Usage:
IT12F (1KF),
IT14F (4EL) Integrated Toolcarriers
Reference: Service Manual Module, SENR5961, Testing and Adjusting, IT12F Integrated Toolcarrier, Hydraulic System; Page 30; "Tilt Circuit Head End Relief Valve". This module is found in Service Manual, SENR5950.
Reference: Service Manual Module, SENR6609, Testing and Adjusting, IT14F Integrated Toolcarrier, Hydraulic System; Page 30; "Tilt Circuit Head End Relief Valve". This module is found in Service Manual, SENR6600.
Reference: Service Manual Module, SENR5961, System Operation, IT12F Integrated Toolcarrier, Hydraulic System; Page 14; "Makeup and Relief Valves". This module is found in Service Manual, SENR5950.
Reference: Service Manual Module, SENR6609, System Operation, IT14F Integrated Toolcarrier, Hydraulic System; Page 14; "Tilt Circuit Makeup and Relief Valves". This module is found in Service Manual, SENR6600.
The 121-0715 Control Valve is a regenerative (regen) valve that is available to replace the tilt section of the main control valve. This regen valve combines head end oil and rod end oil for increased flow to the tilt cylinders for the dump position. The increased flow of hydraulic oil to the cylinders works to prevent voiding due to cylinder collapse when external load forces exceed the pump flow.
Voiding is most prevalent at back-drag operations whereby the bucket "flops" up due to tilt cylinder voiding. Although the 121-0715 Control Valve will improve tilt cylinder voiding, the operator may not be able to hold the bucket and back-drag at low idle. Increasing low idle by 100 rpm will improve bucket holding during back-drag operations.
Illustration 1.
Main Control Valve (3 valve block pictured).
The 121-0715 Control Valve is adaptable to IT12F (1KF820-Up) and IT14F (4EL83-Up) Machines and is available through normal parts ordering channels. Because the 121-0715 Control Valve can be used on both the IT12F and IT14F Machines, the relief valves for the head end (3) and the rod end (4) circuits must be set for specific relief pressures. See Illustration 1.
The settings for the relief valves are provided in Table 1.
