BOLT-HEX HEAD 4757273 - Caterpillar

Before any air lines are disconnected make sure the air pressure is zero.
1. Loosen two plugs (1) to release the air from the air tanks. 2. Remove plate assembly (2) from the machine.3. Put identification on the tube assemblies and air hoses before they are disconnected from the pressure protection valve for correct installation. 4. Disconnect tube assemblies (3), (4) and (7) from the pressure protection valve.5. Disconnect hoses (8) and (9) from the valve.6. Remove two bolts (5) that hold pressure protection valve (6) to the bracket. Remove the valve.Install Pressure Protection Valve
1. Put pressure protection valve (1) in position on the bracket as shown and install the two bolts that hold it.2. Connect the three tube assemblies and two hoses to the valve. Make sure the hoses and tube assemblies are in the corrct positions. 3. Install plate assembly (2) over the pressure protection valve.