I'm back with more of the same. My truck has been in the shop 3 times over the last month - They have replaced the solinoid twice, put all new vac lines and check valves on both wheels, and I still have this problem. My mechanic finally said "Sorry I am out of ideas". When he put the new lines on I drove the truck about 100 miles before the noise came back, so he did something right, it just did not stick.
Anyone here on FTE have any fresh ideas?
1988 F150 Custom 4X4 300 - 6 5 spd trans
1992 F150 XLT 4X4 300 - 6 4 spd trans
1995 F250 XLT 4X4 351 5 spd trans