FRAME AS-LH 4750179 - Caterpillar

1. Move the ejector forward.
Make sure all of the pressure is released from the air system before disconnecting any air lines. Failure to release the pressure can cause the air to release rapidly when the lines are disconnected and could cause personal injury.
2. Disconnect four oil lines (3) and air line (2) from control valve (1).3. Remove three bolts (4) and control valve (1) from the transmission housing. The following steps are for installation of the retarder control valve.4. Put control valve (1) in position on the transmission housing, and install three bolts (4).5. Connect air line (2) to control valve (1).6. Connect four oil lines (3) to control valve (1).7. Check the oil level in the transmission.8. Move the ejector to the rear. Refer to the Topic "Lubricant Viscosities and Refill Capacities" in the "Operation and Maintenance Manual" for the proper filling procedure and the proper levels for the transmission.Disassemble Retarder Control Valve
Start By:a. remove retarder control valve
There is spring force against covers (1) and (2). To prevent possible personal injury, slowly remove the bolts that hold the covers, the spring force will be released.
1. Remove covers (1) and (2) from the retarder control valve. 2. Remove slug (4), spring (3), the stop, the spring and the valve spool from the retarder control valve. 3. Remove bolt (5), washer (6), plate (9) and diaphragm (7) from valve spool (8). 4. Remove plug (10), the spring and the plunger from the retarder control valve.Assemble Retarder Control Valve
1. Be sure the O-ring seal is in place on plug (2).2. Install plunger (1), spring (3) and plug (2) in the retarder control valve. 3. Install diaphragm (6) on valve spool (4).4. Install the bolt and the washer in plate (5).5. Install plate (5) on the valve spool, as shown, with the hole in the plate in alignment with the pin in valve spool (4). 6. Install valve spool (4) in the retarder control valve, as shown.7. Turn the lip of diaphragm (6) back so it will engage in the groove in the valve body. 8. Install spring (7), stop (8), spring (9) and slug (10), as shown, in the retarder control valve. 9. Install covers (12) and (11) on the retarder control valve.End By:a. install retarder control valve