There are several problems. Your caliper could be stuck and that is a problem. You probably have a rubber brake hose that is clogged up internally and restricting the flow of fluid, a second problem.
The internal rubber hose can form flaps which close off the flow of fluid. You only have pressure in 1 direction so it is easier to have a stuck caliper because the fluid will trap in the caliper and refuse to return to the Master cylinder.
But this must really be blocked or the safety valve has shut off the diagonal lockout for the ABS. For safety when fluid pressure is lost, a valve shifts and tries to keep a front and a rear brake diagonally supplied with fluid.
What you need to try before giving up on the current project is bleed your brakes starting from the longest rear line and work your way forward with the last line being the shortest.
You may discover that you now have fluid bleeding from the problem caliper. If so, part of the problem was the safety valve killed the fluid flow. You still have a bad rubber line, and possibly a stuck caliper, but now you may have fluid flow.
If I were you, I would buy a rubber brake line and change it before bleeding the system. Then you can see if the caliper is working or not. Rubber lines are cheap compared to most parts.
By bleeding the lines as I recommend, you stand a chance of centering the safety valve and solving part of your problems. If a rear line diagonal to the problem front caliper is also dry, then the safety valve was tripped.
With the rubber brake line removed, you should be able to compress the problem caliper with ease; if not, it is stuck and should be replaced.
At this point, I should mention the ABS box. Pressure coming from the box can be measured as well as Master cylinder pressure going to the box. Hydraulic gauges would be necessary. It would be the final explanation to your problems should the easier solutions fail. Testing price versus component price should be considered.
You will restore fluid flow and be able to test your stuck caliper using what I gave you.
Jun 02, 2013 |
1998 Mercury Mystique