Hello everybody, Our company bought an used Cat 924g loader. I think the last owner used just the bucket and they never lubricate/move the coupler. So now the coupler is stuck. We changed the both hydraulic hoses because the left hose was damaged. After this we tried decouple the bucket, but the pins not moving. The left hose is moving, and the engine is loaded when I push the coupler button. Any ideas how the coupler cylinder works? (part number1903085) I found a small valve attached on the cylinder, is it an one way valve or something similar? Is there any springs inside the cylinder? My idea is to remove the hydraulic connection from the valve and use a hammer to push the pins, but I affraid off the small attached valve, if is it an one way valve then the oil pressure is still inside the cylinder.
it's a check valve. I think you are correct. Most likely the cylinder rod is seized.
Hi Nige, Thank you for your answer! I connected the hoses as you can see on attached picture. The question is why is the left hose moving while I pushed the coupler button? So I think we have two options: 1. Remove the check valve from cylinder (part number 1903611), disconnect the hoses, and push the pins inside with some big tool. The oil will flow out from cylinder. 2. Push the coupler release button, and at the same time to try help pins with hammer.
I would say from your description that the hose to move the cylinder is pressurizing but the cylinder itself is stuck. Whether the cylinder is stuck internally or externally only you can determine. Some penetrating fluid (if you can access the area) plus press the button and try to help with a hammer (again if access permits) should get you where you need to be. From memory the only way to remove the coupler cylinder from the frame is to first have it retracted. So you are up against the challenge of having to move the cylinder.
Today I already removed the bucket from the loader. I found the broken bushing inside the bucket, and I also found that the coupler button have two positions The rear position moving the cylinder out - left hose. The front position moving the cylinder inside - right hose. Thank you for the diagram, it helps to understand that the button must have two positions.
I should have given you the complete hydraulic schematic.