I am an experienced wrench puller although I only work on brakes for myself and not commercially. From the days when all four corners had drum brakes, I remember one of the most annoying and scary tasks was bleeding the system. Not that it was that hard, but getting good help was hard and it took two to get it right. It's so awesome I had to show it to friends who are professional mechanics who didn't know about it. I had to replace a wheel cylinder on my old Tahoe (11" rear drum brakes - all my cars are old enough to vote) and after installing the new wheel cylinder, reassembling and adjusting the brake, I removed the stem. breather and replaced with a breather. I carefully screwed the bleeder in with a deep socket and a 1/4" ratchet until it bottomed, rotated it 1/2 turn and refilled the reservoir on the master cylinder. After five pedal strokes, I pulled the trap hose and can out of the bleed screw, tightened it, filled the reservoir, done! That's so fast. , (ah what do you say?) re-inflate and hold etc) Honestly I have a small number of cars, all a few decades old or older, and I'm obsessed with them. You should bleed the brake system every few years to remove the old brake fluid and any moisture that may have gotten in, this makes the job easier! Screw in the WD-40 after I tighten it before putting the cap on as brake fluid attracts water and water is inevitably corrosive. on the. So the check valve will survive next time. I installed 639580 Speed Bleeders on the front calipers and will be replacing the bleed screws with them at the park.