When is the last time you filled this tank before installing the new GW box?  Could be a hole in the tank or in the fill hose. I don’t think the kinked vent tube is causing this.  It's best to replace the funky old fill hose along with the box. Get the proper one from GW or any RV store since the tank nipple is threaded to screw it on, and then the clamp can seal it. Any other hose will  leak at the tank, even when clamped: http://www.gowesty.com/product-details.php?v=&id=20100

They should sell this hose with the box as a pair IMHO.

Stuart

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of Jared Planter
Sent: Thursday, June 15, 2017 2:26 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Filling the water tank

Hey guys

I had a shop add the new utility boxes from GoWesty and replace the plumbing on our tank. Everything works great except when we fill the tank, water leaks out of the drain channel on either side of the van (depending which way the van is leaning). The channel runs under the flooring at the base of the rear bench. We were told that was normal but we noticed on the inside of the fill port lid it says to shut off the water at the first sign of water at the weep hole on the fill port. Water never comes out of that weep hole, it only ever drains out of one side or the other if the van. Now that we're in a damp climate the water isn't drying and we're starting to smell mildew. We're trying a dehumidifier to dry things up but we want this to work properly in the future. Any thoughts? She's an 87 westy.

Thanks!

Jared