Replacing Air compressor Lines

Yea I found it at freightliner in Greensboro and they gave it to me for $8 for straight coolant. Matter of fact the pre mixed was almost $12 but I found it for 10$ at a small place in the town I live in

 

Operation was a success. I purchased some crows feet ratchet set.... and was able to get behind the compressor to unscrew the lines. I didn’t flush it as it was done back in October..... I took one off Monday and replaced. Got frustrated with the 2nd one because I didn’t realize I needed a 7/8 and not a 3/4. Found the 7/8 crows foot today and had the line off 20 minutes later!!! Now I just need some freight!!!

 

Ok I’ve replaced 2 of 3. The last one seems to be under pressure. I’ve taken the top off the coolant reservoir to relieve some pressure but it didn’t work. Anyone know how to take the pressure off this line.....

 

No in that picture I have a crows feet wrench on it, I don't have any problem getting to it.......

It is a coolant hose as you can see in the middle of the picture there is coolant that has dried from leaking from that line. I drained the air tanks which I thought would relieve the pressure. I let it cool down overnight so maybe it will help. Ill see this morning.....

 

It runs to the side of the engine block. And yes I think its under pressure. I can tighten it, then I can loosen it back to where it was before I tightened it but can't get it any more loose because of the pressure. Its definitely a coolant line. I already have the hose to the air intake off in that picture....

 

@Hulld any ideas?