You are driving forward, applying the brake and about to make a complete stop (about 1-2 mph), now push the brake harder and "thump thump". It sounds like the brakes are not correctly situated or something (fuel tank) slamming into something. I also tried that In Reverse but it was smooth like butter.

Does this happen to your NX? Can you duplicate it? Thanks in advance.

 

If it sounds like metal pipes tapping each other, I've had this problem and found the brake pad wear indicators wrongly installed on the leading side rather than the trailing side of the brake pads, causing them to compress every time I brake during forward movement. Once the wear indicators have been moved to the trailing sides of the brake pads, the car makes tapping sounds during reverse now, consistent with our 2016 RX350 (with never-serviced brakes).

If you've never removed your NX's brakes, then the above solution might not be of much relevance to you. Cheers.

 

Not really Metal pipe tapping noise but more like something slamming into something...I checked the spare wheel but it is secured. Also, the brakes are still new, never replaced.

With about 100 views and 1 reply so I guess you all don't have that problem. Thanks for troubleshooting.