Van Build: Waterproof The Side Trim on a Sprinter/Crafter

You would think that VW, Mercedes, etc. would have covered the basics of waterproofing their vehicles... I'm afraid not.

Written By Freedom Strider

On December 14, 2019

They just love giving DIY van converters more work, don't they?! Something that needs fixing on Sprinter and Crafter vans, is the (usually black) side trim, which is clipped onto the side of the van with clips than have no sealant on them and as a result, overtime they start letting water in (causing even more damage). Since the big shot companies have failed to make their vans watertight, here is what we did to fix it.


Talk about torx!

Behind the wheel arches (front and back) there are tiny little Torx bolts that need to be unbolted in order for you to remove the black trim. 

Scrape away the caked-on dirt and use a T20 Torx head attachment to unscrew them (and don’t get your head trapped). 🤕


Pop goes the Plastic

To remove the trim, go to where the trim meets the wheel arch, and get a flathead screwdriver covered in fabric (so you don’t gauge your metalwork or plastic) and get it between the black trim and the metalwork and tug until you can get your fingers under there.

Then it’s a matter of tugging up hard enough to pop out the plastic clips but not too hard so you break them or the actual trim piece.

You will need to put quite a lot of force into it, and it will feel wrong as though you’re about to break it – this is normal. You will squirm – you have been warned.

Watch out for the indicator lights 💡 These are attached to the plastic side trim! To remove, simply twist and pull out of their housing, and leave them dangling.


When initially doing this, we only removed the black plastic side trim from the middle and rear of the van, but not on the front doors. 

Turns out that there are plastic clips beneath all the plastic side trim, so best just to do it all in one go, otherwise you’ll have to come back and do the front ones at a later date, because they will leak!

The front doors have Torx bolts holding in the side trim as well, on the side of the door.


Spray it all clean

Depending on how old your van is, you might get a mini heart attack to find how much dirt (or even rust) is behind the trim. Do your best to clean, de-rust and protect those areas.

If there is rust, since it is hidden by the plastic, you don’t have to paint it decoratively, just protect it with Hammerite, a rust converter or whatever rust protective primers you have around – something is better than nothing.

Some of the plastic clips might be still stuck in the van, so get a tiny flathead screwdriver, pry between the clip and the metal, find the push point to release on the side, push it in with the screwdriver and then pull them out at an angle.

Please note: your fingers will hurt afterwards. ☝️


Give the clips a soapy bath 🦆

Pull all the clips from the van and the trim out, and clean them in soapy water and wipe the surface that will touch the van, that way the sealant is more likely to do its job.

If your plastic side trim is in need of a clean or repaint, now is the best time to do it, since they are off the van.


Placing all the clips back into their holes on the side trim pieces (preferably the right way around) makes things a whole lot easier when it comes to applying the sealant.

If you broke any clips, they are cheap to buy on eBay.


Sealing the trim watertight

It’s best to do this one trim piece at a time.

Get your neutral cure silicone (this has to be neutral cure; regular silicone releases chemicals that ‘eats’ the metalwork).

Do a small circle on each of the plastic clips until all clips on that trim piece have some, then quickly reattach the trim to the van by lining the clips up to the holes, and essentially press/hit the piece back on. 

Remember to reattach the side indicator bulbs.

Don’t get too aggressive, and remember to rebolt the trim pieces back into place with those Torx bolts. 🤪


quick look

Quick Steps Overview:


  1. Undo torx bolts
  2. Remove side trim
  3. Remove and clean plastic clips
  4. Put clips back into side panel
  5. Add sealant to clips
  6. Reattach side trim