MF135 slow loader movement

[HoosierMuscle]

I have a 1973 gas 135 with a Kelly loader. Hadn’t used it in months. Jumped on it over the weekend and noticed the loader was moving very slow. I finished the small task I had and went to put it away. At that point the loader wouldn’t raise at all and when switching the valve to the 3 point lift, it also wouldn’t move. I noticed the oil level was just over Low so I added some and no change. I let it sit overnight then pulled the valve on the top cover to see if possibly the tube had come undone. When I pulled the valve, oil came out the top and went everywhere. O ring looked good so reassembled. Started tractor and the loader would move again but was slow.

Ideas? I’ve never had the top cover off or messed with the hydraulics.

 

[Ray,IN]

Possibly junk in relief valve holding it partially open? When was the transmission oil last changed? If never, there can be water in the bottom of the case causing problems.

 

[HoosierMuscle]

I changed it a couple years ago, but just a drain and refill. I am just seeing now that there is a filter inside. The tractor is only used a handful of times per year. Where would I find the relief valve?

 

[Ray,IN]

This thread is better than my explanation: https://forums.yesterdaystractors.com/threads/mf-135-hydraulic-relief-valve.1098715/