Finally got my WDrunning but hydraulics don't work right. It won't raise till the lever is about 80% up then it raises all the way. Then the it lowers at the same position but all the way down. No stopping anywhere in between. I have turned both the knobs on the pump with no change. I did move the lever linked to the draft control and it raised the arms but it also raised them all the way after letting go it lowered all the way back. Also, if I clean the valve, do I replace anything or just clean it? Any help would be appreciated.