Leaking windows.

[78coromal]

Hey all, ive almost finished restoring a 1978 coromal and replaced all the windows in the process. I was checking for leaks last night and 2 on opposite sides of the van had small drips coming from one top corner. The windows were installed using butyl mastic with a bead of silicone across the top for "justin". While trying to find the leaks they randomly stopped at the same time and no evidence of further leaks this morning after 30mm more rain has fallen. No leaks in last rain event of about the same size and they have both been opened in the interim. Any ideas? 

[pisces51]

G'day 78coromal, and welcome to the forum!

If you read through the following tutorial Step-by-Step Wind-Out Window Repair on the CaravansPlus website, you'll see in the first diagram the little parts at the top of the window known as the "end plugs". It is possible that water is running along the top of the window 'hinge' section, and when it gets to the end, the water finds its way back into the end plug section, and then into the van.

Check the condition of your end plugs, and replace or repair if necessary.

On a 1992 Windsor van I owned for a short period, I had a similar problem to you, and I found that I could solve the problem by coating some silicone over the very end of the plugs to stop any water wanting to backtrack into that part of the window.

When you say the leaks "randomly stopped", are you absolutely sure the water ingress actually stopped at that position, as opposed to the water finding another path into the van?? For example, water may drip for a period of time until the surrounding timber is saturated, and then the water flows further down the saturated timber (ie. the path of least resistance), rather than showing as an actual 'drip'. You may not readily see the water continuing to flow down the timber, especially if it is flowing into the wall cavity. It's often not until the bottom timbers rot away in these old vans that people realise there must have been a fair bit of leaking into the van over the many years.

cheers,
Al.

[78coromal]

Thanks, im pretty sure the leak stopped as it was running down the plastic windowsill moulding after coming through the window. No telltale "wet dog" smell to indicate bulk water ingress thankfully and one small wet patch on internal wall where the water was running down. Maybe not strictly random stopping as i was opening and closing the windows etc looking for the problem. Funny you mention end plugs, i was looking last night and noticed that the leaking corners had a lot less silicone on the end plug than the non leaking ones - from factory. One even had a visible gap between the rubber and frame. Ill put some silicone on them this arvo now its dry and see how it goes. Van is also parked on a slope with the back down which ive heard can exacerbate window leaks.