How Improper Truck Washing Can Lead to Undercarriage Corrosion

‘Tis the Season for Truck Washing

With spring officially starting next week, we can look forward to roads that are free of ice and snow. And, like most truck owners, you may be itching to get out the power washer and wash the long, tough winter off your heavy-duty vehicle. After months of driving through road salt, dirt, and debris, it always feels better to drive a polished and shining truck down the road.

But before you go ham with the soap and scrubbers, it's important to note that the way you wash your truck could have a major impact on whether you're actually saving it from corrosion or setting it up to be susceptible to it.

The Way You Wash Your Undercarriage Matters

There's no doubt that a heavy-duty truck is just that – heavy-duty and built tough. But it's a common misconception that spraying water directly through your entire undercarriage is safe. Granted, it's not always easy to get underneath your vehicle and see where you're washing but having a better idea of where not to point the power washer can save you and the vulnerable connections in your undercarriage.

It is true that the calcium and magnesium chloride used to deice roads can be an undercarriage's worst nightmare. The most frequently used deicing chemicals are about 50 percent smaller than traditional road salt, making it easier to fit into tight spaces. If left to stick to your undercarriage, road salt itself can also cause corrosion. So, how do you make sure you're washing your equipment the right way?

• Mind the pressure stream. If the stream of water is too high and is held directly on sealed connections and components, the high pressure can either push out or push past the protective gaskets or material that are in place to prevent corrosion.


• Ensure whoever is washing your truck is avoiding harsh detergents and chemical degreasers that contain acid. If a service provider is the one washing your truck for you, make sure they know how to navigate the water pressure around your electrical system, and don't be afraid to ask about what cleaning agents they use. Washing a truck with cleaning agents that are too harsh can cause cable jackets and air hoses to dry out, and chemical degreasers can actually cause a corrosion reaction when they're put into contact with electrical connections.


• Avoid aiming high-pressure water spray directly at the input, output, pinion, breather, and wheel seals. This will make sure that you don't push contaminants past the lips of the seals.

Corrosion: What to Look For

Now we know not to help corrosion along when you're washing your vehicle, but where do you look to find out if it's happening? While inspecting your undercarriage, pay close attention to the electrical connections and look for:

• Visible oxidation or corroded connections
• Loose connectors or broken wires
• Rust, deformations, and damage throughout the undercarriage
• Any copper wires in your connections that may be showing signs of a powdery green or white substance
• Iron components that have brown or red dust on them
• A lighting failure – this may be the most obvious sign of corrosion in the electrical system

Choosing Electrical Parts that Help Prevent Corrosion

As with most issues that can happen on a truck, the best way to keep your undercarriage corrosion-free is to invest in prevention. In addition to making sure you always wash your truck appropriately, choose lighting and electrical parts and components from brands that take extra measures to keep your system protected. Grote is an example of a brand that keeps corrosion in mind when manufacturing lighting parts and they use solid, spun-brass, and tin-plated terminals for maximum corrosion resistance. Their reflectors and lighting are also fully sealed to prevent premature electrical failures and breakdown.

Phillips Industries also manufactures with electrical protection in mind. Their STA-DRY tubing seals, waterproofs, and insulates connections. Phillips also makes the QCS2 – a non-corrosive 7-way boot to help keep contaminants out.

Check out our full haul of heavy-duty everything and set your electrical system up for success while washing your vehicle and all year long.