Nice job. Thats as good as a duct tape repair. Im sure you limited how much you used but where you not concerned it would travel thru the rest of the air system?
How did you get into or keep it in just the sleeper side of the system?
Granted it was a pin hole of a leak. I pulled the spring out, couldn't find a replacement without ordering one, so I thought I'd give it a try. Squirted straight into the top, hooked the air line back up and shot some air into it and rolled it around to the hole. Plugged it right up. Disconnected, poor out the excess and mounted it up. I have done away with the sleeper leveler valve because it was causing my air pump to run too much with todays rough roads, I found it kept airing up and releasing air as we traveled, the valve did not leak at a stand still. I have a manual air switch on the dash along with the switch for my Donvel airsprings on the front. The Slime has never come back up stream or showed up anywhere.
AS a side note, I tried patching a hole in one of my Donvels and the hole wouldn't patch as it was just a bit too large.
Not a permanent fix but had me going in a tight, and still going.