2008 Jeep Patriot Sport 2.4 FWD
Master cylinder ran dry because the rear wheel cylinder leak brake fluid on the drum brakes. Will I have to bleed the master cylinder first then bleed at the wheels with ABS scan tool. (Also have a code P1607.)
First off, don't shout at us, please.
Where are the brakes leaking? If it's from only a brake line, the master cylinder is probably fine. Fix the brake line leak, bleed the system, and if the pedal still sinks after properly bleeding, replace the brake master cylinder. The check engine light is illuminating for something that's not relevant to the brakes.
You may need a scan tool in order to bleed the ABS system.
Will I have to bleed the master cylinder first then bleed at the wheels with ABS scan tool.
Yes the whole system.
Also have a code P1607
it's unrelated to your brakes. Please post a new question if you need help with that.
https://www.jeeppatriot.com/posts/1901856/
P1607: Set Condition
Upon power up, the Powertrain Control Module (PCM) compares the change in engine coolant temp sensor since last engine shut down and compares it to the amount of time the engine was turned off. If not enough time has occurred to account for the difference in engine coolant temperature then the fault will set. Two Trip Fault. Three good trips to turn off the MIL.
https://www.allpar.com/threads/code-p1607-today-with-cel.239620/
I've observed with Chryslers it's often bad electrical connections causing issues. For example, in this case I would suspect a bad electrical connection between the engine coolant temperature sensor and the PCM causing false coolant temperature readings.
