How to install a 3 point hitch on a 140 farmall did not come with a 3 point hitch

https://www.redpowermagazine.com/forums/topic/93705-farmall-newby-needs-help-with-806-hydraulics/
https://talk.newagtalk.com/forums/thread-view.asp?tid=571997&DisplayType=flat&setCookie=1
If it was working before you changed the filter it may have air in lines or pump

ck to see what hydraulic oil your using , I bet it's an all weather rated oil, if temp is below zero then that's out of "all weather" range , you will need to look into using a cold weather rated oil (ck with you local dealer to ask ), my tractor has an oil bypass lever you can engage on the valve block this allows oil to circulate around in loop to heat up (+20 degrees) to work in cold temps , I don't think a 856 has one of them

Is the draft levers in right postion

You broke linkage inside on rockshaft when you pulled off the right lift arm. Sorry. Pull top hitch off and repair. There is a procedure to replace these seals safely without moving rockshaft side to side.

1966 TractorData com Farmall 140 tractor information

The point gap should be 0.013 inches. You should also check the end play and run out on the shaft before point installation (vertical & horizontal movement)- should be minimal or the engine will run erratic or not at all if too loose.

could be a bad battery or the alternator...I would think...try swapping batteries from the car you are boosting from...if it still fails..then the alternator is bad...I would think...

if all tie rods are tight the steering box has a philips screw with a jam nut loose nut turn screw in until it stops, back out a little tighten jam nut. that takes slack out of worm gear. hope this helps

yes it is correct it is just the way it is

FOUND YOU A WEB SITE FOR WIRING DIAGRAM
CARTER & GRUENEWALD CO. INC.
IF THAT DOSN'T WORK LOOK UNDER FARMALL 140 WIRING DIAGRAMS AND THE SITE WILL BE LISTED THIS SITE WON'T LET ME COPY AND PASTE TO YOU