good evening
I attached the hydatic diagram for your YALE truck as you can see there are two hydraulic filters one in the hydraulic oil tank neck which is filter NO.7
the other filter is NO.8 in the hydraulic suction line.
You must check these two filters.
also you must check suction hose NO.33 which maybe leaking or damage.
If your problem still present then hydraulic pump NO.55 need to change
This is ONLY to be used to report flooding, spam, advertising and problematic (harassing, abusive or crude) posts.