Am I the only one that's had this problem? The factory polyflow tubing running from the PVH valve to the Y connector melted at the frame near the exhaust manifold. Researching why my ESOF wasn't working - I never read that this happened to anyone else. This is on my 06 V10. Not wanting to worry about that happening again I purchased 40" of 3/16" steel brake line. I bough the black clad stuff from Auto Zone hoping it would blend in and not be noticed so easily. I coupled the 3/16" brake line to the factory polyflow tubing by sliding a small piece of heat shrink tubing around the factory polyflow and heating it. I used the 1/4" OD (.177 ID) irrigation tubing - slipped another larger piece of heat shrink tubing over the 1/4" OD irrigation tubing, slid the factory polyflow tubing inside the irrigation tubing, pulled up the larger heat shrink tubing over both pieces and heated it up making an air tight seal. The 1/4" OD irrigation tubing was a tight fit over the 3/16" brake line tubing - again making for an air tight seal. I used a straightened out coat hanger to make my pattern & bent my brake line to match. I had to feed my pre-bent brake line up from underneath the truck up. I used black zip ties to secure the brake line to the factory anchors. That way the metal brake line wont rattle and I can twist the brake line on the anchors to get everything to line up. I wouldn't be able to do this if I taped them like Ford did. Now my lines hold vacuum from the PVH valve connector to both hubs. Unfortunately my ESOF still didn't work so I pulled both hubs and greased them with Mystik Hi-Temp grease. I can hear the hubs lock in when I use a vacuum pump on the vacuum line off the PVH valve. The ESOF still doesn't work. I changed the PVH valve (Dorman 600-402) - ESOF still doesn't work. I have 12.48 Volts to the center pin on the connector - vacuum into the PVH valve but no vacuum out. The transfer case engages & I have 4WD if I manually lock the hubs but I want my ESOF to work like it should. This is driving me NUTS!