On our thermostat outing last week I noticed that the PacBrake - which has never given what I would call a "robust" braking effort - was giving zero braking effort even. So today the DW and I went over to see if we could pin it down. It helps to have someone 30 feet north pushing the PacBrake button.
The result was that it needed lubrication. I lube it pretty frequently, I thought, at least. But it took a bit of lube and some manual exercise to get it to work properly. It takes special high-temp lubrication and lots of it frequently. I'm not sure who all might have one of these but it's worth paying attention to. I REALLY like having that PacBrake in the mtns.
I was afraid it would be electrical and had brought over a bunch of stuff to troubleshoot that. Went to the grocery store with the DW so she could shop for cookie-making stuff instead, came home, and settled in to watch the Seahawks play football.
Better than trying to fix electrical issues.
Craig
I had the same experience with my U225. PAC brake told me to lube with their special High Heat Oil once a month. Lubing it is pretty simple but as with most people, once every three months is probably more accurate.
They also told me their new PAC Brake is much more effective than the original and is less than a coach buck ($1000) installed.
Another easy fix for a simple problem is to check the Humphrey valve rubber black seal. If the air solenoid does not work when you flip the switch the rubber seal might be bad. New they are $7.95 from Cleaner Supply.
The easy test is to use 12 volt power to energize the solenoid, if the ram does not move, by air pressure, possibly a bad seal. Unscrew the large nut on the end of the air cylinder and see if it is bad.
We have a U.S. Gear Super-Duty D-Celerator exhaust brake. From what I have read, it is similar in design and concept to the PacBrake. Excerpt from my Operator Instructions: "The Cycle Feature is an exclusive self-maintenance characteristic of the D-Celerator®". If you have sufficient air pressure, and turn the ignition switch to "ON" position, the LED on the control panel will flash for 15 seconds, and then the brake will cycle 2 times. Supposedly helps keep the valve and linkage freed up, especially if it is not used often in normal driving (as is the case with ours). I wait for it before I start the engine - it is easy to hear it "clanking" shut and back open, so I know all is well back there.
D-Celerator Diesel Exhaust Brake (http://www.usgear.cc/dcelerator.htm)