GASKET KIT 5P4860 - Caterpillar

At operating temperature, the hydraulic oil tank is hot and under pressure. Hot oil can cause burns. To prevent possible personal injury, release the pressure in the implement hydraulic circuits (boom, stick and bucket) before any hydraulic lines or components are disconnected or removed.
1. Release the pressure in the hydraulic system as follows: a. Fully retract the rod in the stick cylinder.b. Adjust the position of the bucket so it will be flat on the ground when the boom is lowered.c. Lower the boom until the bucket is flat on the ground.d. Shut off the engine, and put the hydraulic activation control lever in the "Lock" position.e. Move the control levers for the boom, bucket, stick and swing through their full travel strokes. This will relieve any pressure that may be present in the pilot system.f. Slowly loosen the air breather cap on the hydraulic oil tank to release the pressure.g. Tighten the air breather cap on the hydraulic oil tank.h. The pressure in the hydraulic system has now been released. Lines and components can now be removed. 2. Disconnect hose assembly (3) from the bottom of the bypass check valve. Put a plug in the hose assembly to prevent oil loss and to keep dirt and debris out of the hydraulic system.3. Remove four bolts (1) that hold bypass check valve (2) in position. Remove the bypass check valve. The following steps are for the installation of the bypass check valve.4. Check the condition of the O-ring seal used in the end of hose assembly (3). If the seal is worn or damaged, use a new part for replacement.5. Install bypass check valve (2) in the reverse order of removal.6. Check the oil level in the hydraulic oil tank. If necessary, fill the hydraulic oil tank to the correct level. See the Operation & Maintenance Manual for the correct filling procedure.Disassemble & Assemble Bypass Check Valve
Start By:a. remove bypass check valve1. Make sure the outside of the bypass check valve is thoroughly clean prior to disassembly. 2. Loosen nut (7), and remove setscrew (8) from flange (2).
There is spring force against flange (2). When four bolts (1) are removed, the spring force will be released. To prevent possible personal injury, bolts (1) must be removed slowly and evenlyuntil the spring force is completely released.
3. Slowly and evenly loosen four bolts (1) that hold flange (2) to block (4). Remove the flange from the block. Remove O-ring seal (3) from flange (2).4. Remove stopper (10), spring (11) and valve (5) from block (4). Remove spacers (6) from the valve. Remove O-ring seal (9) from stopper (10).5. Remove plug (13) from the block. Remove O-ring seal (12) from the plug. The following steps are for the assembly of the bypass check valve.6. Make sure all internal parts of the bypass check valve are thoroughly clean prior to assembly. Check the condition of O-ring seals (3), (9) and (12). If the seals are worn or damaged, use new parts for