The car is 11 years old, with only 67,000 miles on the car. The front brakes have new pads and rotors. The rear drums are worn but still within specs, and adjusted. The brake lines are clear of air bubbles. And yet, the brakes are spongy.
Might this be the power-assist module wearing out, or the master cylinder, or…?
3 possibilities: loose master cylinder mounting bolts
: Air in the lines
: defective master cylinder.4th possibility: Bad/loose front wheel bearing.
possible weak flex hoses at the calipers (or drums).
I’ll put in my $0.02 for the brake hoses. They really ought to be changed every 10 years. At that age, you start seeing them either become too hard and brittle, close up internally, or swell under pressure- which could explain the sponginess. I would change all 4 hoses, and bleed out the brake fluid entirely.
Mileage doesn’t kill rubber. Age does.