The sliding door rail and the sliding door rail cover panel are both prime locations for rainwater ingress. With the rail, the rain water gets behind the foam gasket for the rail end then seeps past the bolt and into your van.
With the sliding door rail cover panel, the fastening clips which hold the panel in the correct position don't seal well at all to the main body panel. The seal is a flimsy thing. Also the clips often crack over time and then fail to pull the panel towards the van body panel, thus compromising the seal.
On another van, I have seen the serious corrosion damage this will cause if both of these things are not fixed.
The fix for the rail involves carefully removing the sliding door cover panel and then cleaning behind the gasket with a paintbrush dipped in meths. Do this several times until no more gunk comes out. Then clean behind the gasket and in front of the gasket thoroughly and make sure it's clean and dry. Once dry, you can then apply a large bead of polyurethane sealant right over the top covering the space between the gasket and the main bodywork and the gasket and the rail itself. This will stop any water getting behind the gasket, past the bolts and into the van.
Also - make sure the rail bolts are actually properly tightened since mine were clearly not tight enough. I don't know the torque needed here. I used a 1/4" ratchet with the correct multi splined bit (DONT use a Torx bit!) and went tight enough to make a dent in my palm. Don't overtighten these bolts.
The fix for the sliding door cover clips is a choice between: 1) adding a small amount of sealant between the existing seal and the main body panel or 2) sealing it from behind inside the van once the cover panel is back on the van. I think its best to fix it using option 1 since this avoids any risk of water sitting against a vulnerable edge. Option 2 would still allow rainwater to sit against an exposed edge (the hole in the main bodywork)
Heres some photos to show the sealant on the bodywork and the rail and a view of the sliding door rail bolts and the cover clip from inside the van cavity. Note that you don't have to be perfect with the neatness of the seal since you won't see this. Just make sure you get a good seal made and make sure you profile it so the rain water flows over the front of the rail and onto the ground instead of creating a small channel.
When taking the cover panel off take your time and it's always best to have a helper here, since doing it on your own is possible - but I don't recommend this if it's your first time.
When you take the cover panel off have a look for any rust on it, and fix this before putting it all back together. I had a bit and removed it with 80g paper and then used 2 coats of 1k epoxy primer and then 2 coats of anti stonechip paint.
With the sliding door rail cover panel, the fastening clips which hold the panel in the correct position don't seal well at all to the main body panel. The seal is a flimsy thing. Also the clips often crack over time and then fail to pull the panel towards the van body panel, thus compromising the seal.
On another van, I have seen the serious corrosion damage this will cause if both of these things are not fixed.
The fix for the rail involves carefully removing the sliding door cover panel and then cleaning behind the gasket with a paintbrush dipped in meths. Do this several times until no more gunk comes out. Then clean behind the gasket and in front of the gasket thoroughly and make sure it's clean and dry. Once dry, you can then apply a large bead of polyurethane sealant right over the top covering the space between the gasket and the main bodywork and the gasket and the rail itself. This will stop any water getting behind the gasket, past the bolts and into the van.
Also - make sure the rail bolts are actually properly tightened since mine were clearly not tight enough. I don't know the torque needed here. I used a 1/4" ratchet with the correct multi splined bit (DONT use a Torx bit!) and went tight enough to make a dent in my palm. Don't overtighten these bolts.
The fix for the sliding door cover clips is a choice between: 1) adding a small amount of sealant between the existing seal and the main body panel or 2) sealing it from behind inside the van once the cover panel is back on the van. I think its best to fix it using option 1 since this avoids any risk of water sitting against a vulnerable edge. Option 2 would still allow rainwater to sit against an exposed edge (the hole in the main bodywork)
Heres some photos to show the sealant on the bodywork and the rail and a view of the sliding door rail bolts and the cover clip from inside the van cavity. Note that you don't have to be perfect with the neatness of the seal since you won't see this. Just make sure you get a good seal made and make sure you profile it so the rain water flows over the front of the rail and onto the ground instead of creating a small channel.
When taking the cover panel off take your time and it's always best to have a helper here, since doing it on your own is possible - but I don't recommend this if it's your first time.
When you take the cover panel off have a look for any rust on it, and fix this before putting it all back together. I had a bit and removed it with 80g paper and then used 2 coats of 1k epoxy primer and then 2 coats of anti stonechip paint.
