RING-PISTON 4P8958 - Caterpillar

Keep The Machine Clean
Excavators working in forests, road construction, and housing developments are more apt to accumulate debris than those working in open areas. Nothing burns faster than oil soaked pine needles, leaves, and twigs. See Illustration 1. Users of excavators in these environments must spend more time on cleanliness, and even minor leaks or electrical malfunctions should be fixed as soon as possible.
Preventing Hydraulic Hose Inteference
High pressure or low pressure hoses can rub sheet metal, firewalls, frame members and posts, as well as other hoses and tubes. Why?
Illustration 1. Trash and rags create a potential hazard.... If the clamps are missing, loose or improperly positioned, this can allow a hose to move and wear everytime it is pressurized.... Field-fabricated hoses with stems or elbows installed at wrong angle.... Sometimes hoses are not installed or routed correctly after field repairs.Hose interference can sometimes be corrected by loosening the flanges or fittings and turning the hose slightly, or repositioning the clamps. When new hoses are installed, be sure they are routed the same way as the old hoses. Start the excavator and operate it in all positions and cycles to see if interference occurs, particularly during pressure surges. See Illustration 2.
Illustration 2. A hose rubbing the clamshell attachment.
Illustration 3. A missing clamp may allow vibration to wear a hole in these tubes.
Illustration 4. Damage in these areas can force the hydraulic tank and hydraulic lines out of alignment.Some excavators are equipped with other manufacturers' auxiliary equipment, such as hydraulic hammers, grapples, mowers, and logging attachments. The additional hydraulic lines must be properly routed and clamped to prevent interference. You should make the user aware of good installation practices where you do not perform the installation.
Keep Hydraulic Tubes Tight And In Alignment
Loose tube clamps causes wear and eventually leaks.
A few tubes were observed where the flange had been welded or brazed to the tube because the joint had loosened and leaked. If a joint leaks, find and correct the cause to prevent a subsequent failure.
All tubes flex a small amount due to pressure fluctuations and they are designed to withstand this without being overstressed. This is accomplished by swedging the flange around the end of the tube. However, if the joint is prestressed too much because the tube is not aligned when installed on the machine, the additional stresses from pressure fluctuations can cause the joint to fail. Thus, when a tube is installed, be sure both ends are correctly aligned and tightened before any clamps are tightened.
Correct alignment of the flanges may be difficult if the tube has been bent or if the components connected to the tube have been forced out of alignment. Remember to install all clamps. See Illustration 3.
Component Misalignment
Excavators working around trees or large rocks sometimes have damage to the outside of the house, particularly the right rear corner. Illustration 4 shows typical minor damage. Sometimes the blow is severe enough to bend the outer channel and the hydraulic tank outrigger of the upper frame.