1998 Ford E-350 Q&A
1998 Ford E-350 Question: Brake pedal spongy and slowly goes to floor
The brake pedal is spongy and under pressure goes to the floor. I also notice when I have a helper depress the brake pedal while I look into the brake fluid Reservoir, the fluid boils up. No air, just a backflow of fluid? This is the Vacuum booster model. Dually, rear ABS only. Replaced pads, rotors, rear shoes. - AirFord
Looks like a master cylinder problem. It won't hold pressure and the fluid flows back to the reservoir. If you replace the master cylinder, get the whole brake system flush/bleed out with new brake fluid. You should do this every 2 years or more often if you live in a humid area. Better to bench bleed the cylinder before installation. Zee - ZeeTech
I had the same problem with my E350 rear brakes after changing my brake shoes. I found two things that helped me with the problem. There is a rubber winding hose that travels down to a block on the axle. I straightened that hose as much as possible to free up any air pockets that may have been trapped in it. Secondly, I bled the brake line fitting at the highest point above the axle, where the rubber hose and the steel tube meets. After this, I bled my wheel cylinders and that worked for me. - AAAWoody
after sitting in storage for a month I picked up my 1995 motor home (E-350 chassis)and immediately noticed a difference in the braking. It normally requires barely a touch on the brakes to stop it...