Replaced LH master cylinder on Left side with one Vans shipped free. [ After initial installation, when I pumped this brake, bubbles in the line would immediately appear and the brake would get soft...all others were OK. No leaks anywhere...so appeared to be ingesting air.] Drained per gravity the brake fluid, then disconnected the cylinder. Please no drips. Transferred original elbow fittings, and installed new cylinder. After refilling -- No leaks, No bubbles, and stays firm. Hooray! It was a defective cylinder (probably at shaft seal) sucking in air on back strokes. Rare, but another builder had reported same issue in VAF forums a few years ago.
Left master cyl is slightly darker finish vs original and mate on right side |