Hey guys Im currently dealing with a strange problem in my car. When I do a good pull, or accelerate really fast, my car will suddenly brake rather hard on its own. Its not braking too harshly but its definitely significant and doing it on its own. I dont have a feature on my car that would make it do that so its not that. Something to note is that I need to replace my timing belt because its making that rattling noise and I know that I need to replace my brake pads as well (maybe they are sticking too each other because they are that bad but to me that does not make sense because Im not engaging with the brakes when this problem occurs, Im simply letting off the throttle when the problem occurs). Anybody ever deal with an issue like this? Could it be one of the two things that I need to replace? Any advice would be greatly appreciated..
Typically it happens in my higher gears like 3,4,5,6 but this could also be because I do usually do pulls in first or second gear.

Mileage- 101k

 

Could it be a resonance of the loose timing chain that causes drag on the valve train gear as the chain vibrates?