So i keep getting this problem with my brakes. Ive gravity bled the brakes, pressure bled them, bled the master, and even taped on the combo valve when i hold pressure down on the brakes but i still have a spongy pedal. When the car is running the pedal almost goes to the floor. Any ideas what i should try next. I dont no how old the rubber brake lines are for the front discs and i no theyre known to collapse when they get too old. when you pump the pedal up the resivour shoots the brake fluid back up in. or at least that appears to be what is happening. i see no air bubbles what so ever and theres no air bubbles when i bleed the brakes. any ideas where to go next?

 

A little history would help, as always.

But if I were to fill in the blanks, I'd guess that the master cyl has been changed out here lately; or at least, the system has been allowed to let it run dry. In which case, you MUST MUST MUST MUST remove the MC and "bench bleed" it. Reason being, the way it's mounted in these cars, the line fittings are NOT at the highest point; meaning, as long as it's in its installed position, then once ANY air gets in there, it will NEVER EVER EVER EVER find its way out. You can pressure / gravity / leech bleed the thing every single day from now until Doomsday, and twice on Sundays just for good measure, and the air will STAY RIGHT WHERE IT IS making your pedal spongy until the End of Time.

Gotta bench bleed the MC.

 

I thought that would be the ultimate response. Unfortunately that'll be on the to do list this weekend. Thanks for the diagnostics.