@shingen I, mot sure when I last drained my moisture trap so I’ve just done it and pretty much nothing came out except air.  There does appear to be rust stains on the “windows” in to it though.

How would I check for leakage of lubricants?  I break it all down in to parts and run it through an ultrasonic cleaner after every prolonged use.  Would that clean up any leakage?

@gilbert There are no pics.  I’m usually applying a wash and I cant stop to take a pic or video or I’ll get tide marks.  I’m also usually panicing and trying to prevent the paint from mixing with the wash or exposing what I painted over.  I could theoretically go and make it happen and take a video but I’d rather not risk damaging my paint work.  Hmmm.  I have paint over the base.  Perhaps there is something I can do.  Let me think on that.

1: I give every paint a good shake (Maybe not a bloody good shake.  Not sure where the line is) to the extent I shake my dropper bottle of water every time I pick it up without thinking.

2: I am currently painting Reichbusters models.  High end board game minis.  Not sure what they are made of.  I gave them all a wash before the primer got to them.  I have painted models of every material.  I can definitely say I’ve had this issue on resin.  Not 100% sure what else I’ve seen it happen to.

3: I add thinner to everything that goes through my airbrush.  With Vallejo primer and varnish its about 50/50.  With Stynylrez its 4-6 drops of thinner and then full the cup with primer.  With the vallejo paints its 6-8 drops paint to 30 drops thinner for a solid coat, but I did try thinning it further for the highlights on these minis.  I’m not very good at thinning my airbrush paints for anything much more than a solid base coat.

4: Not 100% sure which layer is running.  I assume its all of them.  I think I exposed through the layers the other day, but i can’t say for certain right now.