How long would it take to replace a brake booster with the cylinder attached. I believe the lines need to be replaced with brake fluid. Thanks, Brent

do you mean the brake hoses or the steel lines that attach to the master cylinder ? because if the steel lines need to be done that could take all day or more cause collateral damage is unavoidable, and nobody will want to do the work cause its miserable. if its just the flex hoses down at the callipers then about 3 hours including fluid flushing and bleeding For booster with master cylinder attached, add another 1.5 so 4.5 to 5.5 depending on the vehicles condition and how well its been serviced during its life, Keep in mind book time estimates don't apply to vehicles that are 30 years old.