Installing a new hydraulic motor

[ontheroad10]

So in returning home, mu hydraulic motor failed on my 2013 3100rl Montana. I'm in a remote town outside Memphis. I called someone to take a look and was told they could close the slides so I could travel, but the motor had to be replaced. After trying for a day trying to find one locally, I was able to get one overnighter from Lippert. Where I am, it is very difficult to find a technician to come out, so I did the job. Upon trying it out, it worked fine in getting the rig off my truck, but the started grinding and heating up. I tighted the screws and tried again with the same result after a while. In reflecting on my work, there were 2 orings that were under the bolts that were difficult to get on so I didn't. Also there were 2 at the contact point with the reservoir, but the kit came with 1, so I used the 1.
After spending $1300 for the part, I sure don't want to ruin it. Any insight would be appreciated