What is that breaks/seizes/stops working in the MINI door brake? Is it repairable?
OR
Does anyone have a good working one they could mail to me? Northern Massachusetts - price?

 

Most of the time the door brake either jams or breaks completely. They wear over time and jam, then break. Much easier to replace it than to try to repair it as it will be worn and will probably break again soon after.

Check item 4 in the picture (in the link) below for where the part is and what it looks like
door assembly

Also the door brake is here (without a photo) the part in question.
door brake (to 5/2003)

Fairly simple part to replace, although you do have to remove the door card first.

 

Fixed mine once. There are spring loaded pucks (inner end) that interlock with a metal concave recess (?... 'don't remember exactly).
Worked for about a month.
I Finally got fed up with the door slamming me in the head whilst connecting my OBDII...and bought a new one off Ebay $50.
I quickly noticed that the new bake was an improved/redesign, but looked exactly like my (16y/o) OEM.
It's been 2 years and is one of the best fixes so far

 

Genuine MINI door stay. Fair price.
I order most all my stuff from these guys. Their a MINI dealers wholesale division. Best thing I did to my 05MC. Used one I installed failed in a very short time.

https://www.bmwpartsworldwide.com/oe...MmYT1taW5pJm89