amount of fuel in the tanks, open the manual vent valves on the tanks until the tank pressure gauges read zero.

Note: If possible, try to service the tanks after the vehicle has used most of its on-board fuel.

Moving a Vehicle Using Auxiliary Fuel

When LNG tanks are not fueled or have been removed, the vehicle may be moved by connecting an auxiliary CNG (compressed natural gas) tank to the connection located on the left side frame rail behind the front inside of the fuel tank on the driver side.

Turn the three-way valve to AUX to operate the vehicle from an auxiliary tank.

Turn the valve to ON to operate from the main tank(s) and, be sure to turn the valve to OFF when parking the vehicle.

Three-way Fuel Valve

Source: MaintainX (Community Member)