Engine Shuts Off When Braking

Everytime I need to come to a rather harder stop, where I have to kind of give the brakes more pressure than usual, my engine shuts off. What is this a sign of? I THINK I'm noticing it when I'm under 6-7 gallons of gas. I don't know if that's the only time it does it because I haven't noticed it doing above that amount. But when I brake even slightly harder than a slow stop, it just cuts my engine off. Anyone know what to check to see why it does this, or is this normal?

I'm being told that I HAVE to keep the gas above 7 gallons and it's normal for it to do this when I'm low on gas. I don't think it should do it honestly, so anyone else got a second opinion? Or is this problem all resolved by keeping my tank above 7-8 gallons? That would suck. I thought cars are made to run on low fuel sometimes and not have life threatening risks behind it. Lol. Thanks.

Oh, it's a 1990 Cadillac DeVille. Forgot to add that!

Oh, it's a 1990 Cadillac DeVille. Forgot to add that!

doug,
have you owned this vehicle from new?
or is this a second plus owner vehicle?
has the fuel pump ever been changed?
if so, if the pump and strainer were in improperly, or laying on a baffle within the fuel cell, it could be at a level higher than the bottom of the tank.
...if this isn't the case, try backing up and braking; does the vehicle cut out as well as forward? if so, could be vacuum related.
that '90, it is a 4.5l right?

chris
nrt racing
713.933.5773
Houston