Is the brake master cylinder as easy to replace as it looks? Two bolts, two lines, and an electrical connector. My pedal has been getting worse, it will slowly push down when I am holding the brakes.
Is this a normal failure?

 

Yes that is a typical failure. A fairly easy job just make sure you bench bleed it before installation. Just watch a u-tube video the bleeder kit can be purchased at any auto parts store.

 

I have the Motive bleeder kit. I have searched the big web for install instructions for the C7 Corvette Master cylinder, can't find any video. Not a big deal, I just thought I would find something. I guess I should make a, master cylinder replacement video for the C7.
I got it installed this morning. Start by removing the hose that plugs into the brake booster, and the power brake booster pump, the can shaped thing just in front of the reservoir. Two bolts that hold the master to the booster, 13 mm. The two brake lines, 13 mm. Kind of a pain in the butt to get to. I used my Motive bleeder to bench bleed the new master. Fill the master reservoir with fluid, put the Motive cap on, 1/2 a pump is enough pressure. I installer two clear bleeder tubes to the new master, very easy to see when the air bubbles stop flowing. Remove the Motive. I left the clear tubes on the new master, then installed it on the car. Remove the clear tubes connect the two brake lines. Connect the front brake line first. Fill the reservoir. The hardest part is connecting the two brake lines to the new master.
Took it for a drive, so far my pedal seems good.

Nothing obvious, maybe just weak O-ring seals. If I could get the seals, it could be rebuilt.