Do you have more fluid in it than you did? I'm thinking you may have hooked onto an implement with a cylinder extended, thus adding hydraulic to your system. Is that possible?
My Farmall M is my loader tractor - it has a live pump and uses the belly pump for storage. I didn't have enough fluid to have the loader up and use hydraulics on implements. I ended up hooking a hose to the fill and running that to a tank I mounted on the frame rail. That pump isn't very big for holding much fluid. With the amount that a live pump can put out I had lots of random puking going on until I added that tank for expansion room.