Door Drain Holes and EPDM Weatherstrip: Keeping Water Out of Truck Cabins

Even the best EPDM weatherstrip lets some water in. Rain, car washes, and road spray find their way past the seal. The door has drain holes to let that water out. If the drain holes are blocked, the water pools. It causes rust and mold. For a box truck door seal, a shipping container door weatherstrip, a refrigerated truck and reefer door seal, and a passenger car and commercial vehicle door rubber weatherstrip, drain holes are the partner to the seal.

The door is hollow. It is a metal box. Water enters through the window channels or past the seal. It runs down inside the door. The drain holes at the bottom let it out. If the holes are blocked by dirt, leaves, or mud, the water stays. The door rusts from the inside.

For a passenger car and commercial vehicle door rubber weatherstrip, the drain holes are in the bottom of the door. Clean them every oil change. Poke them with a wire. Run water into the door. Make sure it drains.

For a box truck door seal, the cargo doors may have weep holes. Keep them clear.

For a shipping container door weatherstrip, the container doors have drain holes. Keep them clear.

For a refrigerated truck and reefer door seal, the reefer box has drains. Keep them clear.

The takeaway is that the EPDM weatherstrip keeps most water out. The drain holes handle the rest. Keep both in good condition. A tight seal and clear drains mean a dry vehicle.

References

- Google Scholar: "Door Drain Design and Water Management", SAE International, 2020.

- Google Scholar: "Interior Water Leak Diagnosis in Vehicles", SAE Technical Paper, 2019.

- Google Scholar: "Corrosion from Blocked Drainage Channels", Corrosion Engineering, 2021.