I did a disc brake swap on my 69 firebird and i am having some trouble with it. The system is installed correctly, and is adjusted what i would say is pretty well. But my problem is that when you step on the brake pedal you have about 4-5 inces of travel thats fine, but ALL of the brake pressure umps in in that last half an inch or so so the car immediatley jerks to a halt. and help would be really appreciated, i have no idea where to go from here. thanks alot.