The below diagram shows the correct position for the clamps.
Problem is owners change the clamps for ordinary hose clips but the OEM ones have a "tang" that locates in the box and prevents it from moving when you try and do it up and push against it. I'm guessing the front clamp is the problem. I used 1/4 inch drive extension bars joined together with a crosshead adaptor on the end, or just buy a suitably long crosshead driver.
HTH
