A/N: Here's an insight into how my mind works: I thought 'My last story was pretty sad. I should write something happy.' And then 'something happy' turned into 'the Winter Soldier crying a lot.' I don't know. I just don't know.
All machines require maintenance.
The Soldier's body is no exception. He needs recalibration when he is extracted from the tank and likewise when he is returned to it. The technicians supply the necessary sustenance to fuel his body and maintain the length of his hair and nails. They evaluate his performance and make the necessary alterations to the chemicals that supplement his natural biological processes. They remove the excess hair from his face and the areas of his body where it would interfere with their monitoring equipment.
It is not dissimilar to when the Soldier cleans or field strips and reassembles his rifle, except of course a machine cannot sustain itself. He tries to be as helpful as he can when repairs are necessary. He learns the signs associated with various damages and tries to fix what he can.
Besides pain, the most obvious indicators of malfunction are the leaks.
There is the red leak, warm and coppery, that indicates punctures or rips. The bitter, burning leak that forces its way violently from his throat when he is exposed to weaponized chemical agents. The clear fluid from blistered skin after burns or excessive friction. There is the acrid leak between the legs that relieves pressure when he is detained for long periods without a proper receptacle, and the rarer viscous white liquid from the same area that reduces a very different stress.
The strangest is the clear and salty fluid that runs from his eyes.
Physical stress and pain can provoke it, and at first he believed it was a release of excessive pressure. But direct contact of objects with the eyes or exposure to chemicals, dust, or other fine particles also triggers the release. The Soldier then decides the leak is provoked by irritation, be it external or internal.
Except sometimes it happens when there is no discernible catalyst.
He will be checking a target's pulse and feel leakage itching against his face. Or he will be midway through a mission report and find his eyes are hot and dripping. Sometimes it happens when he is just standing, awaiting orders. The Soldier cannot find any connecting factor between the incidents, save for a faint and dull ache within.
This makes him fear internal injury, but the technicians are not interested in investigating the cause. Sometimes his handlers will strike him for it, but beyond that the malfunction is ignored. The Soldier has learned that tilting his head back and keeping his eyes wide tends to keep the leakage contained. Whatever the error, it does not compromise his overall functioning. It is always over quickly.
Until he is in the Smithsonian.
The Soldier is looking at a photograph of James Barnes and Steve Rogers and he is leaking, dripping rapidly and all over. It goes on for hours, far longer than ever before that the Soldier can remember. The leak inflames his face and starts another malfunction in his sinuses and, most alarmingly, begins to disrupt his breathing.
Perhaps he is designed to fall apart without HYDRA's repair. Perhaps he was simply built to break after functioning for a set period; the Soldier thinks he remembers being told that they only required his services "one more time." But eventually the leak stops, the inflammation fades, and his breathing returns to normal. He is not yet damaged beyond salvaging.
When he is reunited with Steve Rogers, the leak begins again.
He bites his lip, trying to will the malfunction to cease. Steve is smiling, and that means he is happy. He will not be happy if he sees the Soldier is damaged goods. If he is visibly faulty, Steve may not want him back at all. He tries stem the flow, tilting his head and refusing to blink, but Steve is holding him tight and he can't keep the fluid from overflowing.
When Steve pulls away, still smiling, there is liquid from his eyes as well.
"I've damaged you," the Soldier says, horrified. His targets and the HYDRA agents, they would also leak when they were injured. He trails a shaking hand down Steve's face, wiping away the moisture. He waits to be punished or sent away. He doesn't care what happens to him as long as Steve can be repaired.
But Steve shakes his head, wiping at the Soldier's face in return. "No, Bucky," he says. "I'm fine. For the first time since you fell, I'm whole."
The Soldier doesn't understand, but Steve says he is all right and the space inside the Soldier that usually aches when the leak occurs is not sore and gaping now. It feels repaired, filled, and Soldier is smiling despite the fluid down his face. The leak doesn't matter. Now that he is back with Steve, he can do more than just function. He can thrive.