Wheel does not go hard over

Wondering if I could get some advice here. I have a older model Tiara with twin inboards and Teleflex Seastar hydraulic steering. Previously I was able to go hard-over on the wheel, both to port and starboard. Now for some unknown reason I can just keep turning the wheel with no hard-over. I'm thinking that the system might need to be blead of air but I don't see any bubbles in the line. I also see red colored fluid in the hydraulic lines, because it's red I'm wondering if it's tranny fluid and not the approved Seastar fluid. At the helm pump I see the fill but I'm unsure if the fluid is just too low. I was going to add to it but I didn't want to add the Seastar fluid which is clear to the red fluid already in the lines. So, my questions are - is this issue caused by air in the lines and it needs to be blead or is the fluid simply just too low but can I mix fluids or do I have to do a full flush of the system? I do not see any leaks in the bilge either. The wheel does not seem to feel sluggish and I do not feel any bumps or skips when turnng it. I do think it's kind of slow to respond when under-way but that might just be me. Any thoughts here? Bleed the system? Replace all the fluid? Mix fluids? Something else I might be missing??

Any help would be appreciated!
thanks