So Ive been a long time lurker on here. Picked up an '89 FLD last year with intentions on making it a dump truck for my bussiness, but plans have changed and now Im considering putting it on the road and doing some flatbed work with it. So onto the problems. sit for roughly 8mo. and when I fired it up the other day to move it, the "foot brake valve"...Im not sure of its exact name...seems to have stuck when I depressed the brakes. I noticed the brake lights were staying on and I have no sound of air, plus the pedal feels light to the touch, like theres no air pressure. What I want to make sure of is that the valve mounted on the firewall is the correct one. There seems to be nothing under the dash, except the rod that the pedal pivots on which depresses a smaller rod through the firewall. Is there a way for me to disconnect one or more of the lines and get the pressure to release the brakes? I know for a fact its the service brakes because the truck has a application guage and whenever the air pressure is up on the truck, the guage is showing approx 90psi.
The other issue is an air leak behind the dash in the hvac controls. It looks like a 5 port manifold and the yellow line is leaking right at the connection. Its enough to drain the tanks within about 5 minmof shutting the truck off. Apparently Im doing something wrong because I cannot get this tiny air line to come off no matter what and its got me stumped.