Reliability report · 2021 Ford F-250 Super Duty · Updated July 2026
The 2021 is a more-sorted year: 158 complaints, less than half the 2019 total, with the same well-understood component ranking.
The homework is standard Super Duty: confirm the 6.7 diesel's fuel-system recalls (a fuel-filter-cap leak campaign plus the CP4 pump), confirm the steering-column-detachment recall, and run the usual front-end and fuel-filter checks.
Evidence: 158 NHTSA complaints · 13 recall campaigns · 6 mechanic & forum sources
Canary status
Chirping
What that means: Complaint volume falls to 158 — well under half the 2019 peak — and the truck is a settled, mature version of the aluminum Super Duty. The diesel fuel-system and steering-column recalls still need confirming, but the pattern list is calmer.
This status assumes the riskiest common powertrain — see the F-250 Super Duty engine guide.
158
Federal complaints
13
Recalls
~$10,000 (mechanic-quoted)
CP4 grenades / full fuel system
$0
Fuel-system recall remedies
Ranked by the cost of ignoring them. Every claim carries its source.
Two diesel fuel-system campaigns matter on the 2021. 22V-013 (Ford 22S01) recalls 6.7L trucks for a pinhole that can form in the secondary fuel-filter cap, leaking fuel near the engine — a fire risk — remedied by replacing both fuel filters. 24V-957 (24S78) addresses the CP4 high-pressure fuel pump (biodiesel-deposit failure) with a software update, and re-repair 26V-158 (26S17) covers first-fixes done wrong. Beyond the recalls, the CP4 remains the expensive private failure: metal from a failed pump contaminates the whole fuel system, roughly $10,000 to replace (mechanic-quoted). Confirm both recalls and inspect the lower fuel filter for metal.
What to check
Pink and cleanServiced. Proceed.
Dark brownDamage underway.
This is a 6.7L Power Stroke diesel problem. The 6.2L gas V8 and 7.3L Godzilla gas V8 don’t share it.
Which engine is in the one you found? →Fuel-system recall remedies
$0
CP4 grenades / full fuel system
~$10,000 (mechanic-quoted)
Sources: NHTSA complaint and recall databases, 2021 F-250 SD · Independent mechanic and Ford-tech channel transcripts (Super Duty)
25V-626 (Ford 25S94) recalls 2020–2021 Super Duty trucks whose steering-column upper shaft may detach, causing a loss of steering control. It is the most safety-critical recall on the 2021 and the first one to confirm remedied. This is a manufacturing/assembly defect, separate from the worn-component death wobble; a fixed truck is fully safe.
Sources: NHTSA complaint and recall databases, 2021 F-250 SD
$0
Recall remedy (25V-626)
The gas 2021 has the 7.3L Godzilla — the strong, simple, big-displacement pushrod V8 mechanics recommend for towing. The two things to watch long-term are spark plugs seizing in the aluminum heads (turning a routine change into a thread-repair or head job) and typical era oil leaks. Ask for spark-plug service history and check for leaks; otherwise this is the reassuring engine choice.
Sources: Independent mechanic and Ford-tech channel transcripts (Super Duty)
$200–$500
Routine plug service
$800–$2,500
Seized plug / thread or head repair
The solid-front-axle death wobble is inherent to the platform, though the dedicated 2017–2019 steering-damper program does not cover 2021. A worn track bar, ball joints, or tie rods can start a violent oscillation at highway speed over bumps; a new steering damper alone only masks it. Test-drive over rough pavement above 50 mph and check the front-end components for play.
Sources: Independent mechanic and Ford-tech channel transcripts (Super Duty)
$150–$400
Track bar / stabilizer link
$1,500–$3,000
Full front-end rebuild
The kinks are worked out — now it's just the standard diesel and steering-recall homework.
Free fixes at any Ford dealer. Run the VIN — “completed” isn’t always completed.