Reporting back. I bought one, just used it. I had just recently replaced all calipers and pads prior. The thing works like a dream. I used it with some additional feedback from this thread. I know some were mentioning the motiv, but for 60 bucks vs 20, I thought Id chance this. Just to recap my procedure. Ignition on, started with the RR, RL, FR, then FL. I had a large piece of concrete I used to hold the pedal down for the rears. I could hear the pump run for both rears as it continuously pumped fluid out. Probably didnt need the check valve for those. The fronts are what I was more concerned with. I pumped the fronts a few times each. While doing this I noticed bubbles in the line at first, but the check valve worked and locked them in place. I pumped until I saw no air bubbles and used the piece of concrete to lock the pedal down then tightened. In retrospect a one man couldve probably been done utilizing a bottle and hose locking the pedal down with the concrete. I had no hose or bottle so i would've had to buy something regardless. So for 20 bucks I got some piece of mind in the check valve, that did work, and given the freezing caliper issue on the 4th gens, I plan on doing this at least once a year to help clear the lines and add fresh fluid. Took 10 minutes if that. Would recommend if you have no assistance and need any supplies to do the job at all. Thanks guys and gals, pedal is hard as it should be.