Brake Confusion

[Eggo]

Not building any pressure on the rear brake system because the fluid is moving to the front brake reservoir this is what is turning the light on.

this makes a lot of sense thank you! got a new master cylinder on its way so hopefully be able to swap it later and fix the issue

 

[Eggo]

thank you so much everyone for your advice, seems like it was the master because swapped it, bled the brakes and now they’re so firm and that light has gone out as well!!

 

[70bigblockdodge]

thank you so much everyone for your advice, seems like it was the master because swapped it, bled the brakes and now they’re so firm and that light has gone out as well!!

Very good, glad you solved it/got the car stopping.