This document provides instructions for removing and installing inlet and exhaust valve springs on a Caterpillar 320D L excavator. The key steps are:
1. Use valve spring compressor tools to compress the valve spring and remove/install valve keepers and springs while ensuring the piston is at top dead center.
2. Clean and inspect all cylinder head components before installation and replace any worn or damaged parts.
3. Lubricate valve stems before installing valves, springs, retainers and seals in the proper order and orientation using tools as needed.