On our 1845 and 1840 skid steers they both have manual attachment lock levers. The never stay up...you in latch them and lift em up but the just fall down its really a PITA. Is there anything you can do besides not grease the pins...but then it just makes it a PITA to latch em. That why when we got our new 430 we opted for the hydraulic coupler....we are spoiled now with that.
Anyone...i cant be the only one not having this problem. the 430 and 1845 get used the most so its getting annoying having to get out all the time to latch onto a bucket etc when you dont have another person working. It isn't so bad until we grease them up then they just fall. If we dont grease them then its a pain to unlatch em.
I remember having the issue I just cant remember what I did about it. You might try switching to a thick heavy grease, that will keep it lubricated but have enough resistance to hold the levers up.
there are springs in there that need replaced. If its a twin bar quick coupler the part number is 401539A1 https://webparts.pvassociates.net/cnh/main.php for model number enter 1840, select the skid steer, then select the chassis, then look at pages 9-12 thru 9-12b. On page 9-12a number 11 is the spring that I think you should change.
There is a collar between the handle and the coupler that the spring puts tension on to keep the levers in the raise position. There is a ramp/step that will wear over time and let the levers drops. You can replace the collar to get a new ramp on that side of the joint which may help. Alot of time I have replaced the collar and added a couple of washers to the spring to give it more tension in order to keep the levers up.
you may also have worn out bushings in the area were the pins slide try asking the dealership if there are bushings in there if there are 10 -1 there worn out