A few months ago, I bought a 2015 Subaru Outback and the front left caliper was acting up, so I had a mechanic check it out. The mechanic recommended replacing the two front calipers (they were pretty rusty), the front-left brake hose, and then just greasing the rear caliper pistons.
I'm no longer hearing any weird noises now from the front-left and the brakes feel much smoother, but there's a couple differences that are throwing me off. The distance the brake pedal needs to be depressed before the brakes start to bite feels a lot longer now. I've also noticed a kind of hysteresis, where if I apply the brakes twice within a second or two, the second time I apply them, they'll start biting earlier.
Should I get the brake fluid replaced / bled? Could air in the brake lines explain this behaviour? (I assumed air in brakes line would had to have been bled but it's not explicitly listed on the bill I got.) Any other explanations?
The mechanic did paint the calipers too, just to delay rust, and there was a bit of overspray on the rotors, but I'm sure it got instantly scraped off by the brake pad.
Any advice would be appreciated!
Edit: To clarify, I did not get the pads replaced. The inspection done when I bought the car showed about 50% life left on the pads.
Follow up: You folks were right - They bled the brakes and the car felt like 90% better. They said the master brake cylinder might have been leaking a bit so they offered to replace it with no labor charge, so I sprang for that too, but it's hard to tell if that made any difference. Either way, it feels back to normal now, so thanks for your advice!
Sounds like you should start with taking it back to the mechanic and having them bleed the system properly.
If that doesn't resolve the issue, then find out what pads were installed, and what came out. Pad material affects how the brakes "bite", but what your describing sounds like once you have "pumped the brakes up" you get the bite you are looking for, which leads me to believe air in the lines.