2004 GMC Sierra brakes problems

Defect

ON CERTAIN PICKUP TRUCKS EQUIPPED WITH MANUAL TRANSMISSIONS AND BUILT WITH EITHER PBR PARKING BRAKE SYSTEMS OR TRW PARKING BRAKE SYSTEMS, THE PARKING BRAKE FRICTION LININGS MAY WEAR TO AN EXTENT WHERE THE PARKING BRAKE CAN BECOME INEFFECTIVE IN IMMOBILIZING A PARKED VEHICLE.

Consequence

IF THE PARKING BRAKE DOES NOT HOLD, UNINTENDED VEHICLE MOVEMENT COULD OCCUR, WHICH COULD RESULT IN A CRASH.

Remedy

DEALERS WILL INSTALL A LOW-FORCE SPRING CLIP RETAINER FOR VEHICLES EQUIPPED WITH A PBR PARKING BRAKE SYSTEM. ON VEHICLES EQUIPPED WITH THE TRW PARKING BRAKE SYSTEM, DEALERS WILL INSTALL A REDESIGNED PARKING BRAKE CABLE ASSEMBLY. THE RECALL BEGAN ON JULY 29, 2005. OWNERS MAY CONTACT CHEVROLET AT 1-800-630-2438 OR GMC AT 1-866-996-9463.

Defect

CERTAIN TRUCKS, SPORT UTILITY VEHICLES, AND VANS EQUIPPED WITH BOSCH HYDRO-BOOST BRAKE ASSEMBLIES, THE HYDRAULIC BRAKE BOOSTER PRESSURE ACCUMULATOR MAY CRACK AND SEPARATE FROM THE HYDRO-BOOST ASSEMBLY DURING NORMAL OPERATING CONDITIONS.

Consequence

IF A SEPARATION OCCURRED AND THE HOOD OF THE VEHICLE WERE OPEN, FRAGMENTS FROM THE ACCUMULATOR COULD CAUSE INJURY TO PEOPLE IN THE IMMEDIATE AREA. THE PRESENCE OF THIS CRACK OR FRACTURED SURFACE COULD ALLOW THE HYDRAULIC FLUID TO LEAK FROM THE ACCUMULATOR CIRCUIT OF THE BOOSTER ASSEMBLY. THE LOSS OF FLUID WOULD CAUSE INCREASED STEERING AND BRAKING EFFORT AND A CRASH MAY OCCUR WITHOUT PRIOR WARNING.

Remedy

DEALERS WILL TEST THE HYDRO-BOOST ASSEMBLY FOR FUNCTIONAL OPERATION OF THE TWO-FUNCTION VALVE. IF THE HYDRO-BOOST ASSEMBLY FAILS THE TEST, DEALERS WILL REPLACE THE ASSEMBLY FREE OF CHARGE. THE RECALL BEGAN ON MARCH 23, 2005. OWNERS MAY CONTACT CHEVROLET AT 1-800-630-2438, GMC TRUCKS AT 1-866-996-9463 AND HUMMER AT 1-800-732-5493.

Defect

CERTAIN SPORT UTILITY VEHICLES, PICKUP TRUCKS, AND PASSENGER VANS FAIL TO COMPLY WITH THE REQUIREMENTS OF FEDERAL MOTOR VEHICLE SAFETY STANDARD NO. 135, ?PASSENGER CAR BRAKE SYSTEMS.? SOME OF THESE VEHICLES WERE PRODUCED WITH AN OUT-OF-SPECIFICATION BRAKE HYDRO-BOOST HOUSING RELIEF VALVE BORE.

Consequence

CONSEQUENTLY, THE VALVE O-RING SEAL MAY FRACTURE. STEERING EFFORTS MAY BE SLIGHTLY INCREASED WHILE BRAKING OR PARKING. UNDER CERTAIN DRIVING CONDITIONS, A FRACTURED SEAL MAY REQUIRE A SLIGHT INCREASE IN THE APPLIED BRAKE PEDAL EFFORT TO ACHIEVE THE SAME VEHICLE DECELERATION RATE AS PRIOR TO THE SEAT FRACTURE.

Remedy

DEALERS ARE TO REPLACE THE HYDRO-BOOST RELIEF VALVE. THE RECALL BEGAN ON JUNE 18, 2004. OWNERS SHOULD CONTACT CADILLAC AT 1-866-982-2339; CHEVROLET AT 1-800-630-2438; GMC AT 1-866-996-9463; OR HUMMER AT 1-866-486-6376.