Re: Brake pedal drops to the floor
According to the above information, my new master cylinder is for a manual brake set up! Maybe that's the problem..?
You can still use a manual brake MC with a booster, but as discussed, you need to have the correct rod from MC to booster for sure. Measure your old MC and rod and make sure the new MC rod or rod with extension is the same exact length as your original setup relative to the booster. If the rod is too long, it won't let the the MC piston retract fully.
You should be able to plug both ports on the new MC and get a firm pedal, then the MC is good. These things are tested before sales, even the rebuilt ones, so it should be ok, but I've heard sometimes they aren't.
These pedal collapsing to the floor problems are almost always an issue with air in the system somewhere. Unless I missed it, not sure you mentioned if you bled the MC properly prior to installation.
'69 Z/28, Lemans Blue/White Stripes, DZ302, Tremec Magnum, 4.10, Procar Elite Seats,
Custom Upholstery, Dynatech headers, 17" VWW V45's, 235/45, 275/40, C5 Front Brakes