Hunting Down Leak Under Dashboard, Passenger Side[96 850]

[ToriWhite]

I was mistaken in thinking I had a suspicious rust spot on the windshield.. I was misremembering a small rust spot along the edge of the sunroof.
Today, captive sibling and I took holding a garden hose against the windshield trim. We have reconfirmed, yes, there is a leak.
Unfortunately, the rate at which the leak outputs is so low we were unable to narrow it down between the top, middle, or bottom of the passenger side windshield, or something downstream still. Once the leak area gets 'wet', any decrease/increase in wetness is basically imperceptible; and there's a delay between when the leak is hit and when it makes its way to the spot. I was going at rate of 1 spot test per ~1 minute, but that was too quick to discern with.

As for when/if leak is narrowed down to the windshield liner.. Robert DIY (surprisingly) does not have any videos covering a windshield leak fix. I wonder if its within the scope of something that can be DIY'd responsibly?

Just called my local glass place, and they were really reluctant to offer a 'lift, fix leak/rust, reseat' of the same glass, that in most/all cases they require install something new for liability reasons, and that a new windshield glass is only $500 to freight up!

There's a real chance there's rust causing the seal to break, which would require the windshield to be lifted, sealant removed and rust removed, which I would happily pay a professional to handle for me; but $500 for a brand new glass when mine's still mostly transparent.. looks like I'll have to call around some more!

[abscate]

It will leak from the top. You can splooge a thin bead of RTV under the seal with a helper easing the seal open with a stiff credit card

[BlackBart]

I'm surprised it's not at the bottom of the glass where water can pool. Is it getting behind the rubber at the top?

I've sometimes held a low flowing hose on the lowest spot, for a long time, wait for the leak. If that's not it, start moving slowly higher until you find it. (Old Land Rovers)