Why would there be signs of moisture in Tuflo 700 compressor?

Dismantled the top end of the Tuflo 700 compressor on my CAT 3408 because the unloader valve in the body was broken and pressure was going to 145 psi. There are signs of rust on the discharge valve spring in the head on one side. What do you guys think, is it simply moisture or something more serious like coolant getting in there? The spring is quite rusty but the other one is not. I’ve cleaned the head, it had a fair bit of carbon before I cleaned it.

 

Water is a byproduct of compressing air. This is why you need a dryer, to remove the moisture created by compressing the air.

Was there evidence of coolant in the wet tank? I would say if it was coolant the parts would be rust free.

Replace the broken parts and move on.

 

That’s what I’m doing, putting a cylinder head maintenance kit in it which includes unloader valves. Just curious as to why one discharge valve spring looks rusty and the other one doesn’t. Its chamber looks rusty as well.

 

Not to hijack your thread but, a while back I believe you had a mysterious air leak .
Did you ever find it?

 

No! One of life’s mysteries. I used a special sensitive foam leak detector and sprayed everywhere. Isolated several systems, but it wasn’t enough to find it. Airbags stayed up so it wasn’t them,