I have a little B4200 which has been great over the years. I noticed recently that the lowering lever for the FEL is very binary e.g. very difficult to lower slowly. I thought I would systematically run through the hydraulic system and check it but I am having problems in identifying if it has a filter for the hydraulic system and if so where it is. Can anyone help me identify the filter and how to check it? Kind regards, Dave.