COVER 5364629 - Caterpillar

Introduction
The Quick-Drop valve allows the bulldozer blade to lower more rapidly by sending oil from the rod end of the cylinder, to the head end of the cylinder in addition to oil from the pump.Test Preparation
Move the machine to a flat open area.
Lower all implements to the ground.
Stop the engine.Test Procedure
Use the following procedure to measure the actuation point of the quick-drop valve.
Illustration 1 g00696692
Measure distance (A) from the HOLD position of the bulldozer control valve to the float detent.
Measure distance (B) from the HOLD position of the bulldozer control valve to the activation point for the quick-drop valve.
Divide distance (B) by distance (A) and multiply the result by 100. The result is the percent lever travel for the activation of the quick-drop valve.Note: The quick-drop valve should activate at approximately 85 percent lever travel.Adjustment Procedure
Illustration 2 g00527725
Quick-drop switch in the bulldozer lift control valve section
(1) Shims
(2) Contact Pin
(3) Terminal screws
(4) RetainerIf the activation of the quick-drop valve occurs at the wrong point in the lever travel, then the activation switch needs to be adjusted. The activation switch is located in the bulldozer lift control valve section of the implement control valve. Shims (1) are on center contact pin (2) for this purpose. Movement of one shim from side (A) to side (B) of retainer (4) causes the pin to contact terminal screws (3) sooner. Movement of one shim from side (B) to side (A) causes the bulldozer control lever to be moved further before contact is made. Each shim changes the amount of lever travel that is required to activate the quick-drop valve by about 5 percent. Transfer the shims between the two sides. Do not remove shims or add shims.