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Customer complaint is when first started in the morning brake pedal is rock hard and will not depress and apply brakes. If she pushes on pedal and puts it into gear fast car will start rolling with no brakes. She throws it back into park, tries again and it's fine. Never does it at highway speeds or at stops.I cannot resimulate the complaint. Now she says it did it once at 70 mph when she had to hard stop. Keep in mind this has an electric vacuum pump not the mechanical one that has been destroying brake boosters with oil intrusion. Vacuum pump is working, can anyone think of another problem besides an abs wheel sensor falling out? I do not have a bidirectional scantool to watch all 4 wheel sensors.
If you don’t have a scanner that can read live data I’d tee in a vacuum gauge between booster and line see when problem occurs if you have vacuum to booster or not. If you do I’d say booster is at fault if not you will need to check vacuum pump circuit
Thank you, I do have an actron II which will read live data, freeze frame, just can't use to watch oscillations, square waves, etc. What would you suggest watching on live data?
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