As far as I know, the only way to check the level is to suck it out with a specialized machine at the shop...not practical for the average DIY-er. If your A/C compressor is cycling on and off every 10 secs or so, buy a small can of R134a. Small cans are less than half the total capacity of the A/C system (27 ozs). The low pressure side is on the right-hand side if you are looking at the engine bay from the front. There's a black cap about the size of a dime covering the port. Nothing to it. Get the R134a with sealer if you suspect a leak. Always wear glasses/goggles since you really don't want this in your eyes.
