Interesting conclusion you have here? How many miles had you driven on your original clutch?As someone who has had to replace the clutch in my 2012 Frontier twice now, I would highly recommend that you replace both the master and slave cylinders ASAP. These are failing internally and causing premature clutch failure. I did not do this the first time so I ended up replacing the clutch a second time. Up to you but it is literally a 20 min job to change them both and bleed them. They are also pretty cheap on Rockauto.com.