Been a while since my last update. Too hot to go wheeling in the low desert right now.
My 4Runner let me down for the first time in the last 4.5 years and 45k miles. Well, kind of. I was still able to limp home through the neighborhood streets from the grocery store. I went to back out of the parking spot and found I had no brake boost after the first pump. Boost would take a few second to build back up, so I suspected a leaky/bad booster. After doing some research, I opted to just put a new booster in given there were no vacuum leak symptoms in the system.
I couldn't justify the approximate $900 Toyota part this time. So I went with a Napa remanufactured unit for much less. Budget woes.
New booster fixed it! This job was much easier than I anticipated. The most difficult part was ensuring I took care to remove the booster with the MC hard lines all still attached to the MC. I think if I would have cracked open those lines, the job would have gotten a LOT harder. To make it work, I removed all of the brake hard line connections at the firewall as well as the ABS unit, and that gave me enough room to pull the MC back while I wiggled the booster out. Probably a 2 hour job for me, and I take my sweet time.
Also - New battery too! Terminals/poles all cleaned and freshened up with a wire brush and dielectric great. I saw while I was working in there the battery was starting to spit some kind of junk out the top and a bit of usual corrosion on the positive terminal (my 2nd terminal now), and the charge it was holding was steadily dropping the last few times I noticed when charging it. So I ran to the big C store and got my free replacement days before the warranty expired. They aren't the best batteries, but they are the best warrantied batteries if you live in a hot climate that cooks car batteries in ~2 years.
*MAINTENANCE PERFORMED @ 215k miles. (to future self)