Rear brake caliper bolt leak

I recently replaced the pads on the mustang. I accidentally also untightened the bolt on the caliper that connects it to the brake fluid line. I tightened it again but I can see it leaking when I turn on the engine and pump the breaks. This happens only on the rear passenger side and all of the three other wheels are find. I did not replace any calipers. The only work that was done on the caliper was to push the pistons inside.

I have read about washers needed to be changed or even replacing the caliper.

Any pointers would be highly appreciated.

Thanks.

Thanks

Thanks. I will try to do that and hope it works.

I ended up getting a new caliper because I couldn't push the piston far enough even with the loaner tool from autozone. It came with new copper washers and eventhough one of the washers did not thread in the bolt (like the original one) atleast there are no leaks.