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Discussion Starter #1
Hello fellow owners,

This issue have been blowing my mind. I started to feel brake pedal softness, and my mechanic replaced master cylinder. It looked like issue was fixed but after some time pedal became soft again. he replaced master cylinder again but issue did not disappear. it looks like air is sucking in from some place. I checked brake lines and changed all the houses and rebuild calipers with new rings. Bleaded system again and had the same issue, brake fluid don't disappear but after some time (20 miles) pedal is soft. I replaced DSc unit and still have the same issue. The interesting part is if I start INPA brake bleeding everything looks good except rear left. Pre bleed starts and it is ok, once I start cycling DSC module to take the air out it brings more air to the system. So I figured this is the issue but where air can come in to only 1 Rear left Line?
 

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Might be leaking at the ABS block. Did you check the upstream hard lines? I have a leak at one of the hard lines after putting in a rebuilt ABS/DSC unit.
 

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What would be the best way to check for a leak? From just looking at them they look good, no brake fluid is leaking, and lines look pretty good.
 

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Well I eventually had a puddle but the way I found which line it was I cut strips of paper towel and put it in between each line. Then pumped the breaks. After 3 or so pumps checked the strips to see which had absorbed fluid. You can see mine coming out at the threads bc it鈥檚 not sealing.

If air only comes into the system during the ABS portion of the brake bleed (assuming your are using INPA?). Then it鈥檚 pretty safe to say it鈥檚 leaking air in the module somewhere
 
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