Brutal Cold Incoming: Protect Your Fleet This Weekend!

By Richard Kemner, RDK Truck Sales | January 2026 | Cold Weather Fleet Maintenance

If you’re running routes anywhere from the Midwest to the Northeast and Mid-Atlantic
this weekend, you already know what’s coming. We’re looking at temperatures dropping
well below freezing—some areas dipping below zero—with ice storms, snow, and
freezing sleet making things even more challenging.

After 40+ years in this industry, I’ve seen plenty of cold snaps. But today’s trucks and
equipment require a different game plan than they did 20 years ago. Here’s what you
need to know to keep your fleet moving.

The DEF Problem: Your Biggest Cold Weather Enemy
Diesel Exhaust Fluid freezes at 12°F (-11°C). That’s not “below zero” cold—that’s a
regular winter night in half the country this weekend.

What happens when DEF freezes: Your truck goes into derate mode (reduced power).
In severe cases, the engine won’t start at all. The DEF tank and lines can crack if
completely frozen.

What to do: Keep trucks in heated buildings overnight whenever possible. If outdoor
parking is your only option, use DEF tank heaters. Run the engine periodically to keep
the system warm. Never add additives to DEF—it voids warranties and damages the
system. Keep DEF tanks at least half full; less fluid freezes faster.

DPF and Aftertreatment Systems
The Diesel Particulate Filter and SCR systems on modern trucks hate cold weather.
Regen cycles take longer, sensors get sluggish, and the whole system works overtime.

Watch for: Extended regen times tying up trucks. Warning lights from cold sensors
giving false readings. Blocked regens if trucks are doing short runs and shutting down
before completing cycles.

What to do: Let trucks fully complete regen cycles before shutting down—even if it
means idling an extra 20 minutes. Don’t ignore warning lights; cold weather amplifies
small issues into big problems. If a truck has been sitting in extreme cold, let it idle and
warm up before hitting the road.

Hydraulic Systems: Your Packer’s Worst Nightmare
This is where I see crews get into real trouble. Hydraulic fluid thickens dramatically in
cold weather. What flows like water at 70°F moves like honey at 10°F—and barely
moves at all below zero.

The problems you’ll see: Slow or jerky packer operation. Cylinders that won’t fully
extend or retract. Increased strain on pumps (leading to premature failure). Seals that
crack and start leaking.

What to do: Warm up the hydraulic system before running full cycles—operate the
packer slowly through several partial cycles first. Check hydraulic fluid levels; cold
weather reveals low fluid faster. Inspect all hoses and fittings for cracks before heading
out. Consider switching to a lower-viscosity hydraulic fluid for winter operations if you
haven’t already.

Packing Frozen Trash: Physics Works Against You
Here’s something newer operators don’t always think about: frozen garbage doesn’t
compact like regular garbage. When trash is frozen solid, your packer is essentially
trying to crush ice blocks. This puts tremendous strain on the packer, the hydraulics,
and the truck’s PTO system.

What to do: Don’t force it—if the packer is struggling, back off. Expect reduced
payload; frozen material takes up more space. Run more frequent trips rather than
trying to crush frozen loads into one haul. Inspect packer blades and components for
damage after running frozen loads.

Quick Pre-Trip Checklist for Extreme Cold
Before your drivers head out this weekend:

1. Check all fluid levels – engine oil, coolant, hydraulic fluid, DEF
2. Inspect batteries – cold weather kills weak batteries; test them now
3. Look at air dryers and tanks – moisture freezes and locks up brakes
4. Test all lights – shorter days mean more time running in the dark
5. Verify tire pressure – cold drops PSI; check and adjust
6. Confirm heaters work – cab heaters and DEF tank heaters
7. Check wipers and washer fluid – use winter-rated fluid only

The Bottom Line
Modern trucks give us better fuel economy, cleaner emissions, and more power than
ever. But they also demand more attention in extreme weather. The crews that take 30
extra minutes to prep their equipment this weekend are the ones who won’t be stuck on
the side of the road calling for a tow.

Stay safe out there. If you need parts, service support, or just want to talk through what
you’re seeing in the field, give us a call. That’s what we’re here for.
RDK Truck Sales has been serving the refuse industry since 1997. We’re an
independent dealer representing Battle Motors, Pac-Mac, New Way, Labrie, and all
major chassis manufacturers. Sales, service, parts, and leasing—nationwide.

Like our cold weather fleet maintenance blog? Check out some of our other material.

This DPF and DEF system maintenance guide covers best practices, common mistakes, and how to avoid costly repairs.

