Benjamin Marauder leaking problems.

Hi guys! I have had a Marauder for almost a year and a half and I rarely had the chance to use it but had a good time when I did. I really stopped using it when it began to leak air. I am sending it in to Baker Airguns to have it fixed and sent back. How do I prevent my marauder from leaking in the future? Also, the zoom adjustment knob on my scope wont move. Unless this will hamper the performance of my scope in any other way, I would rather not spend any more money on a scope. Please let me know what you think!!Thanks.
 
well the main thing about a leak is where and it just a simple seal replacement I take my gun apart once a year and replace the rings and apply a fresh coat of silicone grease
also to avoid leaks your really want to make sure you keep air pressure in the gun for storage as well as some way to remove moisture when you pump or fill it so any internal parts don't corrode and cause a leak
 
yes there is as well as you can look up a parts diagram from Crossman's yourself witch is basically a schematic of the gun and part numbers for reference all you really need is a few wrenches and your good to go I do not tare it down too all components just basic air tube innards to make sure the seals stay as well as the air port to make sure theres no gunk witch is between the tube and breech.. and if you read the manual the gun came with it says to at least keep 1000 psi in the gun for storage so that the seals stay against the metal.
 
I I'm. Having issues with leaks now with my .25. Started with a bad o ring that went bad from air tank extension that I bought from talon tunes . Com. I contacted him for the size of ring and he wasn't much help. I been guessing the size and I'm still leaking after every test and now I see I'm leaking air out the end of my barrel. I need help with this guys big time. 
 
The cut outs for the air gauge, the trigger slot and the air tank fill screw in have unfinished sharp edges.
I had that problem and replaced the air tub just to get one that was as poorly finished as what I had.
I used a small rat tail file to remove all the burrs then polished it with a 1200 grit 1 inch hone on a drill.
I did a light polish on the thread end and this ended the problem.