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2000 subaru outback stalls when braking

hi all, mine is an outback, which yesterday when having to brake suddenly in a store parking lot, it caused the car to stall. i have noticed in times past that during night time driving, when applying the brakes, the lights will momentarily dim. any ideas ?

If the battery is more than four years old, buy a new one. Otherwise, maybe a weak alternator, and otherwise, how’s your car’s idle in drive? Is it at about at least 1,000 rpm’s and is it consistent? If not, you have some other problem.

thanks for your response. the battery is only 2 yrs old. while idling in drive, its a little less than 1000rpm at first, then it will slowly drop to around 750 & stay there. it also does not shake or sputter while idling, but is rather smooth.

Once you stop, what happens if you apply the parking brake, take you foot off the brake and then put your foot back on. What I am trying to do is to determine if it is the slowing down or the foot on the brake that is causing the problem.

"Is it at about at least 1,000 rpm’s?"
Hopefully not!

The correct idle speed for a warmed-up Subaru 4-cylinder engine is between 600-700 RPMs.
If the engine is idling at 1,000 RPMs after it is warmed-up, then that is an indication of problems–possibly with the IAC.

For the OP’s situation, I would explore possibilities of a problem with the power brake booster.
This could be a vacuum problem that is stalling the engine when the brake is applied.

thanks. the idle speed after the warm up is around 660 in park, & a little less than that in drive. when applying the (foot) brake when the emergency brake is on, whether in park-neutral-or drive, the rpm needle will shoot up about 100 more rpm, then go back down.