Hi ...I'am not familiar with the F40...with that said......I would do what ever the service manual suggests to ensure the lift arms / lift PISTON never slam/bottom out at the top travel.
When I check the HYD. PSI on my MF FE 35 X I secure lift arms down...see picture:
Install HYD. PSI GAUGE as per picture:
Here's a picture of a lift cover that failed..."YT" Archives....probably due to lift travel out of adjustment,and or relief valve faulty:
With lift arms secured down,as per picture, GAUGE installed,and ENGINE NOT RUNNING...Crank engine on starter with lift control lever in the UP position.
Check HYDRAULIC PSI at point relief Valve relieves.
If gauge indicates a HIGHER PSI than specified as per service manual....I would NOT operate HYDRAULIC system until problem rectified:
Bob...Owner MF FE 35 X