I have a 76 bronco with PB, D44, PS, and disc up front. Question is The brake pedal will not come back up after you push it down. I replaced the master cyilunder and the brake booster, and bleed the brakes. Still the pedal stays down till you pull it back up. The brakes work fine other than that. Is there supposed to be a return spring there of any kind or what? Any Help?