loader problems

[toad270]

My brother called me today said he was having problems with My Dads loader on A/C 720 loader model 700 it wouldn't raise the bucket when it was full but would when empty he put his hand on the cylinders and three of the four was warm to the touch the fourth was cold. Does anyone have any idea what would cause this problem? Is there any diagrams of the loader on the site? I couldn't find a model number for the 720

[cranemech]

Afternoon, Sounds like the packing in the cylinders could possibly be bad and allowing the fluid to bypass. When the hydraulic fluid leaks by the seal it causes heat. Is the reservoir hot or cold. Lifting is accomplished by pressure. You are losing pressure either in the valve bank, relief valve or your pump. The cylinders being warm leads me to suspect the cylinders. Does the loader bleed down with a load? These cylinders are very easy to reseal just an o-ring and possibly a back-up ring. Later, Chad

[toad270]

my dad said the reservoir was warm and he is just going to have the pump and cylinders rebuilt Thanks for the help Herbert But i would still like to know the model no for the 720 and hopefully diagram for the loader