But do they know that you MUST bench bleed a new MC. Or do they throw the extra bits of tubing away with the instructions.

 

Here's what fishy, Mr. M said "replace a rotor and put in a new master cylinder"
Why would you only change one rotor and the master cylinder? What bearing does the master cylinder have on a the brake rotor? Yes a faulty caliper can cause the rotor to wear, but so would the pads, and from the description they weren't replaced.
And if this shop is reliable, take it back to them to bleed the brakes properly.

 

The pads where replaced. This was 5 months ago I can't really take it back now I was broke at the time and it was not a major problem. The master cylinder was replaced because when they bled the brakes the seal gave out and was leaking fluid. Not 100% sure what it was and I really don't care at this point I just ran into the bleeder valve issue when I was redoing it all myself.

 

My point was that you can bleed the cylinders until doomsday and it won't fix air in the MC.

If they replaced the MC they had to mess with the power booster, have you investigated that?

A needle nose vice grip is the shade tree solution.

 

If they did anything to the back brakes the spongy peddle can come from not adjusted rear shoes.

 

That's why you never let the pedal go fully down when bleeding the brakes. In normal use, you never push the pedal that far down, so that part of the bore never gets wiped by the seal. It can develop corrosion or roughness and then when you force the piston seal into that area it damages the seal.

Yes, I have had this happen to me years ago.

steve

 

That’s why I reverse flow when bleeding the brakes. And I never rebuild wheel cylinders or master cylinders, and always replace the brake hoses and brake calipers at the same time.
But that’s just me. I’m OCD about brakes.

 

Thanks for the help from everyone! I'll see what I can figure out this weekend when I have time.