Most importantly, keep the tool clean and free of debris, especially all the intake and exhaust ports. Over time, it may be necessary to clean the combustion chamber with a simple 10 minute procedure.
In general, the Grex cordless tool is designed to be as easy to maintenance as a pneumatic nailer. For example, accessing the piston driver assembly is exactly the same as a pneumatic nailer. Simply remove the 4 bolts on top and then take off the entire top cap assembly. Other normal wear parts are also easily accessed via the top cap or rear cap of the handle. The easy maintenance makes this tool field serviceable, saving you both time and money.