last week i had this truck with a cat motor and a bendix compressor and dry that sprutters air at unload valve on compresssor , i get rebuild kit and then pop off valve on top of compressor starts leaking air bad........call around and no parts but u can plug it.........then i get to work monday truck is broke down 200 miles away.....now get this first i ask driver to un screw the plug on compressor i hear the air clucking away.....first tow guy gets there and works 3 hours says compresser is bad ............. part 2 tomorrow nite
On first read, it sounds as tho your air governor may be the culprit. You ought not plug the safety valve as bad things can happen when you do that, like blown hoses, tubes, and air receivers. Also seals and gaskets in all parts of the system, just too much air pressure you know. Air governors are cheap and really not worth rebuilding in the field. Install a new one with a new gasket. (gasket should be included in box) Make sure you check and adjust the air governor to 120 PSI after installation. I think this may be your problem, but air driers have an unloader or pop-off valve too, which is used to eject moisture from the dryer assembly whenever the air governor kicks out. I have seen them go bad, and freeze up too from ice if the heater element isn't working. If this little valve is bad, your system will have a hard time building air as it's bleeding from the valve. Sounds unlikely as a suspect in your situation. Generally speaking, if the valves in the compressor are bad, you won't build air. If you have a cracked head, you will have plenty of bubbles in the rad, but can also have an air system full of coolant -- which is a very bad thing as it all has to be cleaned out you see. Coolant and seals in air valves hate each other. One last thought I guess. I was about to say that the scrappie running the tow truck is full of beans, but he could be right -- if the unloader valve mechanism is mucked up. This is a rare condition, but I've seen it a couple of times. That would mandate another compressor, but change the air governor with it. Good insurance. Good Luck!
part 2 ... i get the driver to tell 1st tow guy to dont worry about it just leave ill be on the way.... i call a different towing co and get them to go out and all the while im on the way to meet them.....this is what 2nd tow guy found hole in the main air line from dryer to tanks and govonor is bad .....he replaces all .. the gov is built on dryer bendix apid unit .......driver calles me and tells me to turn around hes on way back home....now the purge valve is leaking and i replaced it with a new one and it still leaking..........