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2011 Ford F-150 NHTSA investigation EA15006

Ford Engineering Analysis EA15006: Brake Vacuum Pump Failure

2011 Ford F-150

Brake Vacuum Pump Failure

Service Brakes, Electric
Service Brakes, Hydraulic:Power Assist
Service Brakes, Hydraulic:Power Assist:Vacuum

Summary
On February 15, 2016, Ford Motor Company initiated Customer Satisfaction Program 15N05 to extend warranty coverage for the electric vacuum pump in certain model year (MY) 2011 through 2012 Ford F-150 pickup trucks equipped with 3.5L GTDI engines.The program extends coverage for up to 10 years of service or 150,000 miles from the warranty start date of the vehicle, all vehicles are eligible for the program through July 30, 2016 regardless of mileage.Ford's program covers all repairs related to electric vacuum pump (EVP) malfunctions including excessive noise, vibration, or change in brake pedal feel while applying the brakes at cold start. Ford states that the engine intake manifold is the primary source of vacuum for the brake booster and is fully compliant to motor vehicle safety standards without the supplemental vacuum supplied by the EVP.The company also contends that failure modes related to the EVP are progressive and provide warning to operators by way of noise and vibration before an operator to experience any temporary change in brake pedal feel.ODI's analysis of warranty data found that the majority of claims involved consumer concerns with EVP noise or vibration from the left front fender area when the vehicle is first started. Continued operation in this mode with pump motor noise will eventually result in the EVP seizing or becoming non-functional.Component failure analysis indicated that Ford and its supplier, Continental, identified a pump crank drive corrosion condition due to moisture entry through the vacuum intake.Corrosion damage to EVP internal components may eventually result in a blown fuse in the power distribution box and total loss of EVP function.Analysis of consumer complaints, field reports, and warranty data related to EVP failures found thatincidents predominantly occurred in driveways and parking lots in the periods immediately after cold engine starts.Many consumers operated their vehicle for some period of time with a blown EVP fuse without realizing that the pump had failed or that the vehicle had a brake system malfunction.Consumers who did experience braking performance issues reporteda temporary hard brake pedal condition at start-up followed by more consistent normal pedal feel after few seconds.On June 22, 2015, Ford developed a remedy procedure and issued TSB 15-0105 instructing dealers to replace the vacuum pump and install a new vacuum pump harness kit. In addition to reviewing test data submitted by Ford, ODI assessed safety risks associated with the alleged defect under various operating conditions, including: 1) baseline system performance with full engine and EVP vacuum available using exemplar parts, 2) disabled EVP and booster vacuum regulated to simulate worst case conditions for engine intake manifold vacuum supply to the brake booster (approximately 300 mbar); and 3) all source vacuum to the brake booster removed and Optimized Hydraulic Braking (OHB) mode active to represent complete loss of brake booster function (note: this condition is a more severe brake boost system failure mode than the alleged defect).ODI also analyzed all complaints and warranty claims to identify incidents alleging brake system performance concerns related to EVP failures.These analyses identified no brake performance issues or resulting changes in stopping distances either on highway or city traffic conditions.Two complaints alleging EVP malfunctions caused or contributed to rear-end collisions during attempted decelerations from road speeds are not believed to be related to the alleged defect.The EVP provides supplemental vacuum during initial start-up and idle with a cold engine.Both incidents (Continued on attachment A)
Documents (3)

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Date Opened
OCT 16, 2015
Date Closed
APR 28, 2016
NHTSA Recall #
No recall issued
  • Status:
    CLOSED
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