Bendix AD-IP air dryer problem

We do as well.

 

Thanks for the replies on substandard parts and the Wabco turbo-cut off valve.
The first gives me another good reason to support my local vendors.
The second I am unfamiliar with and looked on line. Can someone explain that system or post a sight that does that?
Neither of those is what I was talking about. None of these had the turbo cut off valve that I only found partial diagrams of on line. The compressors I am referring to have a slide valve in the head connected the control line from the governor and I have seen problems with them. One messed up and would not build air at all. The other two (one on an 07 Mack and one on an off road machine with an ISC ) had that assembly stuck and or foundered around in the middle. When the governor sends air to the compressor and the air dryer the compressor should stop pumping air and the dryer should unload. If the compressor does not stop pumping air the unloader is open and will continually leak air. Unhook the line between the compressor and the dryer. No air should be coming from the compressor when it has proper air pressure from the governor line.
Some major companies I worked for rebuilt air dryers on a schedule. They almost always worked fine and were installed by professionals. If one had a problem the company had the liability and expense. Shops may tend to pass on kits for reasons like that. Yes it is possible to save some money doing it yourself but I don't thank I would cheep on the parts. Trouble shoot the problem first.