Hey guys, well before I did the full 2013+ brake upgrade, I had a problem were the passenger side back caliper would actuate much more than the drivers side back caliper and would end up wearing out.
This happened once and I figured the wife just drove with the parking brake semi-engaged or somesuch, so I just changed the pads, made sure everything was bled and everything seemed to work fine.
Almost a year later I have the same issue, the passenger side rear pads are gone (eating the rotor this time) and the drivers side rear is got virtually no wear.
So, I take it as a sign of a bad caliper and just decide to take the plunge and put in an updated version, the complete 2013+ brake system. I installed the brake booster, master cylinder, all new hoses at each corner, all new splash shields, new calipers, new pads, new rotors. I even upgraded to DOT4LV fluid and found I couldn't totally bleed the system, since after 12 liters of brake fluid I STILL had a spongy pedal. The brakes actuated within 1/2" of pedal throw, but the pedal doesn't get firm until way down.
I was sick and tired of spending money on brake fluid, so I used a 20ft 4mm internal diameter silicone hose along with a 7mm clamp to connect to each bleeder screw. I also wrapped the bleeder screws in teflon tape to prevent leaks when bleeding. I ran through the bleed procedure with a Foxwell NT630 scan tool as well as a laptop setup with Forscan and a vLinker cable.
Now, after doing that for 2 hours (which is 300 pedal presses after doing bleeding for a total of 8-9 hours over 4 other attempts for well over 1200 pedal presses) I said screw it and put it all back together and took the car out and drove it. After about a half hour I pull back in the driveway (brakes were fine the whole time, regardless of the spongy pedal) and check the heat of each rotor.
The front two were damn near identical and the rear passenger was almost the same as both fronts. The rear drivers was no-where near the others, like less than half the heat temp.
So, at least I have identified that the rear drivers caliper circuit is the problem.
I jack up that corner, pull the wheel, and run the hose form the caliper to the reservoir again, and proceed to do the service bleed with both the Foxwell and the Forscan methods.
One thing I notice when doing the Foxwell is that if I go in I notice they allow you to actuate solenoids on/off and everything else, but the actualy controls for the left rear (drivers side rear) are MISSING from the scantool. It had the left front, right front, right rear and that is it, no left rear menu options. I have an email into Foxwell at this point to find out what is going on with their tool. I also notice that Forscan can only do the service bleed procedure and does NOT have the ability to actuate each circuit independently, which is a real disappointment.
Now, the only thing I can surmise is that the left rear (drivers side rear) circuit in the ABS unit has a stick valve that is restricting fluid flow to that caliper, as well as not being able to fully bleed that caliper because of said "stuck valve".
That would explain why the original brakes had the other side eat the pads. It also explains the soft pedal and the inability to get air out of the entire system.
So, I guess I am on a search for a replacement ABS unit. I have to see if I can reprogram it via Forscan, or if I need to take it to a Ford dealer to use their IDS system.
If Forscan will reprogram it, then I can get an inexpensive take-off salvage unit and see if that works. If a dealership is going to charge me to program, I might as well buy a brand new ABS unit and have them do the replacement and reprogramming as well as another bleed session.
I just have never heard of an ABS unit failing like this, but I can't see any other sort of explanation for what I have been dealing with. Frustrating is a MAJOR understatement at this point.
If anyone has any input on this, I would be very grateful to hear it.