The Pacbrake on my truck quit working recently. It didn't go through an intermittent period, it just quit. I thought it may be the solenoid valve so I took the top off of it and it looked very clean so I replaced the top and took the end cover off. I pulled the innards out and everything looked very clean but I cleaned everything with alcohol anyway and re-installed. The brake still didn't work. The only way I could get it to operate was to keep reversing the hoses on the brake side of the valve so I pretty much knew it had to be a valve problem. I called Pacbrake and explained what I had done and they told me there is a little button to push on the solenoid end of the valve. I took a small center-punch and pushed the button--problem solved. I didn't know about this button and thought maybe some of you don't either. It may help you some day. Many thanks to the Pacbrake folks for their assistance.
Phil
Phil