Muffler Bearing
Senior Member
Hopefully this will be news to at least one person on this forum. But this is the most valuable tool you can get for diagnosing air systems on a heavy truck or some old loaders and such. To use it you remove the 1" fitting on the air compressor outlet and screw this adapter into the metal flex line running to the air dryer.
Now with the air tanks at less than 90 psi, run the engine and hook shop air (over 120 psi) to the adapter, listen to the air puffing out of the compressor, you shouldn't be able to stop the air with your thumb, if you can, your unloader is sticking halfway open. When the gauge hits 120 the compressor should stop and the purge valve should pop. You have just tested your unloader, governor and purge valve.
Next stop engine, pull shop air off the adapter and a quick (5 sec) puff of air will shoot out of the line then stop. This is testing your check valve.
Now hook shop air up again, spray soapy water over the fabric line between the metal flex line and the dryer. If the line becomes covered in foam, think of each little bubble as a penny you are loosing in fuel and compressor wear. Also check the whole truck for air leaks, then chock wheels release brakes and check everything again.
This little adapter is great for all these things plus when you want to get a truck out of the shop, but don't want to run the truck for long in the shop building air, just throw this on and fill it with shop air.
This tool is available from a supply shop for $15 in parts. Or from Snap On for $287, and if you buy it today, next month they will have an updated version making your's obsolete.
DISCLAIMER: I'm sure there is some air compressor set up out there that defies all these rules, I haven't seen it, but that doesn't mean I speak for everything every built.
Now with the air tanks at less than 90 psi, run the engine and hook shop air (over 120 psi) to the adapter, listen to the air puffing out of the compressor, you shouldn't be able to stop the air with your thumb, if you can, your unloader is sticking halfway open. When the gauge hits 120 the compressor should stop and the purge valve should pop. You have just tested your unloader, governor and purge valve.
Next stop engine, pull shop air off the adapter and a quick (5 sec) puff of air will shoot out of the line then stop. This is testing your check valve.
Now hook shop air up again, spray soapy water over the fabric line between the metal flex line and the dryer. If the line becomes covered in foam, think of each little bubble as a penny you are loosing in fuel and compressor wear. Also check the whole truck for air leaks, then chock wheels release brakes and check everything again.
This little adapter is great for all these things plus when you want to get a truck out of the shop, but don't want to run the truck for long in the shop building air, just throw this on and fill it with shop air.
This tool is available from a supply shop for $15 in parts. Or from Snap On for $287, and if you buy it today, next month they will have an updated version making your's obsolete.
DISCLAIMER: I'm sure there is some air compressor set up out there that defies all these rules, I haven't seen it, but that doesn't mean I speak for everything every built.
