Someone searches how to bleed hydraulic disc brakes because the lever just went soft, and a blog offers twelve steps and a photograph of a syringe. If the bike is going to a guest this afternoon, close that tab. I'm not a mechanic for your fleet. I can tell you the mistake that takes a bike off the road for a week, because it is the same mistake in every hire shop that tried to be clever on a Saturday. What you can feel at the counter Squeeze the lever. It should meet resistance early and stay there. A lever that travels to the bar, or feels like a sponge, is a bike that does not get hired. Air in the line, a leak, or pads that are gone: you will not know which from the car park, and you don't need to. You need another bike. Look under the bike before you ride it yourself. Fluid on the caliper, on the rotor, or on the tyre is a leak. A contaminated rotor does not get wiped with the rag you use on chains and sent out. Pads that have drunk oil get replaced, not cleaned and hoped. Pads thinner than the maker allows are a workshop job, not a "it'll do one more loop." Why the internet's bleed is dangerous Hydraulic brakes do not share one fluid. Shimano and Magura, on the systems shops usually see, use mineral oil. SRAM, on the systems shops usually see, uses DOT fluid. They are not substitutes. Pour the wrong one in and the seals swell or rot, and the brake that was soft is now a replacement. Even the right fluid, in a hurry, with the bleed port open and the bike tipped the wrong way, pulls more air in. Then you have the same soft lever plus an afternoon gone. The maker's document for that exact model is the procedure: which port, which way up, how hard you may pull. This post is not that document, on purpose. If your workshop does bleeds, they already have the kit and the sheet. If they don't, the shop down the road is cheaper than a cooked caliper and a guest with no front brake. Topping up is not bleeding. If the system is low, it went somewhere. Find the leak or stop riding it. What the counter says "That one isn't going out. I'll put you on this one." Then a tag on the bars, the date, and what the lever did. Not a story from memory on Thursday. E-bikes make this more serious, not less. They are heavier, the guests are often faster than they meant to be, and a long descent into town is exactly when a soft lever shows up. A tour you designed down a hill assumes the brake you checked in the morning. The morning check is where this belongs, before anyone has paid.