Doing a service and all is going smooth as silk until I get to the hyd res filter. I've never replaced it because hydraulics work perfect and I check for water on a regular basis. I pulled the bolts and started to remove the top to R&R the filter. The lid will come up a 1/4 inch and stop - no side to side movement either. Just froze. I broke down and bought a service manual and as with all manuals it does not have a section on unusual circumstances. I also noticed a nail was inserted in the poppet which I had never noticed before. Another thing I discovered was the lid was sealed with permatex which is a big no-no in my book so I know something had gone bad in the past. I'm curious if this problem has been encountered before and any suggestions.