Brought to you by Richard Kemner | RDK Truck Sales

THE 5 MOST COSTLY MISTAKES

1. Putting diesel fuel in the DEF tank → $8,000 – $15,000 system replacement 2. Using non-dedicated funnels or containers → Permanent catalyst poisoning ($3,000 – $5,000) 3. Using old, heat-damaged, or diluted DEF → Injector failure, crystalline deposits ($1,500 – $3,000) 4. Interrupting DPF regeneration cycles → Excessive soot loading, forced regen, potential DPF damage ($2,000 – $8,000) 5. Ignoring warning lights and fault codes → Small problems become complete system failures

Quick Reference: Do’s and Don’ts

DO THIS	NEVER DO THIS
Use only API-certified DEF	Put any other fluid in DEF tank
Use dedicated blue DEF equipment only	Use funnels/containers that held other fluids
Store DEF in cool location (50-77°F ideal)	Store DEF in direct sunlight or above 86°F
Clean filler area before opening DEF cap	Leave DEF cap off or fill in dusty conditions
Allow DPF regeneration to complete	Shut off engine during active regeneration
Use CK-4 or FA-4 low-ash engine oil	Use high-ash oil (accelerates DPF clogging)
Address warning lights immediately	Ignore fault codes or “wait and see”

Section 1: How to Fill a DEF Tank Properly

⚠ WHAT GOES WRONG: • Cross-contamination: Using equipment that touched fuel or oil introduces contaminants that poison the SCR catalyst permanently • Dirt and debris: Particles enter through dirty fill areas, clogging the DEF filter and pump • Misfueling: Even a small amount of diesel in the DEF tank destroys the entire SCR system

Required: Clean Filling Procedure

1. Clean the area around the DEF cap with a lint-free cloth before opening
2. Use only dedicated DEF equipment (blue funnels, containers, nozzles) – never equipment that held other fluids
3. Verify DEF is API-certified and check the date – don’t use expired product
4. Fill slowly to prevent splashing – do not overfill
5. Replace cap immediately after filling – never leave it open
6. Clean up any spills with water immediately (DEF crystallizes on surfaces)

Equipment Requirements

• Containers: Stainless steel or HDPE plastic only – dedicated to DEF
• Funnels: Blue color-coded, never used for anything else
• Storage: Keep filling equipment covered and clean between uses
• Incompatible materials: Copper, brass, zinc, galvanized metal, aluminum, carbon steel – contact with these contaminates DEF

Section 2: How to Store DEF Properly for to Reduce Degradation

⚠ WHAT GOES WRONG: • Heat degradation: DEF stored above 86°F breaks down, forms crystalline deposits in the injector and catalyst • Wrong concentration: DIY mixing or water dilution causes improper NOx conversion, triggering fault codes and derating • Metal contamination: Trace metals from improper containers permanently poison the catalyst – cannot be reversed

DEF Specification Requirements

Only use DEF that is API-certified and meets ISO 22241 standards:

Parameter	Requirement
Urea Concentration	32.5% ± 0.7% (CRITICAL)
Water Quality	Deionized/demineralized only
Metals (Ca, Fe, Cu, Zn)	< 0.5 ppm total
Phosphates	< 0.5 ppm (trace amounts kill catalyst)

Storage Temperature Impact

Temperature	Shelf Life	Action
50-77°F (10-25°C)	24+ months	IDEAL
77-86°F (25-30°C)	~12 months	Acceptable
86-95°F (30-35°C)	~6 months	Use quickly
Above 95°F (35°C)	Rapid breakdown	DO NOT USE

Storage Best Practices

• Store indoors in a cool, dry, well-ventilated area away from direct sunlight
• Keep containers sealed – ammonia evaporates from exposed DEF
• Practice FIFO (First In, First Out) – mark containers with purchase dates
• Never mix DEF from different suppliers or batches

Section 3: Proper DPF Maintenance Required

⚠ WHAT GOES WRONG: • Interrupted regeneration: Shutting off the engine during active regen prevents soot burnoff, leading to excessive loading and forced parked regen • Excessive idling: Low exhaust temps produce soot but can’t burn it off – rapid DPF loading • Wrong engine oil: High-ash oils leave incombustible deposits that regeneration cannot remove • Ignored warning lights: Continued operation with high soot loading can cause thermal damage to the DPF substrate

Understanding Regeneration

The DPF collects soot and must periodically burn it off. There are three types of regeneration:

