Komatsu PC88MR-10 Shop Manual page 166

10 Structure and function
Control valve
When right and left travel valves are operated (including when one side travel is operated)
Since spool (1) is located the divided position, LS circuits (PLS1) and (PLS2) are divided from each other.
Pressurized oil (PLS1) is drained through filter (a) at the end of LS bypass valve (3) on (P1) side and
orifice (b) to tank circuit (T).
Pressurized oil (PLS2) is drained through filter (a) at the end of LS bypass valve (2) on (P2) side and
orifice (b) to tank circuit (T).
10-88 PC88MR-10