Vehicle: 2010 Mazda 3, L4-2.0L, Automatic Transmission/Transaxle
Problem: The customer was concerned that there was possibly some air in the brake system. The brake pedal was dropping about two inches after a complete stop. Another shop had previously replaced the master cylinder and calipers for this problem, but the brake pedal still dropped.
Case Details: The technician put a called ALLDATA Tech-Assist for some advice. The Tech-Assist consultant recommended to first block off each wheel at the caliper hose and see if the pedal firmed up. If it did, the technician was to release each wheel, one at a time to find the offending component. If the pedal did not firm up and the master cylinder is verified good, then he advised that the ABS hydraulic unit could be faulty.
The technician tested the brakes as suggested and found the ABS module (which included the hydraulic unit) to be the culprit.
Confirmed Repair: The technician replaced the ABS module and bled the system. After the repairs, he took the vehicle for an extensive test drive. At no time did the brake pedal drop when the vehicle was at a full stop. Problem fixed!
The ALLDATA Tech-Assist team fields cases like this every day. See how Tech-Assist can help your shop save time and money with on-call diagnostic support from ASE-certified Master Technicians. More Tech Tips
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