RV Repair: RV A/C, rain gutters, ford chassis

Question
I have a 1996 Winnebago, Itasco, on a Ford Chassis. It has a Coleman T/S, 13.5 roof a/c. It gets real cold, so, it works great. But, when it is parked directly level, the a/c starts to leak inside. I just checked the four bolts inside the rv and they were almost hand loose. I tightened up on them, but how tight can you make them? it was real loose, I am afraid I will get them to tight and damage the roof.
But, when you are parked on a angle it drains off on the roof, down the rain gutters and does not leak inside.
I had the gasket replaced a year ago.
What do you think? I read that most RV a/c leaks are  the bolts working loose.. Maybe I just need to tighten up more. Can I damage anything making it to tight?
I thank you for taking your own time to assist us, your talent is greatly appreciated by this individuel.
Don.

Answer
Don,

   You are correct in your diagnosis.  When tightening the bolts that hold the upper unit to the RV you want to compress the gasket about 50%.  When you are level the water that the evaporator is pulling out of the air is running out of the upper unit and back towards the gasket.  When you aren't level it runs out and away from the gasket.  I hope this helps and good luck with your repair.  Thank you also for your kind words.

Darren