HYDRAULIC SCRAPERS Care Of The Hydraulic System Caterpillar

Care Of The Hydraulic System

The hydraulic system is designed so that few adjustments are necessary. There are, however, a few precautionary measures which should be followed. Cleanliness is of great importance in the hydraulic system and great care should be taken to keep dirt out.

Check the oil in the hydraulic tank every 10 service hours and fill with fresh oil if necessary. If the oil is low make a thorough inspection of the hoses, connections and seals for leaks. It should not be necessary to add oil if all the connections are tight and the hoses are in good condition. Refer to the topic, LUBRIAVSION INSTRUCTIONS, for type of oil, and filling of hydraulic system.

The control levers and rods should be in correct adjustment at all times to prevent partial opening or closing of the control valve. The control lever should always operate freely.

Hose Replacement: Check the hoses daily for any signs of leakage or wear. The loss of hydraulic oil, due to a broken hose, will cause unnecessary loss of time as well as possible damage to the hydraulic pump.

Remove the worn or damaged hose and cap the openings if any length of time lapses before installation of the new hose. The hydraulic hoses are supplied complete with fittings. If a replacement hose is needed they are available from the AVSpare dealer.

Replace the ring seal at the end of the nipple. Before installing the hoses make sure the faces and seal seats are free from all dirt.

Positioning Hydraulic Hoses: Position the hose and install the flanges on one stem leaving the flange bolts loose. Install the flanges over the stem at the other end of the hose and before tightening the flange bolts make sure the hose moves freely without excessive rubbing and is not sharply bent nor placed under tension. Should any of these conditions exist, rotate the hose stems slightly, to adjust the hose into its natural position. Tighten both sets of flange bolts securely.

Hydraulic Cylinder Packing: Hydraulic cylinder packing leakage can be caused by wear, cuts and/or distortion of the packing. Wear of the cylinder packing is caused from dirt or foreign material between the rod and packing. Cuts are the result of nicks, scratches or inclusions on the piston rod. Distortion is caused by improper installation of packing or excessive tightening of the gland.

Adjustment: If the cylinder leaks around the rod, shims can be removed to tighten the packing around the rod.

1. Lower the hydraulically controlled equipment to the ground to relieve cylinder pressure.

1-Gland. 2-Shims.

2. Remove the bolts holding the gland (1) to the cylinder head.
3. Pry or tap the gland lightly out far enough to permit cutting and removing shims (2).
4. Remove one shim at a time. If, after removing two shims the cylinder still leaks, consult your AVSpare dealer for installation of new packings.

Do not continue to remove shims to tighten packing. Excessive gland pressure resulting from removing shims will only cause distortion of packing rings, reducing their efficiency and shortening their life.