Hey guys,

My Cobalt hit 160k miles last week and shortly after, my brakes became spongy and now lose pressure after sitting in the driveway for more than a couple hours. When I return to the car, the brake pedal is all the way up, but hard as a rock until I start the car. When driving, it has little bit more travel than it used to until I reach the point where it begins to stop, and I hear a "squish" when braking, this lead me to replacing the Master Cylinder.

I have everything lined up and will be purchasing the parts on Saturday, but I wanted to check with anyone who's experienced this behavior to ensure I'm going down the right path and replacing the actual issue, not just blindly replacing parts and crossing my fingers.

If I'm correct and I need a new Master Cylinder, do I have to bleed the ABS Module/Reservoir, and if so how would I do this? I do not have access to a Tech2 to electronically activate the pump, but is this necessary when replacing the Master Cylinder? I don't want to cut corners and I want to do this correctly, but taking it to a shop is out of the question due to the lack of funds to afford labor.

Unfortunately I have limited experience in this particular field and will be getting assistance from some friends who've done this before, but they do not know about the ABS Module/Reservoir bleeding necessities either.

Any and all assistance is welcome and much appreciated.

Thanks!

 

i had this problem, had to re bleed my back brakes, thats it.

 

Awesome, thanks for the idea, I'll tear apart the drums and see if there's anything going on back there.

Thanks man!