Noticed excessive brake pedal travel and checked the brake fluid level. Found the soft rubber gasket on the master cylinder fill cap was split thru the middle. I'm not knowledgeable about how these brakes work but a split gasket can't be good. Right?

u need a new mastercylinder when u step on the brakes its not going all the way through to ur brake pads so u need to get a new master cylinder if its not that bad bleed the brakes and u should be good to go

Just got back from AutoZone with a new cap gasket (p/n 42072 by HELP!) and all is fine.

To robTypeR: Master cylinder? rob is correct.