CASE 1366547 - Caterpillar

Hot oil and hot components can cause personal injury. Do not allow hot oil or hot components to contact skin.
Never remove the fill/vent plug from the hydraulic tank if the oil is hot.Air can enter the system and cause pump damage.
Note: In addition to an oil level gauge, your machine may be equipped with an automated function for checking fluid levels. Refer to Operation and Maintenance Manual, "Monitoring System" regarding the automated system.
Illustration 1 g03844779
The hydraulic oil tank is on the right side of the machine.
Park the machine on level ground.
Open the access door on the right side of the machine.
Illustration 2 g02024082
(A) High temperature range
(B) Low temperature range
For a cold machine, maintain the hydraulic oil level in the low temperature range (B). For a machine that is at normal operating temperature, maintain the hydraulic oil level in the high temperature range (A).
Close the access door. Note: Perform Step 5 through Step 8 if the oil level is low.Note: Refer to Operation and Maintenance Manual, "General Hazard Information" for information that pertains to Containing Fluid Spillage.
Illustration 3 g02024028
Pressurized system!The hydraulic tank contains hot oil under pressure. To prevent burns from the sudden release of hot oil, relieve the tank pressure with the engine off by slowly turning the cap approximately 1/8 of a turn until the cap reaches the secondary stop.
Illustration 4 g02275615
Filler cap
(A) LOCK position
(B) PRESSURE RELEASE - START position
(C) PRESSURE RELEASE - END position
(D) OPEN position
Release the pressure that may be present in the return hydraulic circuit with the following procedure. Refer to Illustration 4 for filler cap positions.
Turn the filler cap counterclockwise, with no downward force applied, and move the arrow from position (A) to position (B).
Release the pressure for a minimum of 45 seconds by moving the arrow from position (B) to position (C).
Push the center of the filler cap down. Without tilting the filler cap, move the arrow from position (C) to position (D).
The hydraulic tank pressure is relieved. Remove the filler cap.
Add oil if necessary. See Operation and Maintenance, "Lubricant Viscosities"
Check the O-ring seal of the filler cap. Replace the O-ring seal if the O-ring seal is damaged.
Clean the filler cap. Tighten the filler cap on the hydraulic tank to position (A).