Changing Hydraulic Fluid

You can buy MIL-H-5606A from also from aircraft spruce and specialty, they have good online stores and prices are reasonable. It has been around a long time and is still used. If you can’t find it under the mil spec you can find it often as Royco 756. It is a mineral based oil. It will eat rubber that is not “spec”ed for exposure to this type of fluid.
I accidentally dropped something on the hydraulic line that runs from the Passenger side back to the pump and created a small cut in the line that caused it to lose pressure--I heard fluid leaking back into the reservoirs. I've changed the broken line but I lost around a quarter of a cup of fluid in the process. My camper has been in the up position resting on the pins for several months.

The instructions that came with the camper said that you should lower the camper before adding more fluid but I can't raise the camper up off the pins. I tried bleeding the system by running the pump for 15 seconds with the gate valve in the open (or lowering) position.

Should I try putting some fluid into the reservoir or will fluid go all over the place if I unscrew the fill cap with the camper in the up position?

I would appreciate any thoughts on the best steps to proceed?

If you have cable jacks, can you raise the top with them gently? I think I read that on a fb AC forum as a solution, to get the pins pulled?
If the camper is in the raised position, the fluid will be in the rams, not the reservoir. When in the lowered position the rams are compressed and the fluid is in the reservoir. You could add a small amounts of fluid in the raised position operating the pump after each add until it reacts and comes off the pins. Then lower it and fill to full level.
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