The problem
Honda (American Honda Motor Co.) is recalling certain 2016-2020 Acura ILX vehicles. Contaminated brake fluid may cause a seal inside the brake master cylinder to deform, which can cause an internal brake fluid leak and reduce brake function.
The risk
Reduced brake function can extend the distance required to stop, increasing the risk of a crash or injury.
The fix
Dealers will replace the brake master cylinder, free of charge. Owner letters were mailed May 4, 2026. Owners may contact Honda's customer service at 1-888-234-2138. Honda's number for this recall is RN5. Vehicle Identification Numbers (VINs) involved in this recall will be searchable on NHTSA.gov beginning December 17, 2025. The information in your report suggests that Honda (American Honda Motor Co.) may have been aware of this issue more than five business days before filing a report with NHTSA. Please be reminded that under Federal law, this agency is to be notified of all safety defect and/or noncompliance decisions within five business days. 49 CFR 573.6 Significant civil penalties can be assessed for this violation.
Recall details
| NHTSA campaign | 25V-859 (25V859000) |
|---|---|
| Manufacturer number | RN5 |
| Manufacturer | Honda (American Honda Motor Co.) |
| Component | Service brakes, hydraulic › Foundation components › Master cylinder |
| Report date | December 11, 2025 |
| Owners notified | May 1, 2026 |
| Vehicles affected | 70,658 |
| Initiated by | NHTSA investigation |
Vehicles covered
Owner complaints about the brakes
Frequently asked questions
Is the recall 25V-859 repair free?
Yes. Acura dealers will fix the problem at no cost: Dealers will replace the brake master cylinder, free of charge. Owner letters were mailed May 4, 2026. Owners may contact Honda's customer service at 1-888-234-2138. Honda's number for this recall is RN5.
How do I know if my car is included?
Not every vehicle of the listed model years is affected — the recall covers 70,658 vehicles built in a certain window. Check your 17-character VIN with our VIN recall check or at nhtsa.gov/recalls.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.