We just had our car and they replaced the front wheel bearing. The next day our break peddle went down to the floor. Is there something they could have done or not done to make us loose brake pressure over night?
Yea, they may have bumped a vacuum hose that is now loose. If you can find it (listen for a hissing noise) you may be able to put it back on yourself.
Are you saying that you picked up the car after this service, drove it and it was fine, and only now you have a brake problem?
Check your fluid level.
If you pump the brake pedal does it firm back up? And if you pump the brake pedal & it firms up will it hold or does it then sink to the floor (even if slowly).
Your options are either that you need a new master cylinder in which case this is probably a coincidence. Or that in pulling the caliper (which I’m pretty certain they’d have to do as part of the wheel bearing), they loosened your bleeder screw and either left you with a leak or with air in the brake lines.
Grab hold of the top of the tire and shake vigorously. If the wheel seems loose, the bearing was defective or improperly installed. The movement is pressing the brake pistons far back into the caliper so you have excessive brake pedal travel. Does the pedal pump up if you press it a couple of times?
Check the brake fluid reservoir (under the hood, near the windshield, in front of the driver) and make sure it is full up to the line in the reservoir. If it is low, look beneath the car for evidence of fluid leakage in the vicinity of the repair.
The brake problem a day after repair on a wheel COULD be a coincidence, but that is not the way the smart money is betting.
A loose vacuum line would could make the brake pedal very hard to push, it couldn’t make it sink to the floor. That has to be fluid leak (internal or external) or air in the hydraulic system.