TUBE AS 2279632 - Caterpillar

Always wipe the inside of the coupler and the outside of the connector tip clean with a clean, lint-free cloth prior to completing the connection. Failure to do so will reduce the life of the quick coupler and contaminate the oil in the implement circuit.
* Low Pressure Return Circuit Coupler A low pressure return circuit is available by removing threaded plug (3) and installing coupler (4). The low pressure return circuit will reduce back pressure in the remote hydraulic return line which will result in more efficient hydraulic motor operation. The return circuit can also be used in applications where low return oil pressure is desired to improve implement operation, such as orbit motor case drain lines.The following connectors and couplers are available from your Caterpillar dealer:
Fluid escaping under pressure, even a pinhole-sized leak, can penetrate body tissue, causing serious injury and possible death.Always use a board or cardboard when checking for a leak. If fluid is injected into your skin, it must be treated by a doctor familiar with this type of injury immediately.
Always wipe the inside of the coupler and the outside of the connector tip clean with a clean, lint-free cloth prior to completing the connection. Failure to do so will reduce the life of the quick coupler and contaminate the oil in the implement circuit.
Application Guidelines
Operating Single-Acting Cylinders
Single-acting cylinder (1) will typically only have one hose to connect. Connect the hose to a left side (EXTEND) coupler on the circuit desired.To extend the cylinder, pull the control lever on the circuit selected back to the EXTEND position. To retract the cylinder, push the lever fully forward to the FLOAT position. The lever will not automatically return to the HOLD position when the cylinder reaches the end of its stroke. Always use the FLOAT position to retract a single-acting cylinder. The RETRACT position is for double-acting cylinders only.Operating Double-Acting Cylinders
Connect the "extend" or "up" hose from double-acting cylinder (2) to a left side (EXTEND) coupler on the circuit desired and the return hose to the right side (RETRACT) coupler of the same circuit.To extend the cylinder, pull the corresponding implement control lever to the EXTEND position. To retract the cylinder, push the lever to the RETRACT position.Further forward movement of the lever will select FLOAT, which will allow the cylinder to extend or retract freely. This feature is useful when carrying out work with equipment such as scraper blades and loaders.Bleeding Remote Cylinders
When connecting to a cylinder with trapped air, such as a new cylinder, one that has been out of service or one that has had its hoses disconnected, it will be necessary to bleed the cylinder to remove the air.With the hoses