Usage:
E110B (8MF, 9HF);
E120 (1LF, 1MF);
E120B (7NF, 6JF)
Introduction
A swing dampening valve (bypass valve) is available for installation in the above model excavators. By installing the swing dampening valve, the operator should maintain more control over the bucket position with little or no overshoot when dumping.
This modification should only be performed on machines equipped with an automatic swing brake in the swing motor. This modification may increase swing drift when a machine, not equipped with a swing parking brake, is parked on a slope.
Do not perform any procedure outlined in this publication or order any parts until you have read and understood the information contained within.
Reference: Service Manual, Parts Manual, and Caterpillar Service Welding Guide, form SEBD0512.
Weld Parameters
Use LB-26 electrodes (AWS E7016)
Before using, dry the electrodes in an oven at 300°C (572°F) for a minimum of 30 minutes to remove moisture.
Parts Needed
Installation
1. Weld 1R9891 Support (2) to the inner surface of the swing frame left side plate. Make sure that the machined side of support (2) does not face the side plate.
2. Install 1R9168 Bypass Valve (1) onto support (2). Use 951595 O-rings that were supplied with valve (1).
3. Install 1R9914 Flange (3) onto bypass valve (1). Use two 951595 O-rings (10) between valve (1) and flange (3). Use eight 950658 Bolts (4) to fasten valve (1) to support (2).
4. Remove two plugs (A) and O-rings (B) from bypass valve (1). Plugs (A) and O-rings (B) will not be used again.
5. Install 951578 O-ring (9) and 951425 Connector (8) into each port of bypass valve (1) where plug (A) and O-ring (B) were removed.
6. Remove two gauge plugs (C) from the top of the swing motor. Plugs (C) will not be used again.
7. Install 951411 Connector (7) in place of each gauge plug (C).
8. Install 1R9930 Hose (5) and 1R9931 Hose (6) between connectors (7) and (8). Refer to the illustration of Step 2.
9. Start the engine, and set the speed at medium. Start and stop the swing operation several times to purge the hydraulic system of trapped air.
10. Check for leaks and fill the hydraulic tank to the correct level as specified in the Operation and Maintenance Manual.