I have a 52 8N with a Sherman Hi/Lo. The hydraulics were rebuilt a couple years ago and work well with one exception. Occasionally while lifting an implement (usually my 5 ft box scraper) from the ground with the hydraulic handle in the full up position and the scraper traveling upwards, the handle will sometimes slide back down causing the implement to stop lifting or lower again. I have managed to catch it every time so far. The lever doesn’t seem to have much tension when moved up/down or securely stay in the up position during transport. Is there any way to put any more friction on the lever or is this an indication of a mechanical hydraulic issue? Thanks!