BRAKE RELEASE AR 2151522 - Caterpillar

2. Remove the three bolts and guard that protect the hose connections.3. Put identification marks on two hose assemblies (4) for installation purposes.4. Disconnect two hose assemblies (4), tube assembly (2), and remove bracket (3).5. Remove two bolts (1). Remove the quick drop valve and the O-ring seal from the lift cylinder. The following steps are for installation of the quick drop valve.6. Install the O-ring seal onto the quick drop valve. Put the quick drop valve in position on the lift cylinder and start bolts (1), but do not tighten until tube assembly (2) has been connected.7. Put bracket (3) in position, and connect tube assembly (2). Connect hose assemblies (4).8. Tighten bolts (1), and install the guard. Frame Mount Quick Drop Valve
To prevent personal injury, release the pressure from the hydraulic system before any lines are removed or disconnected.
1. Remove guard (1) from over the quick drop valve. 2. Disconnect hoses (2) from the valve. 3. Swing the radiator guard open and remove lines (4) and bolts (3). 4. Remove bolts (3) and remove quick drop valve (5). Upon installation of the quick drop valve, reverse the procedures of Steps 1 through 3.Disassemble And Assemble Bulldozer Quick Drop Valves
Two different types of quick drop valves are used on the D6H Series II, depending on on the serial number of the unit. Both valves will be presented in this procedure. The first unit is located on top of each of the lift cylinders. Its serial numbers are 3ZF4000-5499 and 3YG4000-5499. The other unit is located above the radiator in the exact canter of the machine. Its serial numbers are 4RC5500-UP and 6FC5500-UP. Cylinder Mount Quick Drop ValveStart By:a. remove quick drop valves 1. Remove two bolts (1).2. Loosen three bolts (4) evenly to release the spring pressure, and remove manifold (2) from valve body (3).3. Remove the four O-ring seals from manifold (2). 4. Remove spring (8), washer (7), plunger (6), and stem (5) from valve body (3).5. If necessary, remove plug (10) from the stem and orifice (9) from the valve body. The following steps are for assembly of the bulldozer quick drop valves.6. Put clean oil on the parts during assembly.7. Install plug (10) and orifice (9) if they were removed.8. Install stem (5), plunger (6), washer (7), and spring (8) into valve body (3).9. Install the four O-ring seals into manifold (2). Put manifold (2) in position on valve body (3). Make sure spring (8) is aligned with the hole in the manifold, and install bolts (1) and (2).End By:a. install bulldozer quick drop valves Frame Mount Quick Drop Valve Certain portions of this valve are nonservicable. It is necessary however to reference them in order to gain access to the parts that are serviceable.1. Remove four bolts (1) and remove cover (2).2. Remove O-ring seal (4).3. Remove plug and O-ring seal (3).4. Remove stem and piston (5).5. Remove spring (7).6. Turn valve around and remove four bolts (10), cover (12) and O-ring (11).7.