The old pump was over heated and the original installers didnt apply thread locker to the bolts on the mounting flange so the entire pump had to be replaced. Check out the pump tear down video • PTO hydraulic pump tea...
I realize this is 4 years after you did the work, but there needs to be a bracket supporting the rear of that pump. The reason the bolts came out of the flange is the pump bouncing on the flange stretched the mounting bolts, allowing the bolts to back out and fall out of the mounting flanges. You are lucky the aluminum mounting flange didn't strip out.
I really need to know too I had issues installing it and low pressure the old pump bind up and I replaced it but no pressure. I tried to adjust the pressure relief valve and still nothing
