AIR LEAK

[Michelle]

Hey everyone, 1st time posting on here.have 2015 fl cascadia with an air leak that you can hear while running and for approx 20 secs after shutting it off. It seems like its coming from the center/rear area of the motor.
Replaced the dryer governor
Any input would be much appreciated...

[tree98]

Air it up, turn engine off and key right back on, spray soapy water on the area to find the leak.

[DVT873]

If you just key on but don't start do you hear it? If you do it may be the air line going to the fan hub at the front of the engine. Look for an air line up in that area and follow it back. Usually 1/4".

[Michelle]

(10-23-2022 )DVT873 Wrote:  If you just key on but don't start do you hear it? If you do it may be the air line going to the fan hub at the front of the engine. Look for an air line up in that area and follow it back. Usually 1/4".

No, I cannot hear it. Im currently in the process of trying to get to the unloader valve to replace it. Thank you very much for your input......

[Bengy88]

90 percent of the time on those its the air line that unloads the air compressor.... Its common especially on a dd engine for the line to get brittle and break at the fitting on the compressor head....... And its not the easiest to see

[B O Double V]

Had a very similar issue, happened to be the small hose that ran back to the air compressor from the dryer. It had rubbed on a bolt that held the frame together. The compressor would not stop cycling until fixed.

[Nilao]

I think the 2015 dd15 uses an air solenoid at the rear of the engine to purge the urea lines for 15 to 20 seconds at engine shut down. It could be that line or the valve itself leaking.