MODERN BURNER UNIT (MBU)
UNIT MAINTENANCE PROCEDURES
VENT VALVE ASSEMBLY
THIS SECTION COVERS:
MBU shut-down, cool, and disconnected from power source
Tools and Special Tools
Shop Equipment Automotive Maintenance and Repair: Organizational Maintenance, Common No. 1
(WP 0038, Table 2, Item 2)
This procedure contains information and instructions to keep the MBU in good working order by
inspecting and replacing the entire vent valve assembly, consisting of a solenoid, level switch, overfill
check-valve, valve body, O-ring, and four mounting screws.
Two Person Lift
The MBU weighs approximately 58 pounds fully fueled (26.3 kg). Two persons must carry the
fully fueled MBU, lifting with legs, not back, to prevent injury.
Inspect the vent valve assembly for proper seating on the fuel tank. Check for damage to the valve head,
and solenoid. Check for loose power leads to the solenoid and float switch. Ensure vent orifice is not
Fire / Fuel Contamination
Before proceeding with this procedure, the MBU fuel tank must be drained completely as
described in work package 0011. Have rags on hand to clean up fuel spillage that may occur
to prevent contamination. Do not perform this procedure near an open flame to prevent fire.
To replace vent valve assembly (1) remove the reflective heat shield assembly as described in WP 0024.