Hello, New to the forum. How are all doing? Long live Oliver tractors.

I have some 1250 questions. 

Hydraulic Fluid. Where to add? What type of fluid? 

 Went to plow snow the other day and it makes a nasty whining sound when lifting 3 point up. Have had this tractor for a few years and this is the first winter it has done this.
 Knock on wood, This tractor has been good to me and a workhorse for $1300. I love the old girl.

I have a manual but it does not give this info. Just tells capacities. 

Thank you, Mike