Air Tank Valves

[Sparky242]

Was looking at the air tank valves on  my Volvo 610, the middle and rear tank have screw in drain valves the front tank(wet tank) has a different looking valve with a cable hanging from it.  wondering why it is different?  Drained the middle and rear tank not much came out ( system had very little air in it) unthreaded the valve out of the front tank and got about a quart of oil out of it, is that normal?  I have owned the truck for about a year and I am trying to learn the systems, I am assuming this needs to be drained a lot more often.  I have only put on about 1000 miles since I bought it    Thanks for any info  Stan

[dlcarsonak]

   The wet tank is the first one to fill from the compressor. That is why there is more liquid in it. The previous owner may have put "Air Dry" in the system to prevent the brakes freezing up in winter, and that is what you drained out.

   If you pull the cable to the side it should release air and liquid from that tank.

   If you drain the wet tank after a short run and there is a lot of liquid, it is possible the rings are bad in the Air Compressor and it needs to be replaced.

[Sparky242]

Thanks for the info I will check it more often

[jenandjon]

  Thanks for the reminder I drained my tanks last summer. I need to do it again. Should do it a couple times a year.

I had oil in my tank also. I called a mechanic buddy of mine because i was afraid the compressor was going out. I have a Detroit. He said for some reason even brand new from the factory Detroit always leaked a little oil in the system.  So unless like a gallon comes out don't worry about it.

[Sparky242]

Thanks for the info I also have a Detroit so maybe it was a normal amount of oil, I will keep  an eye on it for sure.