Ford 4400 with front hydraulic pump and loader. Something is wrong with the hydraulic system, i am fairly new to the hydraulics and need a little guidance. The hydraulic system quit very suddenly not a slow failure. Once it went out it wouldn't move the loader, or even think about moving the loader like i had 0 or near 0 pressure. I took off the main "in" line at the valves, when the engine is turned over it squirts fluid out with enough force to push my hand off the line. What i need to know is how the bypass system works on these models. Does the pump have its own pressure relief or is that in the valve block. Basically i need to know if my problems are at the pump or in the valves. My plan is to test the pressure by putting a gauge on the end of the main "in" line and turn over the engine. If i get good pressure then its the valves, if not its on the pump end. However if the pump does not have its own pressure bypass im not sure what will happen when i block off the line and turn the motor over, dont want to strip splines. Another option if the pressure relief is in the valve block is to remove the return line and turn over the engine. If fluid comes out then the pump is atleast putting out enough pressure to open the bypass and the problem is probably the valves. Not sure what that pressure is though.
If anyone can either confirm my thoughts or correct them it would be much appreciated.
If anyone can either confirm my thoughts or correct them it would be much appreciated.