🛞🔧 Loose S-Cam Shafts Found During Wheel Seal Replacement – Trailer Brake Inspection 🔧🛞 While performing a wheel seal replacement on this trailer, our specialist tech identified loose brake S-cam shafts. This is a critical finding, since S-cams are responsible for applying and releasing the brake shoes evenly inside the drum. 💡 Why loose S-cam shafts are a serious concern: S-cam shafts rotate when air is applied, pushing the brake shoes outward against the drum. When the shafts or bushings