Winter prep checklist for semi trucks and trailers
The first hard freeze is when a truck shows you what you skipped in the fall. A weak battery, water in the air tanks, fuel starting to gel. This winter prep checklist for semi trucks and trailers walks the systems cold weather hits first, so a Lehigh Valley winter does not catch you on the shoulder.
Batteries and charging
Cold cuts a battery's cranking power, and a battery that turned over fine in October can quit at ten degrees. A heavy truck runs more than one battery, and they age as a set, so test the batteries and the charging system before the freeze. Our note on battery and electrical service covers what we check and why grounds matter as much as the batteries.
Cooling system and coolant
Coolant does two jobs in winter. It carries heat away, and it keeps from freezing. Test the freeze point and the strength, because a weak mix can freeze and crack a block. Check the hoses, the cap, and the water pump while you are there. The same cooling system that overheats in July is the one that fails on a cold morning.
Air system and the dryer
This is the one that strands trucks on cold mornings. Water collects in the air tanks, and when it freezes it locks up valves and lines, so the brakes drag or will not release. Drain the tanks, service the air dryer, and fix any moisture problem before the cold sets in. It is the same upkeep behind most air brake problems.
Fuel: gelling and water
Diesel has wax in it that thickens in the cold and can gel, blocking the filter and stalling the engine. Run a winter blend or an anti-gel additive rated for your temperatures, and drain the water separator, because trapped water freezes and stops fuel cold. Watch for the hard starts and power loss that fuel trouble brings. Your DEF matters too: it freezes at about 12 degrees, and the truck's emissions system relies on a heated tank and lines to keep it flowing.
Tires and traction
Cold air drops tire pressure, about one psi for every ten degrees, so a tire that was right in the fall is low by winter. Check cold pressures often and set them to your load. Tread matters more on snow, and the legal floor under 49 CFR 393.75 is 4/32 of an inch on steer tires and 2/32 elsewhere. Carry chains where the law requires them. Our note on tire pressure covers setting it right.
The cab, lights, and wipers
Short winter days mean more night driving. Make sure the heater and defroster work, the washer fluid is rated for the cold, the wiper blades are good, and every light is clear of ice and road salt so other drivers can see you.
Make it one scheduled winter prep stop
All of this fits into a single fall service. We run a winter prep as part of your preventive maintenance, test what the cold will find, and tell you the price first. We are at 9883 Old US Highway 22 in Breinigsville, open 24 hours Monday through Friday and Saturday until midnight. You can see the work on our truck maintenance services page.
FAQ
How do I keep my diesel from gelling in winter?
Run a winter-blend fuel or an anti-gel additive rated for your temperatures, and drain the water separator so trapped water cannot freeze and block the fuel.
Why do my air brakes freeze up?
Water in the air tanks freezes and locks the valves and lines. Drain the tanks and service the air dryer before the cold to prevent it.
What tire pressure should I run in winter?
Set it to your load and check it cold and often. Pressure drops about one psi for every ten degrees, so tires that were right in the fall go low as the temperature falls.
When should I winterize my truck?
Before the first hard freeze, in the fall. Testing the battery, coolant, air system, and fuel then is cheaper than a no-start or a frozen line later.
Before the cold sets in, bring your truck to Royal Truck Repair near Allentown, call (610) 841-2521, and we will get it ready for winter in one stop.