That is a classic rust thing with these vans and pretty common. The water is more than likely coming in under your windscreen seal as it rots under there and when the water does get in it runs down the inner bulkhead and pools on the floor rotting it away. very much doubt the water is coming from anywhere else although you could check the pipes to the heater matrix for leaks if you are watercooled.
No point attending to the floor before attending to the leak
Isn't it going to be from the washer bottle, or from running down the A post from a hole in the roof ?
I would remove the paint, treat back to metal and then paint. The paint will probably depend on the treatment you do. If that doesn't work, you still have the remove / replace option
1981 RHD 2.0 Aircooled Leisuredrive project, CU engine
1990 RHD 1.9 Auto Sleeper with DF/DG engine
Agree with 1664, I had/have the same problem, chasing the leak from the windscreen is problematic unless there is an obvious rust bit below the rubber. I suspect when you get a wire brush to this it will show more ventilation. Mine was more on the drivers side which I repaired albeit with fibre glass it did a good job and was complimented with underseal and Hammerite paint. Worth having a look at the footstep cover above and below to see if anything has sneaked in there.
Last edited by TONYT25T25 on 27 Jul 2020, 20:22, edited 1 time in total.
I know if I remove the rust in going to have a hole in the cab floor... I guess the rest of it will work with a standard back to metal / rust proof / respray.
Fibre glass/hammerite might be a good shout over the holes
I've looked all over for the leak... spent a good half hour on my knees. The window seal looks good... It is seems to start half way to up the cab wall from nowhere and has been going on long before I got the van.
If theres a hole there at least the water has somewhere to go.
The window seal may look ok but you need to look under it. There is a lip that collects water , especially in the corner, that is more than likely the culprit. Or the seal might just be leaking like mine was.
Not worth patching the floor until you find the leak.
Last edited by Dazco on 28 Jul 2020, 10:47, edited 1 time in total.
Okay... So I've checked the window and can't see a problem with the seal. There's no water gathered. I'll get a hose out in the morning and see if that penetrates it.... My dash is rusted at the corner there but I thought that would be from condensation run off as there is no rust on the window itself?
I think if I remember correctly when I was tracing the source of my leak in addition to the windscreen, I was a bit suspicious about water collecting behind the Head lights, there is a recess there which collects water and could be a source.