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Service bulletins for the 2020 Peterbilt 520

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

52 on file from NHTSA, as of 2026-10-19.

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Bulletins, newest first
02-1602021-03-10. Service bulletin. VISIBILITY; EQUIPMENT; EQUIPMENT ADAPTIVE/MOBILITY; VISIBILITY:WINDSHIELD WIPER/WASHER. Information Only – Windshield washer pumps have a high No Trouble Found rate. Washer pumps may fail to spray due to a clogged filter.
20 PBF2021-01-06. Service bulletin. PARKING BRAKE; SERVICE BRAKES, HYDRAULIC; ELECTRONIC STABILITY CONTROL (ESC). Safety Recall: Interim Dealer Notification - Peterbilt has decided that a condition affecting vehicle stability may exist in certain Model 520 vehicles built from 9/26/2019 through 7/22/2020 with stability control and a spring brake modulator valve (SBM) or lift axle. The Stability Control Relay may have been plumbed incorrectly, which could cause a stability event that may actuate the lift axle brakes or modulate the park brake chambers, which could destabilize the vehicle. This bulletin will be updated as soon as an affected chassis list is defined and a repair procedure is developed.
13-0552020-11-05. Service bulletin. EQUIPMENT ADAPTIVE/MOBILITY; EQUIPMENT; SERVICE BRAKES, AIR. Fix as Fail: Peterbilt has introduced an improved mounting bracket for low mount air tanks for vehicles built between January 01, 2017 and July 06, 2020. Torsional vibration may stress the currently-installed brackets and cause them to fail near the bottom of the frame rail.
20PBE2020-10-06. Service bulletin. POWER TRAIN; EQUIPMENT. Safety Recall: Peterbilt has decided that a condition could exist in certain model 348, 365, 367, 389, 520, and 567 vehicles built between 11/19/2019 and 4/09/2020. Vehicles equipped with Watson & Chalin SL2065 lift axles may have lower rear pivot bolts that are not long enough to sufficiently engage the locking feature of the corresponding nuts. In some cases, this condition may cause a loss of clamp load of the pivot joint (arm to axle). Extended use of the lift axle in this condition can result in foreign object debris on the roadway, increasing the risk of a crash and/or injury.
14-0272020-10-06. Service bulletin. STRUCTURE; EQUIPMENT. Information only: In 2020, Peterbilt and Kenworth began using the same M10, M12, M16, and M20 frame fasteners on all vehicles. Torque specifications for these fasteners are different from previous fasteners.
20PBD2020-09-03. Service bulletin. EQUIPMENT ADAPTIVE/MOBILITY; STEERING; EQUIPMENT. Safety Recall: Model 520 vehicles with Right-Hand Stand-Up (“RHSU”) configuration built between February 15, 2019 and December 20, 2019 may have incorrect steering assist cylinder bracket bolts installed, which prevents proper retention of these bolts.The steering assist cylinder bracket attached to the right front spring bracket with these bolts may also be damaged. The bolts installed may not have the required thread lock and this could result in loose or missing hardware. This may cause the bracket to flex or break and cause damage to adjacent components or lock up steering. Resolution is to remove and reinstall the steering gear assist bracket bolts with thread locker.
13-0542020-08-05. Service bulletin. SERVICE BRAKES. Fix-As-Fail - Bendix New-Gen Lightweight Steer Axle Drum Brake Spider Cracking
32-0152020-07-03. Service bulletin. ELECTRICAL SYSTEM. Information Only: This bulletin provides dealers with a battery warranty quick reference guide to ensure the appropriate tests for battery warranty are performed in order to prevent battery warranty claims filed with incorrect or incomplete information.
43-0672020-07-03. Service bulletin. STRUCTURE; ENGINE AND ENGINE COOLING:EXHAUST SYSTEM. Fix as Fail: For all conventional models, except 387/587, equipped with Side-of-Cab (“SOC”) exhaust and built from 03/6/2006 to 1/20/2020, the clamps that secure the SOC exhaust stacks may not be tightened properly. This may allow the exhaust stack to rotate and contact the cab or sleeper.
34-0872020-07-03. Service bulletin. ELECTRICAL SYSTEM. Non-Safety Campaign: Peterbilt has determined that certain RHSU model 520 trucks, built from 7/16/2018 to 3/20/2020, may have been equipped with a Main Cab Harness that enables the Door Alarm to sound when it should be disabled. Model 520 vehicles with this configuration should have the door alarm disabled when the passenger door is open and the vehicle is in drive mode.
11-0012020-06-02. Service bulletin. POWER TRAIN. Information only: Hendrickson Softek front axle maintenance intervals and requirements.
20PBB2020-04-03. Service bulletin. SERVICE BRAKES, AIR:SUPPLY:QUICK RELEASE VALVE. Safety Recall: Peterbilt has decided that certain Model 320 and 520 trucks built between 2/20/2015 and 7/16/2019 may have been built without a quick release valve. The absence of this valve could affect rear brake timing on certain vehicles equipped with a tri-drive or liftable tag axle and Dual Seated or Right Hand Stand-Up steering configurations. Resolutoin is to inspect for a quick release valve installed, and if there is not one, to install a quick release valve.
