Hello guys, A rancher friend of mine called me and asked me to come out and take a look at his D6C. He was pushing a path through the snow out into his hay meadows so he could feed his cows. He worked the machine for about 45 minutes and made one final push forward. Once he put it into reverse he lost all blade hydraulics. (up, down, tilt, etc) I have never worked on a D6C. Does anyone have experience working on these that might get me pointed in the right direction other than checking the simple stuff. It has been cold here for a couple of days. I can't help but think its iced up somewhere, like a filter or bottom of the reservior. Dozer still moves fine but if he goes forward he starts to move dirt. He plans on driving it in reverse about a mile to get it back to his shop where he can let it thaw for a while. Thanks in advance for any help you guys can provide.

Your thinking it's ice is probably correct.
Can you get a model # for the tractor and # off the hydraulic tank?

OM, I plan on going over there tomorrow. I will post that info when I get back. Thanks for the help.

Take the filter cover off and crank the engine over a bit to see if any oil is moving. Be carefull not to start engine. Might have broken a pump shaft or split a rotor.
Later Bob