The worst 2021 Peterbilt 520 problems
Ranked by number of owner complaints. Mileage and cost come from what owners wrote.
Problems by type
Tap a problem to see which part fails, at what mileage and in which other years.
Recalls 6
Suspension: multiple axle
- What is wrong
- PACCAR Incorporated (PACCAR) is recalling certain 2015-2023 Peterbilt 320 and 520 refuse trucks equipped with Haulmaax/EX suspensions. The suspension tracking rod brackets may fail and detach from the forward drive axle, causing the axle to become unstable.
- Risk
- An unstable axle can decrease vehicle stability and control, increasing the risk of a crash.
- Remedy
- Dealers will inspect the welds and add an additional bracket between the tracking rod bracket and axle housing, as necessary, free of charge. Owner notification letters are expected to be mailed February 14, 2023. Owners may contact Peterbilt's customer service at 1‑940‑591‑4220. PACCAR's number for this recall is 22PBL.
Recall number 22V939000 · Recall details
Service brakes, air
- What is wrong
- PACCAR Incorporated (PACCAR) is recalling certain 2020-2021 Peterbilt 520 vehicles. The quick release valve on the rear brake signal hose may be missing. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 121, "Air Brake Systems."
- Risk
- A missing quick release valve cannot ensure correct rear brake release timing, increasing the risk of a crash or injury.
- Remedy
- Dealers will inspect the vehicles for a missing quick release valve, and install one if necessary, free of charge. Owner notification letters were mailed on October 7, 2021. Owners may contact PACCAR's customer service at 1‑940‑591‑4220 (Peterbilt). PACCAR's number for this recall is 21PBK.
Recall number 21V720000 · Recall details
Fuel system, diesel: fuel injection system: fuel rail
- What is wrong
- PACCAR Incorporated (PACCAR) is recalling certain 2018-2021 Peterbilt 337, 348, 365, 367, 520, 567, Kenworth T270, T370, T440, T470, T800 and T880 vehicles. The sealing washer may not seat correctly in the pilot bore holes, allowing the high pressure fuel rail assembly to leak.
- Risk
- A fuel leak in the presence of an ignition source increases the risk of a fire.
- Remedy
- Dealers will inspect the rail threads and fuel lines, and replace the rail as necessary, free of charge. Owners may contact PACCAR customer service at 1‑425‑828‑5888 (Kenworth) or 1‑940‑591‑4220 (Peterbilt). PACCAR's numbers for this recall are 21KWC and 21PBD.
Recall number 21V391000 · Recall details
Steering: column
- What is wrong
- PACCAR Incorporated (PACCAR) is recalling certain 2015-2021 Peterbilt 320 and 520 vehicles. The steering column support structure may crack or break in certain right-hand, stand-up drive models.
- Risk
- If the steering column loosens from the mounting structure, steering control can become affected, increasing the risk of a crash.
- Remedy
- PACCAR will notify owners, and dealers will inspect the 520 models right hand stand-pp steering column structure and replace it if cracks are present, as well as add additional support brackets to the new (if replaced) or existing structure, free of charge. Additionally, for the 520 models, dealers will install a large gusset with triangulating support for the column bracket, free of charge. Owner notification letters were mailed July 30, 2021. Owners may contact Peterbilt customer service at 1‑940‑591‑4220. PACCAR's number for this recall is 21PBA.
Recall number 21V004000 · Recall details
Electronic stability control (ESC)
- What is wrong
- PACCAR Incorporated (PACCAR) is recalling certain 2020-2021 Peterbilt 520 vehicles. The stability control brake relay may have the Spring Brake Modulating (SBM) Valve or the lift axle hose incorrectly connected.
- Risk
- A stability control event meant to only actuate the ABS controlled wheel ends could actuate lift axle brakes or modulate park brake chambers and could possibly de-stabilize the vehicle, increasing the risk of a crash.
- Remedy
- PACCAR will notify owners, and dealers will inspect the suspect chassis and correct the brake relay plumbing if needed, free of charge. PACCAR has issued owners an interim notification on January 4, 2020. Owner notification letters were mailed on January 25, 2021. Owners may contact Peterbilt customer service at 1‑940‑591‑4220. PACCAR's number for this recall is 20PBF.
Recall number 20V739000 · Recall details
Power train: axle assembly
- What is wrong
- PACCAR Incorporated (PACCAR) is recalling certain 2020-2021 Peterbilt 348, 365, 367, 389, 520, 567 and Kenworth T800, T880, W900, W990 vehicles equipped with Watson and Chalin steerable lift axle suspension systems (model SL2065). The axles may have lower rear pivot bolts that are not long enough to sufficiently engage the locking feature of the corresponding nuts.
- Risk
- The short screws can cause the hardware to separate from the suspension system and become road hazards, increasing the risk of a crash and/or injury.
- Remedy
- PACCAR will notify owners, and dealers will inspect suspect chassis and replace the pivot bolts, as necessary, free of charge. The recall began September 29, 2020. Owners may contact Kenworth customer service at 1‑425‑828‑5888 and Peterbilt customer service at 1‑940‑591‑4220. PACCAR's numbers for this recall is 20PBE and 20KWC.
Recall number 20V506000 · Recall details
Technical service bulletins for the 2021 Peterbilt 520 58
Bulletins tell dealers how to fix known problems. A warranty extension means the manufacturer pays for that repair for longer.
- "KW & PB 14 fuel injector part numbers (seven for MX-11 and seven for MX-13 engines) have been added to...
- 7/700 Service Agreement
- This optional software update is expected to be available after 10/30/2026 for chassis equipped with EMY...
- An upgraded power steering pump is available for certain Model 520 chassis with a RHSU or dual steering...
- "Kenworth: Dealers should check the chassis list and SIR weekly for VIN changes
- The procedure has been updated to include additional steps for verifying the software level on the vehicle...
- The verbiage in the Introduction section has been updated.
- This optional software update is now available for chassis equipped with EMY 2021B-2023 PACCAR MX-11 and...
- The Condition, Chassis Affected, Service Action, Warranty, and Procedure sections have been updated to...
- "The software is not yet available
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Questions about the 2021 Peterbilt 520
Is the 2021 Peterbilt 520 reliable?
Owners have filed 0 complaints about the 2021 Peterbilt 520.
What is the most common problem with the 2021 Peterbilt 520?
There are not enough complaints to tell.
How many recalls does the 2021 Peterbilt 520 have?
6 recalls, covering suspension, service brakes, air and fuel system, diesel.
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