A lot of questions so I'll try and work through them one at a time. $2500 would equate to around £1650 for us. That's one huge amount of money.
What did you have done to justify that price?
Lift arms not falling and needing weight to push them down.
Lift the lift arms by hand. They should be perfectly free to lift and fall again under their own weight. At the end of the main top shaft is a bolt held with a tabwasher. The RH bolt should be fully tightened and tabbed. The LH bolt should be adjusted so that the lift arms drop under their own weight. Has this bolt been over-tightend perhaps in an attempt to disguise wear in the bushes or on the shaft?
The Response lever will not affect the speed of the lift. The operation of it is self priming. Providing that it has been adjusted correctly, if set to 'Fast' the arms should fall normally.
Loss of pressure at the 3-point and remotes may have been due to a blocked filter/s. Depending on the type of pump fitted it may have been necessary to split the tractor between the gearbox and centre casing to gain access to the aux filter. Does this tractor have an Independant pto?
From the symptoms that you describe the slow lift and fall could be due to incorrect adjustment of the internal linkage. What may be happening is that the lever on the pump which controls the raise, neutral and drop positions is not responding correctly to the commands given by the Position Control lever at the quadrant.
Is this repairer a MF franchised dealer? Do they have the special MF tools and experienced staff to carry out repairs of this sort? Whilst hydraulic overhaul is not a 'computer' job it does require experience.
Do you have a written description of the work done? I and I'm sure that meny reading this would be interested in seeing how the final figure was arrived at.
If the raise and lower speeds are not correct and you have to 'jump' on the 3-point to lower it then this clearly is not correct.
I would suggest that you get on the phone to the person in charge and bend his/her ear big-time about how much you have paid for a repair which is effectively useless. Off my soapbox now!
Please let us know as much as you can about the bill and how you get on.
DavidP, South Wales.