Hi Mike,
Most likely you have a weak breaker. There's a row of 12V DC mini-circuit breakers near the battery. One feeds power to the hydraulic pump. It's a 50 amp auto-reset breaker. If it's weak, it'll trip while operating the hydraulics. Then after a few seconds it automatically resets, allowing the pump to continue. I've attached a picture of the breakers (not the same on every rig). On the bottom, there's a copper buss bar that passes power to all the breakers. You'll also see a thick red wire attached to the bottom of one breaker, with a matching thick wire above. That's the power from the battery to the Power Converter. The other thick wire on top is to the hydraulics pump.
It's also possible that a weak battery could cause the problem. As voltage drops, amp draw goes up. Corrosion or loose battery connections or pump connections could also be a cause. A bind in the slide mechanism could also cause the pump to draw more amps and trip the breaker. But the breaker is usually the problem. Costs $5-10 and takes 15 minutes to replace. Just make sure you get one with the same form factor so it fits in place of the original.
Here's a link to one on Amazon. You can also usually find them at local auto or marine parts stores.