Type	When It Happens	What To Do
Passive	Automatically during highway driving (high exhaust temps)	No action needed – happens naturally
Active	ECM injects extra fuel when passive isn’t enough (light may illuminate)	Keep driving until complete – don’t shut off
Parked/Forced	Required when DPF is severely loaded	Must perform immediately to prevent damage

Operational Best Practices

1. Allow regeneration to complete: When the DPF indicator shows active regen, maintain steady driving (if safe) until it finishes
2. Schedule highway time: Vehicles with mostly short-trip, stop-and-go operation need periodic highway driving for passive regen
3. Minimize idle time: Excessive idling produces soot without the heat to burn it off – use APU when stationary
4. Use correct engine oil: CK-4 or FA-4 rated low-ash oils ONLY – high-ash oils clog the DPF with incombustible ash Read this article for more information.
5. Fix engine problems promptly: Oil leaks, bad injectors, turbo issues dump extra soot or oil into the DPF
6. Use ULSD fuel only: High-sulfur fuel damages the DPF and DOC catalyst

Warning Signs of DPF Problems

• DPF warning light or check engine light illuminated
• Reduced engine power or limp mode
• Frequent regeneration attempts
• Increased fuel consumption
• If any of these occur – address immediately to prevent costly damage

Service Intervals

Service	Interval
Back pressure monitoring	Every PM / continuous
DPF inspection	Annually or every 100,000 miles
Professional ash cleaning	150,000 – 300,000 miles (varies by duty cycle)

Section 4: How Small Problems Become Big Repairs

Poor DEF quality and improper DPF maintenance create a cascade of failures. Understanding this chain helps explain why prevention is so important.

Initial Problem	What Fails Next	Final Cost
Contaminated DEF	DEF pump → Injector → SCR catalyst → NOx sensors	$3,000 – $8,000
Fuel in DEF tank	Destroys entire SCR system simultaneously	$8,000 – $15,000+
Heat-degraded DEF	Crystalline deposits → Injector clog → Poor dosing → Catalyst deposits	$1,500 – $5,000
Ignored regen cycles	Excessive soot → Forced regen → Thermal damage to DPF	$2,000 – $8,000
Wrong engine oil	Ash buildup → Reduced DPF capacity → Premature cleaning/replacement	$500 – $3,000

The Bottom Line

PREVENTION COST Quality DEF: ~$3/gallon Dedicated equipment: ~$50 one-time Proper storage: Minimal Training: Time only

FAILURE COST DEF injector: $800 – $1,500 DEF pump: $1,000 – $2,000 SCR catalyst: $2,000 – $5,000 DPF replacement: $3,000 – $8,000 + Downtime

Section 5: Maintenance Checklists

Daily (Driver Responsibility)

• Check DEF level – top off using clean filling procedures
• Monitor dashboard for DPF or DEF warning lights
• Allow regeneration cycles to complete – don’t shut off during active regen
• Report any unusual exhaust smoke or odors

Weekly (Shop/Fleet Manager)

• Verify DEF inventory is properly stored (cool, sealed, in date)
• Inspect DEF filling equipment for cleanliness
• Review any logged fault codes across fleet

Each PM Service

• Check exhaust back pressure readings
• Inspect DEF tank cap and seal condition
• Inspect DEF lines and connections for crystalline deposits
• Check for DEF leaks
• Review and document any stored fault codes
• Verify correct engine oil is being used (CK-4/FA-4)

Annual

• Professional DPF inspection – evaluate cleaning need
• DEF system component inspection
• NOx sensor testing
• Audit DEF storage and handling procedures
• Driver/technician refresher training on proper procedures

REMEMBER: THE 3 KEYS TO SYSTEM LONGEVITY

1. QUALITY DEF – API certified, properly stored, never contaminated 2. CLEAN FILLING – Dedicated equipment, clean procedures, every time 3. COMPLETE REGENERATION – Let the DPF do its job, don’t interrupt

Additional Resources

For more information on DEF and DPF system requirements, refer to these official sources: Thank you for reading our DPF and DEF System Maintenance Guide.

• EPA Diesel Exhaust Fluid Guidelines – Official EPA guidance on DEF systems and regulations
• API Diesel Exhaust Fluid Certification Program – Find API-certified DEF products that meet ISO 22241 standards
• API Engine Oil Categories – CK-4 and FA-4 oil specifications for diesel engines

This DPF and DEF System Maintenance Guide is provided for educational purposes. Always consult your vehicle manufacturer’s specific recommendations.

Questions? Contact RDK Truck Sales – Your Trusted Partner in Refuse Equipment Since 1997

Tampa, Florida | www.rdk.com