Air dryer purging oil

[88atlas07]

So to add to the saga of things that need to get addressed, I noticed the air dryer purging some oil. Its not a puddle or anything, but the wet tank has a small leak from the drain valve and the tank is getting oily around it. There's also a patch of oily grass under where the air dryer purges. Truck is a '98 3116 with 16k miles. I assume oil is getting past the rings of the compressor, I'm guessing either a vacuum from an air restriction is drawing the oil through, or worst case a worn compressor. Anyone else ever come across this? Just spent a small fortune on highway gears, fox shocks, and cab air bags...really don't want to fork out for a new compressor

 

[Ronmar]

Well unfortunately it is probably a worn compressor. The comp pulls some vacume every time the piston goes down to draw in air. One thing y0u can check is the inlet airline up to the main air pipe is not kinked/crushed and your air filter is clear so it pulls as little vacuum as possible...

 

[snowtrac nome]

It is normal for air dryers to purge some oil the more time on it the more oil you will purge. change the cartrage you will be good to go. There is always going to be a little oil getting by that's why compressors for breathing air are dry or have a complex filtration system on them.

 

[Scrounger]

It is normal for air dryers to purge some oil the more time on it the more oil you will purge. change the cartrage you will be good to go. There is always going to be a little oil getting by that's why compressors for breathing air are dry or have a complex filtration system on them.

As already posted, it is normal for oil to purge with the air. The systems are designed for the dryer to be as far away from the compressor as possible so the oil vapor can condense and be filtered. Over time the filter cartridge becomes saturated with oil. That is one of the reasons for regular dryer servicing.

 

[Ronmar]

Some oil yes, but it sounds like he is getting a lot of oil... have you disassembled the dryer yet?

The dryer also needs to purge regularly to stay clean and shed water and emulsified oil. It purges each time the compressor gets the wet tank to set pressure and the governor unloads the compressor. If you have leakage the compressor runs longer and purges less. If it runs too long it builds/coalesces enough water(and oil) in the media that it starts pulling it into the wet tank.

 

[88atlas07]

Good to hear that there's a possibility its normal. I haven't taken apart the air dryer yet, but I'd imagine its well overdue a cleaning/replacement. I've had the truck for 500 miles since picking up at the auction so still noticing odds and ends. Unfamiliar with diesels so its a learning curve