K 1500 Suburban 4WD V8-393 6.5L DSL Turbo (1994)
Vacuum Brake Booster: Testing and Inspection
Slow or No Release
1.
Faulty pushrod adjustment.
2.
Binding linkage.
3.
Blocked passage in power piston.
4.
Air valve sticking shut.
5.
Broken piston return spring or air valve spring.