I have a CGC30 that is leaking hydraulic fluid out of the vent on top of the sump when the forks are lowered. The sump strainer has exploded so i replaced it and oil pours out. I have now taken the strainer out and it doesn't pour out as bad but still pours out a lot. The mast has 2 tall rams and 1 short ram. When the machine is running you can remove sump cap and the return line to the sump has excessive flow with all levers in the neutral position. Is this an open or closed hydraulic system? Why is all the fluid pouring out of the vent on top of the sump? Could it be a check valve or by-pass? Please help