19PBF2020-04-03. Service bulletin. STEERING. Safety Recall: Peterbilt Motors Company has decided a defect, which relates to motor vehicle safety, may exist in certain Model 520 vehicles with Right Hand Stand Up (RHSU) configuration built between June 15, 2018 and February 14, 2019. Vehicles may have an improperly supported steering gear assist bracket due to the incorrect spring bracket installed. The spring bracket may be missing 3 drilled and tapped holes which will provide additional support for the steering gear assist bracket. An improperly supported steering gear assist cylinder bracket may break and cause damage to surrounding components and/or lock up the steering, increasing the risk of a crash. Resolution is to inspect and verify the steering assist bracket is installed with 5 required bolts. If 5 bolts are not installed, a new bracket will be installed.
32-0162020-04-03. Service bulletin. EQUIPMENT. Information Only: Proper jump-starting voltage will eliminate high voltage related issues and equipment damage.
19PBF2020-02-05. Service bulletin. STEERING. Safety Related Campaign - Interim Notification: Peterbilt Motors Company has decided a defect, which relates to motor vehicle safety, may exist in certain Model 520 vehicles with Right Hand Stand Up (RHSU) configuration built between June 15, 2018 and February 14, 2019. Vehicles may have an improperly supported steering gear assist bracket due to the incorrect spring bracket installed. The spring bracket may be missing 3 drilled and tapped holes which will provide additional support for the steering gear assist bracket. An improperly supported steering gear assist bracket may flex or break and cause damage to other components or cause the steering to lock up. This bulletin will be updated as soon as parts become available for the repair.
03-0712020-01-04. Service bulletin. ELECTRICAL SYSTEM:SOFTWARE. Information Only - Vehicles built with NAMUX software from 2013 to present may experience accuracy issues with the tachometer. The issue can be temporarily resolved using any one of the included procedures.
19PBG2020-01-04. Service bulletin. POWER TRAIN. Safety Recall: Peterbilt Motors Company has determined that a defect, which relates to motor vehicle safety, may exist in certain model 348, 367, 389, 520 or 567 vehicles manufactured between November 22, 2019 and December 5, 2019. Output shafts may not have been correctly heat-treated and could break near the pinion nut. Resolution is to inspect the driveshaft to verify the julian date, and if witin th esupect date rate,, replace the output shaft.
02-1532019-12-04. Service bulletin. STRUCTURE. Information only: Some model 320 and 520 vehicles built before 3/11/2019 may experience loss or loosening of doghouse insulation. Reference the procedure in the attachment section to properly remove and replace the insulation.
01-0752019-12-04. Service bulletin. ENGINE AND ENGINE COOLING. Information Only: This bulletin provides guidance for repairing an air-conditioning system after internal failure of the A/C compressor.
TIB43-0622019-10-04. Service bulletin. EQUIPMENT; ENGINE AND ENGINE COOLING:EXHAUST SYSTEM. Information Only – This bulletin provides information about the California Air Resources Board (CARB) Periodic Smoke Inspection Program (PSIP) and Heavy Duty Vehicle Inspection Program (HDVIP).
42-0562019-09-05. Service bulletin. ENGINE AND ENGINE COOLING. Fix-As-Fail -“ Composite fittings used in the cooling system may crack, resulting in coolant leaks. Brass fittings are available to replace the composite fittings.
42-0582019-09-05. Service bulletin. ENGINE AND ENGINE COOLING. Fix-As-Fail: Two separate causes have been identified as root cause of intermittent low coolant indicator illumination.
19PBC2019-08-02. Service bulletin. EXTERIOR LIGHTING; ELECTRICAL SYSTEM. Safety Recall: Vehicles fail to confirm with FMVSS/CMVSS No 108 Table 1-a requirements which requires 2 red stop lamps. Vehicles were equipped with additional amber stop lamps which may illuminate when the brake is applied, and may confuse other drivers. Resolution is to remove the amber stop lamps and associated wiring.
34-0662019-07-08. Service bulletin. ELECTRICAL SYSTEM. Information Only - Quick Reference Guide for Electric harness damage repairs.
19PBB2019-06-10. Service bulletin. ELECTRICAL SYSTEM. Safety Recall: INTERIM NOTIFICATION - Peterbilt Motors Company has determined that a defect, which relates to motor vehicle safety, exists in certain model year 2017, 2018, 2019 and 2020 Model 520 vehicles manufactured between October 17, 2016 and March 04, 2019 with left hand or right hand single steer Power Distribution Center (PDC) harnesses. The power wire to the PDC may be inadequate and unable to accommodate the current draw. This can cause the wire to overheat and potentially melt the cab power harness connector. This could cause a loss of power to the cab and engine, which may result in the engine shutting down. A sudden loss of engine power could increase the risk of a crash.

The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.