2003 Escape brake booster check valve

Tuesday I took my Escape in for a tune up and had ignition coil replaced because I had a misfire on cylinder 3. Two days later my brake pedal is really hard to push but does stop the vehicle. Today I took it back to Firestone for a brake check. All they did was bleed the brakes. Well that worked for maybe 30 minutes before it started getting hard to push again. Firestone was closed by that time so I couldn't go back for them to check it. Well I decided to do some research on my own. First I did the test of pumping the brakes a few times with it not running and then press the brake and hold while I start it to see if the pedal goes down... And it does go down further. Next with the engine running I can hear a vacuum leak coming from the brake booster area. I think when he unhooked the vacuum hose he damaged the grommet maybe? My actual question is I'm pretty confident I can replace the grommet and the check valve myself. Is that all that needs to be done? Or does the brakes need to be bled again?

If that is all, then as long as you don't mess with any fluid to cause air to get into the hydraulic system, you shouldn't need to bleed the brakes.