I have a 2020 Prime Limited and encountered an odd thing during my brake fluid flush. I have done fluid flushes on many makes/models but this is the first time trying a flush on my Prime. My first step after disconnecting the 12v battery and pulling the wheels is to use a large syringe to drain the master cylinder reservoir. Usually there is a mesh strainer that you need to remove to allow access to the fluid below. On my Prime I could not see a mesh strainer and there seemed to be a hard plastic piece just a few mm inside the master cylinder. Looking this piece over, I saw no way to remove it so I was left pulling only about 50 ml from the master cylinder. Is there a trick to removing the plastic piece? For this flush, I opted just to drain down the master at the first wheel and refill it with fresh fluid till I saw fresh fluid coming out using a vaccuum system, followed by repeating the same thing at each wheel topping off the master with fresh fluid as I went. Brakes feel fine afterwards, but I could have saved a bit of fresh fluid which I needed for my other cars that were in line for the same service that day. Thanks for the input !
Step one (barring use of Techstream) according to Toyota, is to put the car in “invalid mode”. There’s no 12 volt disconnect. It’s also a good idea to have the 12 volt on a charger too, due to protracted time “on” (not full “ready”). It sounds like you’re ok though, if brakes feel fine and no warnings/codes. there’s some tips in one link in my signature. They’re gen 3 specific but mostly applicable I think (on a phone turn it landscape to see signatures). also, I’ve attached gen 4 repair manual excerpt. Do check out the link in my signature as well: the Toyota document is very awkward. Even stuff like the order to do the four corners: what could be explained in about 10 words (or one picture), takes them about a page. Ditto for the invalid mode procedure: @NutzAboutBolts video explains much better, noting the extra brake pedal pushes when shifting to Neutral. And: the parking brake HAS to be on.
