A draft beer faucet being "hard to pull" or "sticky" usually indicates a cleaning issue. Either cleaning has not being done with a chemical specifically designed for draft beer cleaning, and/or the faucet is not being disassembled and thoroughly cleaned.
Pump water mixed with a cleaning chemical into the beer hose and let it soak for the time prescribed by the chemical manufacturer.
Then, thoroughly flush the beer hose with water to remove all traces of the cleaning chemical.
The last and most often overlooked step is to soak the keg coupler and faucet in water with cleaning chemical then brush them clean with a cleaning brush. Rinse them completely clean with water.