Reader Question: I have a 1995 Mercury Villager 3.0 V-6. I have changed the front brake calipers with new ones. The problem is that after bleeding the brake system we still have to go to the floor for brakes to apply.
We changed nothing else and prior to replacing the brake calipers, the brakes worked fine except for the passenger side caliper sticking. Have done brake job on this vehicle before, changing the pads in the front and putting on new rotors.
All we had to do was make sure that we did not disconnect the brake lines, which we did not, and they worked fine until we noticed that the passenger front side caliper was sticking.
Did we bleed the brakes wrong or is something else at fault? One mechanic that we talked to stated that it was possible that the brake master cylinder has gone bad, just cannot buy that.
Any help would be greatly appreciated.
I would open the bleeder screws at each wheel and allow gravity to bleed the system for you, just make sure you keep the master cylinder full of fluid. This should take about 45minutes to an hour to do. This is called gravity bleeding. I would assume you have an air pocket somewhere in the system.
You CAN damage a brake master cylinder by pumping on the brake pedal to bleed the brakes. You force the plunger inside the cylinder farther into the cylinder than it normally travels, and the rust and dirt are in that less traveled area of the cylinder.
You can tear the plunger seal when it hits that rust, thus not allowing a proper seal to build up pressure on the system. I have had to buy a few master cylinders for customers that we damaged. Now we gravity bleed and do not pump the brake pedal anymore.