2004 Chevrolet Avalanche brakes problems

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.