All those parts were included with the pads. They are the Carquest Premium Brakes. Best ones they had in stock for this vehicle at the time I was there and all 4 wheels are the same, except for the pad size.

 

OK, good. Sounds like there may be some air in the system somewhere. Might have to gravity bleed each wheel separately for 5 minutes or so, then bleed as normal. Only takes one, maybe two, times at each wheel after gravity bleed.

 

How does air suddenly get into the system? Can that happen from just replacing pads?

 

Air cannot get into the system unless it is opened, or there's a leak. If there is an air pocket in the system, pedal travel can be mushy and/or inconsistent. Pushing the caliper pistons back in when installing new pads will move the air pocket, but it will not allow air into the hydraulic system. There's also the possibility of air trapped in the ABS unit. The usual bleeding techniques such as pumping the pedal, gravity bleeding and power bleeding will not work. The only way to bleed it out is to perform the "automated bleed" with a capable scan tool.

 

The entire system has been flushed several times, including once by the dealer 2 years ago and multiple bleeds since then. They said it didn't need the scan tool, which surprised me. I will have this mechanic bleed the brakes on Monday because that usually helps in these situations.

Now what happens if the bleeders are rusted?

 

If it's been bled as often as you say, the bleeders should come loose very easily. All 4 bleeders must come loose. Bleeding at the line where it enters the caliper will not allow air that's already in the caliper to be bled out. If the bleeders don't loosen up, or they break off in the caliper, the caliper needs to be replaced. Each wheel must be bled, then perform the automated bleed. Then bleed all 4 wheels again. If there is air trapped in the ABS unit, the automated bleed purges the air into the lines, so each wheel needs to be bled again afterwards. The second bleed can take a while because any air that was in the ABS unit has to exit from the wheels. I usually do a gravity bleed after the automated bleed and let each bleeder drip for 10 or 15 minutes, keeping the master cylinder full the entire time.