TOOL AS- 4778634 - Caterpillar

Illustration 1 g00649636
Carry-Check Valve and Quick-Drop Valve (1) Carry-check valve (2) Quick-drop valve (3) Bowl cylindersThe carry-check valve (1) for the bowl and the quick-drop valve (2) are located on the top of each of the bowl cylinders (3). The carry-check valve performs the following functions:
Prevention of dropping of the bowl in case of failure in the cylinder lines
Prevention of high pressure in the hydraulic lines over the hitch
Prevention of movement of the bowl during modulation of the control valve spoolCarry-check valve (1) isolates the bowl cylinders (3) from the oil supply line. When the main control valve is moved to the QUICK-DROP position, the valve is vented. This allows the oil in the rod end of the bowl cylinders (3) to flow to the head end of the bowl cylinders (3). The bowl can then drop to the ground.