I'm a new member and I have a 2000 Expedition that I've owned since new. It leaks about 1/4" of brake fluid per week (as measured in the master cylinder) from an area near the HCU. I initially thought it was the master cylinder that was leaking but I replaced it with no improvement. The brakes work fine otherwise with no fading etc.

Any advice here? If I replace the HCU with a junkyard part, is special equipment required to bleed the HCU? Is it possible that there is something else that could be leaking in that vicinity?

Thanks for your help.

 

Did you check that your brake lines are all tight?

Is it actually leaking from the ESP Hydraulic Unit?

I would spend some time wiping everything down with a rag, and then get someone to press and hold the brake pedal, to find the leak before you bother replacing the ESP.

And yes, if you replace the ESP with a junkyard unit then I would recommend having it bled while the valves are cycled. You need a special computer to do this.

Or you could buy a new service part - these come fully bled (the secondary circuit that is behind the valves) so you should be able to do a normal bleed.

 

I finally was able to get a good look at the location of the leak while I had my son hold the brake pedal down. Unfortunately, I could see nothing as it appears that the leak is beneath the HCU. Is the only option at this point to replace the HCU? If so, and I use a junkyard part, is the Ford dealer the only one that would have the computer to cycle the valves. I hate dealers with a passion and would go there only as a last resort. Thanks

 

Some independent shops that do brake work should have the computer.