Loader Float position

[smoothie17]

I have a 2004 B2910 with an LA402 loader with 327 hours. Recently, when I try to put the loader into float it own't engage. I've heard people say the valve probably has some corrosion due to moisture and to take off the end cap and try spraying W-2 40 to free it up. For the life of me I can't figure out where the end cap to the valve is located.

Does anyone have a picture or drawing that might show some detail?

Thanks for your help!