Hey, S1B, welcome to the OTT family! (Is that Sulphur anywhere near Lake Charles, where I grew up, or someplace like to "hell and brimstone"?
)
I don't know about the BX, and have only a tiny understanding of hydraulics. So my comments are intended to keep you moving forward until the gurus can chime in.
Hydraulic systems (closed ones) are generally self-purging, but can easily get locked, much like fuel systems that get vapor-locked. So when my loader, for example, gets air in the system, if I raise and lower it a few times, it works the air bubble back into the reservoir, and filling the system with fluid.
So: what steps did you take to prevent air entering the system? (I expect, since you replaced the pump, plugging all the lines wasn't possible.) If you know that air is going to enter your system, then making allowances for it to exit will help to get the system functional after it's been serviced (after the repair is complete and you're ready to button it up).
Look at your system and find a place above the pump where you can vent it. With the system closed and filled to capacity (NOT OVERFILLED!!!), open the system and purge the air.
This might be a plug; it might be a hose or fitting. With the pump running (on your BX, prolly means the engine is running and the hydro motor running), open (like, unscrew a fitting or hose coupling) and let it pump out the air -- which may be some hydraulic fluid before the air comes out -- until hydro fluid comes in a steady stream/flow/gush. Close the opening, shut down the pump, and refill the reservoir. Then try the hydraulics.
If the symptoms are the same (nothing works! <sob>) then try the steps one more time before punting.
If your system works now but doesn't work properly, try exercising it to work the air out. (Exercising meaning extend and retract the hydraulic components to move the air through the system and back to the reservoir.)
Best wishes, and good luck getting the attention of the gurus to get you on the right path! Please keep us posted on your progress!
