Steiner 430 Hydraulic question

[JumboShrimp]

Hi All
I have a 430 that I bought used. I put an aerator on the front and that's all I use it for. Lately, the lever that controls the front lift won't stay in 'float' - and it needs to. Once it pops out of float it starts to slowly raise the front wheels off the ground.
I know zero about hydraulic valving and was wondering if anyone knows a way to adjust the detent on that lever. I looked at it and there is no 'obvious' adjustment on it
Thanks for any help