AC Line fitting

I am trying to replace my liquid line,and accumulator in my 2000 xj.
i have the ac line tools but am still having trouble. The liquid line to the accumulator fitting seperated easily and reconnects easily, but the manifold line to accumulator was VERY stubborn to disconnect and now WONT reconnect. The liquid line to the condensor wont budge...
Can i spray those spring fittings with some kind of lub to aid in there disconnect/reconnect.
Is there some sort of trick...

try inserting the fitting part straight in, then wiggleing it to get the threads going