2012 Ram 3500 6.7L Cummins


Brake pedal goes to the floor and slow to return. When bleeding brakes, flow is very low. Recently changed out front pads and bled the system using vacuum. The pedal went about half way down before the work and was a bit spongy. I tried to bleed the system again but was only getting a trickle of fluid at 15 psi vacuum. I’m trying to figure out if the problem is with the hydrobooster, master cylinder, or ABS manifold

After reading about your issue I am quickly reminded of a time in the past when the problem was a kink in the brake hose. This happened because the hose was twisted when the brake caliper was put back on after new pads and rotors. It happens, take a look at the hoses as they may just be damaged/worn.

Brake pedal feels spongy or has excessive travel

  1. Check the brake fluid level and condition. If the fluid is contaminated or has not been flushed every two years, clean the master cylinder reservoir, and bleed and flush the brakes using fresh brake fluid that meets the manufacturer’s recommended standards.
  2. Check for a weak or damaged flexible brake hydraulic hose. Replace the hose and flush the brake system.
  3. If the brake system uses drum brakes front or rear, check the brake adjustment. Inspect for seized adjusters and clean or replace, then properly adjust.

Source: https://www.freeautomechanic.com/brakes.html