Investigations
Brake Master Cylinder Internal Leak
NHTSA Preliminary Evaluation PE11020 - closed, opened 2011-05-23 and involving the NISSAN NISSAN.
NHTSA investigation PE11020 is a Preliminary Evaluation opened on 2011-05-23 and currently closed. The subject of record is NISSAN NISSAN, which places this file inside the Office of Defects Investigation queue for NISSAN. Latest activity on this investigation was logged on 2012-03-14 - NHTSA updates that field whenever an Information Request goes out, a supplement is filed, or a status change is recorded in the public docket.
A Preliminary Evaluation like PE11020 is the entry point of the federal defect-investigation process. NHTSA engineers scan complaint databases, field reports, and manufacturer data to decide whether an Engineering Analysis is warranted, whether a voluntary recall is already sufficient, or whether the pattern does not rise to a defect finding.
Investigators summarized the matter as follows: "The Office of Defects Investigation (ODI) opened PE11-020 to investigate possible brake performance loss due to brake fluid leaking from the master cylinder into the brake booster in the subject vehicles. A total of 237..." Investigations are the early-warning layer of the federal auto-safety system, sitting upstream of formal recalls and defect orders. Whether this one closes without action or escalates into an Engineering Analysis, the full history stays in the ODI archive so researchers, litigators, and buyers can pull the paper trail at any time. Related NISSAN files, listed below, give context on whether this is an isolated concern or part of a broader pattern across the brand.
Investigation Summary
The Office of Defects Investigation (ODI) opened PE11-020 to investigate possible brake performance loss due to brake fluid leaking from the master cylinder into the brake booster in the subject vehicles. A total of 237 complaints were identified by ODI and Nissan. The majority of complaints and warranty claims reported that brake malfunction indicator lamp (MIL) illumination as the only symptom of a problem. Only 12 complaints alleged any effect on brake performance and in each of these the drivers were able to stop the vehicles without incident. No crash claims could be attributed to the alleged defect. Returned part analysis data provided by Nissan showed that most of the master cylinders replaced under warranty did not have a leak condition. These replacements may have resulted from brake MIL illumination due to pad wear. For most of the warranty claims, in a few cases where a master cylinder leak was found, Nissan's testing showed that the leaks were extremely slow and would require thousands of miles or months of driving before brake performance could be affected. After an extensive study of replaced master cylinders for a presumed leak, Nissan was unable to identify any concern with the parts or design of the subject components that could affect brake performance. Nevertheless, Nissan does recognize a concern with premature brake MIL illumination and has decided to address this problem by conducting a voluntary service campaign covering approximately 1.17 million model year 2007 through 2012 Altima vehicles (up to June 25, 2011 production, the date of Nissan's running change for the longer life brake pad). Nissan's owner letter for the service campaign states, "As your brake pads wear over time, the brake fluid level in the master cylinder reservoir will drop and may cause the brake warning lamp to illuminate.” Although this is a normal condition, there has been concern that the brake warning light illumination may be caused by a slow fluid leak over time." N
About This Investigation Type
A Preliminary Evaluation (PE) is the first phase of NHTSA's investigation process. It is opened when the agency identifies a potential safety defect pattern, usually triggered by consumer complaints, manufacturer reports, or field monitoring. During a PE, NHTSA gathers information to determine whether a formal engineering analysis is warranted.
Other NISSAN Investigations
Driver Airbag Inflator Rupture
Inner Tie Rod Failures
Side curtain air bags may deploy inadvertently
Reduced Power After Engine Stall
Loss of motive power due to broken crankshaft with no ability to restart.
Data from NHTSA Office of Defects Investigation. Cross-references: NHTSA recall campaign API and NHTSA FARS where fatality records overlap. PlainCars does not rate or recommend vehicles. about how PlainCars sources NHTSA data.
Read our methodology - how this data is sourced, computed, and verified.