Brakes - Rear Brake Groan When Cold
L-SB-0039-11July 1, 2011
Rear Brake Groan When Cold
Service Category
Brake
Section
Brake (rear)
Market
USA
Applicability
Introduction
Some 2010 HS 250h vehicles may exhibit a condition where a groan noise can heard coming from the rear brakes in cold weather and at low speeds. A new caliper slide pin and pad kit with anti-squeal springs have been developed to address this condition.
Production Change Information
Parts Information
Warranty Information
Repair Procedure
Repair Procedure Number 1
1. Test drive the vehicle to confirm the condition is present.
2. Perform the Disable Brake Control procedure.
A. Wait at least 2 minutes after the power switch is turned oft.
B. Disconnect the reservoir level switch connector with the parking brake applied.
C. Disconnect the cable from the negative (-) battery terminal.
D. Depress the brake pedal 40 times or more to return all of the fluid in the accumulator to the reservoir.
E. Check that the brake pedal cannot be further depressed.
F. Release parking brake
3. Remove the rear wheels.
4. Remove caliper slide pin No.1 (upper) and No.2. (lower).
5. Once the caliper has been removed replace the old pads with the NEW pads and install the anti-squeal springs
6. Apply a light layer of Lithium-base glycol grease to both slide pins as indicated.
7. Install the calipers and the NEW caliper slide pin No.1 (upper) and the original caliper slide pin No.2 (lower) and torque to specification.
Torque: 27 N*m (270 kgf*cm, 20 ft*lbf)
8. Reconnect the reservoir level switch first and then connect the battery cable to the negative (-) terminal.
9. Reinstall the rear wheels and torque to specifications.
Torque: 103 N*m (1050 kgf*cm, 76 ft*lbf)
10. Test-drive the vehicle and confirm that the condition is no longer present.
Repair Procedure Number 2
1. Test drive the vehicle to confirm the condition is present.
2. Perform the Disable Brake Control procedure.
A. Wait at least 2 minutes after the power switch is turned oft.
B. Disconnect the reservoir level switch connector with the parking brake applied.
C. Disconnect the cable from the negative (-) battery terminal.
D. Depress the brake pedal 40 times or more to return all of the fluid in the accumulator to the reservoir.
E. Check that the brake pedal cannot be further depressed.
F. Release parking brake
3. Remove the rear wheels.
4. Remove caliper slide pin No. 1 (upper) and No.2 (lower).
5. Apply a light layer of Lithium-base glycol grease to both slide pins as indicated.
6. Install the calipers and the NEW caliper slide pin No. 1 (upper) and the original caliper slide pin No.2 (lower) and torque to specification.
Torque: 27 N*m (270 kgf*cm, 20 ft*lbf)
7. Reconnect the reservoir level switch first and then connect the battery cable to the negative (-) terminal.
8. Reinstall the rear wheels and torque to specifications.
Torque: 103 N*m (1050 kgf*cm, 76 ft*lbf)
9. Test-drive the vehicle and confirm that the condition is no longer present.