Great Dane Hydro Question

[gibsonsg311]

I have a 36" great dane and the hydros seem to make alot more noise than when i first bought it. I haven't had time to go to my dealer which is about 14 miles from my house. I was wondering if there was any maintenance i should be performing.
The hydro pumps are intergrated and their doesn't seem to be a fill valve to drop any oil into.
Any replies are greatly appreciated. Thanks, John

[jpiwowar]

have the dealer check it before it is too late