The accumulator design doesn't support a recharge. If someone had claimed to recharge one, I'd be dubious, as much of the issue is elastomer breakdown over time allowing the nitrogen gas to escape. Since you can't replace the elastomer, I'm not sure how you rebuild that.
The electric motor can be rebuilt, though it is not a common part, and if something significant needs replacing (beyond a rewind, and brushes) it can be pricey to source the parts.
You could pull apart the valve body and inspect the solenoids. I've not heard of anyone repairing the solenoids in our units, but I know some have repaired solenoids in Teves Mark II units for other applications.
If your unit is leaking, most likely the nose seal in the electric motor failed and fluid is entering the motor housing and leaking out.