Similar to Dennis, our passenger side slide opened on us, but on the freeway. Fortunately there was a Monaco dealer (Gary's RV, Eden, ID) nearby and the coach was only a month old. HWH paid to replace the offending/leaking solenoid. Our coach has been parked by the house for 16 months, and a couple weeks ago I noticed the passenger side slide popped out a half inch at the bottom, like your situation. The solenoids work in pairs, for each slide, one in and one out; and HWH strongly recommends you replace both solenoids even though only one is leaking, so that is what Gary's did. With 6 solenoids, you must have 3 slides I presume, and perhaps one electric one.
Somewhere I have seen a diagram of which solenoids are which, but unfortunately haven't been able to locate it for you; I will work more on that. You might try the HWH website, or just call them. They were helpful when our incident occurred. It's possible that just carefully snugging the right adjustor nut, using the mut driver on the end of the reservoir cap, will resolve a leaky seal, but I can't attest to that from personal experience. Perhaps others here or at HWH can.
-Joel