NHTSA service bulletin

NHTSA Service Bulletin 11026416: 2021-2026 Peterbilt 520

Official manufacturer communication context for 2021-2026 Peterbilt 520, with affected products, buyer checks and links into Carchieve recall, problem and VIN research.

NHTSA service bulletin 11026416 summary graphic for 2021-2026 Peterbilt 520
11026416NHTSA document ID
Warranty program / extensioncommunication type
2affected product rows
80/100quality score

Reviewed June 2026 from NHTSA manufacturer communication and service bulletin records. Carchieve is independent and not affiliated with any vehicle manufacturer or government agency.

Quick answer

Repair procedures and warranty information for model 520EV are now available. The cab heater coolant system on Peterbilt 579EV and 520EV models may not deaerate properly, causing pump malfunctions and inadequate cab heating. Update coolant deaeration return line parts and procedures are now available to release trapped air back to the reservoir.

What this bulletin may mean before buying

Treat this as service research, not a verdict on one car. Before you buy, compare this communication with official recall campaigns, model-level owner complaint patterns, and the exact vehicle’s VIN-decoded specifications. A bulletin can help you ask a seller or dealer sharper questions about software updates, known repairs, warranty extensions and service history.

Affected products listed in this communication

MakeModelModel yearsBuyer note
Peterbilt5202021-2026Ask for service records and run the exact VIN before purchase.
Peterbilt5792021-2026Ask for service records and run the exact VIN before purchase.

Buyer checklist

  1. Run the 17-character VIN and confirm the year, make, model, engine and equipment match the listing.
  2. Check recall campaign pages for safety actions that may require dealer repair.
  3. Compare this bulletin with common problem pages for the same model and component area.
  4. Ask the seller or dealer whether the bulletin procedure, update or inspection has already been completed.
  5. Use the used-car buying checklist and get an independent inspection.

Frequently asked questions

What is NHTSA service bulletin 11026416?

Repair procedures and warranty information for model 520EV are now available. The cab heater coolant system on Peterbilt 579EV and 520EV models may not deaerate properly, causing pump malfunctions and inadequate cab heating. Update coolant deaeration return line parts and procedures are now available to release trapped air back to the reservoir.

Is a service bulletin the same as a recall?

No. A recall is a safety campaign with a required remedy for affected VINs. A service bulletin or manufacturer communication usually describes diagnostic, repair, software, warranty or service information.

How should a used-car buyer use this bulletin?

Use it as a research signal. Compare it with recalls, owner complaints, service records, a VIN report and an independent inspection before buying.

Check the exact VIN before you buy

Model-level pages show public safety patterns. A full VIN report helps confirm the exact vehicle, decoded specs, recall applicability and buyer checks.

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