I appreciate that you're not showing any gender bias towards your children.
In grade school, I decided to learn how to cook, do laundry, sew, and do other things that were traditionally female "duties." I caught a lot of heat for doing "girl things" but chose to ignore it. (I grew up effectively the lone male in a household with my mom and three sisters ... and decided I never wanted to have to depend on any female.)
When my children (a older son and younger daughter, roughly two years apart) were teenagers, I insisted they both learn motor vehicle maintenance by actually doing the tasks. In addition to routine maintenance like changing spark plugs, filters, and oil, I insisted they try a few more complex tasks like replacing brake pads/shoes and bleeding the brakes.
I really didn't care if they ever did it again. Instead, I wanted them to know enough to decide whether they wanted to do it themselves or pay someone to do it for them. More importantly, I wanted them to know enough to recognize when a shop was trying to rip them off with overly expensive or unnecessary repairs.
(I often tell about the shop that tried to tell me I needed new ball joints -- on a vehicle that had kingpins instead of ball joints.)
My son largely tried to avoid it while my daughter willingly waded into the tasks. Later, while she was in the U.S. Army, she found herself in the position of the go-to person for guys who had motor vehicle questions. On the other hand, my son now wishes he'd pay more attention and sometimes has to call his sister for advice and answers.
(This is a large part of the reason my son makes a determined effort to have his children spend time with me.)
On another note, I sense you're having some difficulty with terminology ... which is totally to be expected from anyone trying a new experience. A willingness to wade in, make mistakes, and learn is something to be proud of. (I'm more that willing -- even eager -- to absolutely jump down the throat of anyone demeaning someone's efforts to try and learn something new.)
So ...
Disk brakes => pads and calipers
Drum brakes => shoes and wheel cylinders
Finally, for everybody, I'm working on my dissertation on motorhome electrical systems ... but, it's summertime, with a period of good weather, so we're trying (working too hard) to make as much progress as we can on the house we're building. Please be patient, I WILL get back to it. (Actually, when the opportunity presents, I've been drafting and editing the next installment, complete with diagrams, offline rather than on-the-fly online composing without images.)
