If you are only getting to 45 psi, you have a problem with either your reed valves or piston rings/cylinder assembly. If you feel comfortable taking it apart, removing the head(s) on the pump will let you inspect both to see which is the problem. The reeds on the valve plate have to be in perfect condition. Buildup, broken or bent reeds will prevent them from sealing so air can be pumped into the tanks. If the seal (oiless) or rings (oil lubricated) around the piston are damaged the same result will occur. These can be indicated by excessive wear marks on the cylinder or stray peices on top of the piston. Both are simple fixes and fairly inexpensive. Without your model number I don't know which parts to recommend. On Ridgid's website they have an excellent parts lookup system and you can order from them or use the part numbers to check other websites for prices.