 Re: Disc Brake Actuator
My guess (based on your description) is that when you apply the brakes, they won't work and fluid will be forced out where the fitting was.
The solenoid is in line with the brake lines. Some solenoids (the better ones) have an additional hose returning to the master cylinder. If it is this fitting that broke off, and you can get any remaining piece out of the cylinder, you can buy a plug at the auto parts store and plug it. Your brakes will work and yo should be able to back up. It will function as a "non bleed" solenoid.
If the solenoid is broken off the cylinder, and you must move the trailer to get it repaired, there is often a manual brake lockout intended to be used when backing if you don't have a solenoid. Activate this manual lockout (you may have to be creative as they are often designed to deactivate when the trailer is being pulled forward) and you will be able to move the trailer with no brakes and no mess.
Remember that you have no brakes so drive very carefully. Try to stay out of traffic and anticipate stopping at traffic lights, etc. | 
