Brake problem? Need advice

[TBone250]

Just test drove my latest purchase: 2004 EZ-GO TXT with 6" drop axle lift and 24x11-10 Dirt Devils with rear flip flop seat, 6 T-125s and receiver hitches front and back with portable winch mounted up front.

I give you those details so you get an idea of the weight. So here's my question: loaded with me & another person up-front (~400lbs) should the stock brakes be strong enough to keep us from rolling backwards down a slight incline? I don't understand % of grade but I would say it was < 20 degrees and with the brakes to the floor, we slide right down the hill.

So are there upgraded brake kits I should consider or should I just check/replace my current brakes?

Last time I played golf, which has been a while, stock brakes could lock up and stop on a dime. I know I'm dealing with a much heavier cart now though.

Let me know if my expectations are just wrong.

Appreciate any advice and will have pics soon after I fix the flat from yesterday and slime the tires.