Failed Hydraulic Brake Booster
I had one fail on a 2000 Ram 2500 diesel. It leaked inside the cab via the 'push rod' as well as under the hood. The one on my 2003 Ram 2500 diesel failed as well. Puddled about a 12" circle of fluid on my garage floor, but had very minimal leakage in the cab. The master cylinder does not require opening the brake fluid lines to remove the booster - but the master cylinder must be disconnected from it. BTW, my son has a 2002 Chev. Duramax. Has the exact same sydraulic booster - it failed as well. We are 3 for 3 at my house.