cuziamninja,

The filler plug is close to the top of the reservoir. Access to the filler plug is a bit awkward, but you can do it! Try a syringe (or even a turkey baster). If you can, please take some pics of how you are filling the reservoir, and share them with the forum for future reference...

You are stating that you have the correct fluid already. Just for reference for future readers, I recommend using FeBi 02615 as the most economical and perfectly acceptable fluid. It is identical to Mercedes fluid A0009899103 (aka A 000 989 91 03 10), only the Mercedes fluid has a dye in it. Also acceptable is Pentosin CHF-11S.

As pizzaguy is pointing out, you need to find out where the missing hydraulic fluid has gone. It doesn't evaporate. If the hydraulic fluid level is low, then you have a leak somewhere. Most likely at one of the seven hydraulic cylinders. Usually, the first ones to leak are the main lift cylinders. They typically leak first from the bottom, with fluid coming out of the hole that the mounting pin goes through. The main lift cylinders are easily inspected - just stop the top opening sequence part way when the storage cover (aka tonneau cover) is open. You will see the main lift cylinders far on the side, inside the roadster top storage compartment. Below is a photo of a (right side) main lift cylinder that has just started leaking.



Let us know what you find. If you have a leaking cylinder, send it and at least the matching one on the other side to Top Hydraulics for rebuild/upgrade.
Five of the Crossfire's hydraulic cylinders have straight aluminum bodies, and they all have the same failure mechanism. These five cylinders are:
Right main lift cylinder p/n 5170015AA (located on the right outside bottom of the soft top storage compartment)
Left main lift cylinder p/n 5142639AA (located on the left outside bottom of the soft top storage compartment)
Right bow tension cylinder p/n 5170014AA (located inside the soft top frame, roughly above the right main lift cylinder)
Left bow tension cylinder 5142640AA (located inside the soft top frame, roughly above the left main lift cylinder)
Tonneau cover lift cylinder p/n 5142641AA (shown in the first photo above, next to the hydraulic pump in the trunk.

All of the cylinders above are manufactured the same way, using nearly identical seals. Each one of these cylinders has a number of seals inside: Two cap seals that seal the bottom and top caps/plugs from the cylinder housing, a rod seal that seals the moving shaft/rod from the upper part of the cylinder (specifically, the cap), a wiper seal that keeps debris out of the top cap, a piston seal that seals the piston from the cylinder housing (thus allowing the piston to move under pressure), and two port seals that seal the hydraulic hoses to the cylinder. That's a lot of seals, and Top Hydraulics truly upgrades all of them with better material (and better/larger geometries in case of the wiper, rod seal, and cap seals).

The seals that tend to fail first, are the cap seals. The seals decay with time - it's simply a chemical reaction. That chemical reaction cannot be avoided on the original seals. It gets accelerated with heat and with contamination in the hydraulic fluid. When a bottom cap seal fails, the fluid will actually be coming out of the hole for the mounting pin on the bottom of the cylinder. That's what you are seeing in your photos above. These leaks start slowly, and they will only grow. You need to take care of the problem, or it will only get worse. If you are seeing the leak on one side, then the matching cylinder on the other side will be soon to follow. DIY repair of these cylinders is not feasible. It takes specialized equipment, a lot of know-how, precision machined replacement parts to house the seals, and the right seals.

The two remaining cylinders are:
Rear bow latch cylinder 05142957AA (A1937500184 stamped on it)
Tonneau cover (storage cover) latch cylinder 05166559AA (A1937500183 stamped on it)
These two cylinders will typically fail first at the rod seal, and then at the port seal. Top Hydraulics upgrades rod seals, cap seals, piston seals, and port seals on these cylinders, and we estimate the life expectancy of our seals to be between 30 and 50 years, depending on circumstances.

If you are planning to hang on to your Crossfire for a long time, then it would be wise to have all seven cylinders upgraded in one swoop.

Removal of most of the cylinders is fairly easy.

Klaus

Top Hydraulics | Rebuilt and Upgraded Convertible Top Cylinders, Pumps, Hydraulic Lines - Top Hydraulics, Inc