When to Drive a Truck Through High Water and When Not To (Ask TFLTruck)


Scenes of the historic deluge submerging Houston, with countless cars and trucks submerged in the streets led TFLtruck reader Aaron V.P. to contact us for advice on how to drive a truck in or through high water. It’s a great question, one that thousands of Texas truck drivers are facing this week either in their bid to escape the floodwaters or help rescue their fellow citizens and neighbors. Fortunately, we know where to go for an answer. Nick Cappa, manager of media relations for Ram trucks, responded immediately to Aaron’s questions. (Note: While Nick can’t speak for all truck manufacturers, he can speak to Ram’s capabilities, which is why his responses are limited to Ram trucks.)

To drive in deep water safely follow some simple rules:

  • Always put the truck into 4WD.
  • Never drive in water greater than the approved fording depth (see Owners Manual). For a Ram Power Wagon it’s a 30 inches.
  • Drive very slow and easy since deep water can hide obstacles such as fallen trees, holes, curbs, and loose debris.
  • Drive slowly since higher speeds will cause the water to splash past and over sealed areas. Speed also compromises traction.
  • Trucks are water resistant but not waterproof. Parts such as starters, alternators and AC clutches can be damaged under extreme circumstances and time underwater.
  • If you leave a truck parked in deep water or mud for extended periods of time it would be a good idea to check driveline fluids and grease bearings. Seals in the axles are oil tight but water could find its way over time.
  • Aaron, your concern about warping brake rotors shouldn’t be an issue. Rapid cooling of rotors is only a concern if they are overheated and then quenched in water. In a flood situation where’d be driving slowly, such rates of speed and heat should not make it an issue.
  • If water is moving, even slowly, do not underestimate its power. Driving through it can overpower your tires’ traction, especially in lighter trucks. This is from my own personal experience.

Aaron also suggested posting a link to the Red Cross for TFL readers to contribute to the organization’s efforts in southeastern Texas. We think that’s an excellent idea and thank him for it. Support viaRed Cross donation. TFL crew has already donated to the relief effort.