A drill went through my brake booster back in July. My '05 sienna came out of the shop just fine. 2 weeks later, I drove the van home from one shift just fine, heading out to my second shift, even in the driveway, I couldn't depress the brake pedal. I drove for maybe 15 minutes, when I smelled something awful, and when I let my foot off the gas the van stopped. I could just barely touch the brake pedal before the van stopped. After sitting for an hour, and calling my mechanic, the brake was fine. My husband thought the shim on the brake pad, which fell and a tab was mashed against the rotor, we thought that was the issue. The next day, same hard brake pedal, same smell, same ol' the van wanted to stop as soon as I let off the gas. My husband replaced the caliper on the passenger side. It did okay for a little bit, the brake pedal would get hard, but no smell, and that would come and go. Another hard brake pedal, burning type of smell, and he called some friend who all told him it sounded like the brake lines were collapsing. Driver and passenger brake lines were replaced. Brake fluid was ran clear when lines were bled. Off and on until today,(10-9-19), hard brake pedal, no smell, problem would correct...no rhyme or reason for hard brake pedal. Today, on my way home, the brake pedal got hard while I was driving, and there was some type of "wobble" and a vibration. The "wobble" I was feeling, it was like I was driving on a tire that wasn't totally round, like there was a flat part to it. There was that awful smell again. I was in the post office parking lot, when I returned to the van...I almost couldn't put it in reverse. When I did, and let up off the hard brake pedal, the van wouldn't roll back. I had to give it quite a bit of gas to get it to go in reverse. Dropping it into drive, was that "wobble", and it was like the van didn't want to go any faster than 10mph. It's been sitting in the driveway for an hour now. I'm not sure if I want to go turn it on and check the brake pedal or not. The caliper is new, the brake lines are new, google led me to something about a master cylinder. I checked "symptoms" and what my van is doing doesn't match up. I did get a check engine light on again, but I'm sure its that p420 code or whatever for the catalytic converter, that's been coming on since May. I don't think the cel has anything to do with the master cylinder. My brother told me over the phone that it sounds like the caliper may have somehow been installed incorrectly or somehow some trash got into the brake line. But its always that passenger side giving me issues. I never had any issues before I got the new brake booster....I don't think its that, because back then, the brake pedal went way down toward the floor and the van wouldn't stop. Does anyone have any other clues that might send me in the right direction, and get me to feel safe on the road again?