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Q: Rear brakes locking up.

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For about 2 years now the ABS light and brake light have been on. One month ago my rear brakes locked up. I cracked open the bleeder valves on the wheel cylinders and very little fluid came out, but enough to free up the brakes to get home. Since I replaced the rear brake hose and metal lines with new ones all the way up to the porportioning valve. Got that done today. Took for a test drive and ABS light and brake light are back on. I feel it is a matter of time before brakes lock again. What do I check or replace next? The porportioning valve?

My car has 186000 miles.
My car has a manual transmission.

If the ABS light is on, there will be diagnostic codes to access. Those codes will provide enough clues to dig into this. I would first obtain those codes simply because they will give a direct indication of what components to test. Once the ABS system is repaired, yes, the proportioning valve definitely could be a issue and that valve can be tested using external pressure gauges to see if the pressure being developed on pedal application, front versus rear, conforms with Factory Service Manual specifications. If you would like to schedule a diagnostic on the ABS system, simply request ABS diagnostic service and the responding certified mechanic will find the root cause behind the ABS malfunction and then move on to the rear brake issue if a fault there still exists.

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