My prius has rear drum brakes. The driver side bleeds fine but the passenger dose not have any flow. Only when i press on the brake and then let it go some fluid comes out. But only on the release. Any reason why it wont engage properly?
Do you have any brake system warning lights on? If there's a fault such as a brake fluid leak or air trapped in part of the system (maybe from previous repairs where the system wasn't properly bled) - then the brake control ecu might set a code and not allow brake fluid into the affected section. You likely have to read (then erase) any cofes before you can bleed the system correctly. Search for "flash codes" or "blink codes" in the forums. This can allow to (carefully) jumper two pins on the OBD2 connector which forces some ecu's to flash abbriviated codes on theirr warning lights You can also look st this thread that reviews several scantool apps and devices. Some are capable of scanning all systems on a Gen2 Prius. https://priuschat.com/index.php?posts/3290690 Posted via the PriusChat mobile app.
Simple terms....Sounds like you tried to bleed the brakes as if your Prius was an older style car. The Prius is smart and will cut off flow if it thinks there's a leak. You made it think there's a leak.