Here is what I found when I removed my UIM. There is 'cap' (red circle).



But when I tried to test the solenoid, it wouldn't hold any pressure. It kept leaking from the cap. I'm pretty sure it's not supposed to do that. I capped it properly and it holds lots of pressure now.

The reason I ask to make sure and because it looks like there is the same cap in this diagram.

http://fd3s.net/vacuum_hose_replacement.html

Sooo many millions of little questions!

 

When there is no voltage supplied, the solenoid should flow from the nipple with the hose attached (see pic) to the nipple under the dust cap. The unconnected nipple should not leak when 0v is applied.

With 12v applied, the solenoid should flow from the hose to the unconnected nipple.

So it sounds like yours is behaving properly.

Dave

 

Yep, that cap is basically an air filter - many of the solenoids switch between vacuum or boost to atmospheric pressure.

Dale