1990 f150 4.9. Factory air box has a hose from the valve cover going to the side of the air box to the crankcase breather filter inside. But the hose don't fit the crankcase filter. Is there a adapter I'm not missing to hook it up?

 

No, someone probably put in the wrong breather filter.

 

Maybe..most likely you are missing the plastic elbow that snaps directly on the crankcase filter.



The upper photo shows the small elbow on the end. I believe you can get one in the Help! section at your local automotive parts store. The Ford part number is 388962-S. There is a small retainer clip to hold it in place, Ford Part# D1AZ-9E628-B

 

Thank you! My air box never had a elbow on the breather filter since I owned it. I knew it had to be something.