Opinion ID: 776872
Heading Depth: 4
Heading Rank: 2

Heading: The Loss of Braking Power

Text: 52 Jarvis also presented evidence at trial that sudden acceleration not only would open the throttle to her Aerostar but also would decrease significantly her ability to restrain the vehicle by pumping the brakes. Pope, Jarvis's expert, testified that the Aerostar had vacuum power brakes that draw their vacuum from the engine. When accelerating at full throttle, Pope testified, the engine does not create the normal vacuum that assists in braking. An additional reservoir of vacuum could be depleted by pumping the brakes, as Jarvis testified she did in this case. The expert concluded that under those circumstances []it will feel to a person like they've lost their brakes, they're pushing and nothing is happening. 53 Calling this theory into question when ruling on Ford's motion for judgment as a matter of law, the district court pointed to testimony by Pope on cross-examination acknowledging that, assuming that the dump valve was working properly and that it would engage when the brake pedal was depressed approximately half an inch, in a normal pumping phase, the dump valve is always going to be open, so you are never going to be out of vacuum assist. Jarvis, 69 F.Supp.2d at 598. Construing the evidence in the light most favorable to Jarvis, Pope's statement does not establish whether he was referring to a single depression of the brake pedal or how long he assumed the pedal was depressed. These additional factors are crucial for determining when Jarvis's brakes would exhaust the vacuum reservoir making it difficult to slow the vehicle. Admittedly, no record exists of how many times Jarvis pumped the brakes, how long each stroke lasted, or how far she depressed the pedal in each stroke. Such a record would allow a more exact analysis of how the depletion of the vacuum reservoir may have been counterbalanced by the engine replenishing the vacuum, if the dump valve were functioning properly and the sudden acceleration were interrupted every time the brake pedal was depressed. Given the absence of this information and the uncertainty as to the context of Pope's comment, we do not view this isolated portion of Pope's testimony as discrediting other testimony in the record concerning the detrimental effect of pumping the brakes on the ability to stop a vehicle accelerating at full throttle. 54