I'm going to change my brake pads for the first time and was wondering how to do it correctly. I have an 86 Toyota Pickup and in the Haynes manual and other Youtube videos people usually just depress the caliper and make sure that the brake fluid reservoir doesn't overflow when the fluid is pushed back through the lines. But a mechanic friend of mine said that pushing the fluid back through the line can ruin the master cylinder. He suggested clamping the brake line off and then opening the bleeder valve when I depress the caliper. Is either way okay and what is the likelihood of ruining the master cylinder if I just push the fluid back into the reservoir?