MF150 Hydraulic issues

Hi all,

I'm having some issues with the 3 point lift on my new to me MF150. A couple weeks ago I changed the hydraulic fluid in the tractor. I noticed a few issues:

1. Old fluid was milky.
2. Only about 6 gallons of fluid came out (manual says it takes 8 gallons), I drained both front and rear drains.
3. I put 6 gallons of Traveller UTF back in, dipstick read full.

It worked fine after changing the fluid. I mounted the snowblower a week later and it worked fine. The other night it snowed and it was really cold out. 3 point Lift was acting real jerky going up and it wouldn't go all the way up, it would only barely lift the snowblower off the ground. Temperature was in the teens that night.

Today it is unseasonably warm out, in the 50's so I tried the lift again. It still went up jerky but it would lift the snowblower all the way up. I checked the hydraulic fluid and it's back to being milky again even though I just changed it.

Any help would be greatly appreciated. Here's my questions:

1. Did I miss something? I'm wondering why only 6 gallons came out when it's supposed to hold 8. I'm guessing that if there was still 2 gallons of milky hydraulic fluid in there that I didn't get out that's why the new fluid is milky looking. Previous owner had it sitting outside all summer. I've had it under a tarp since I changed the hydraulic fluid (a pole barn is in the plans for next summer).

2. Is it possible that my dipstick is off somehow? I'm thinking maybe it was low to begin with and is still low which also might cause erratic operation.

Might be the wrong dipstick, oil SHOULD come out the lower six bolt cover hole if it's truly full. Still sounds like there's some water in the system, it can be hard to get rid of in cooler weather.

Pulling the PTO shaft out will let you flush out the rear end with diesel . There can be an amazing amount of sediment lodged behing the pump and around the PTO seal ,. One way to be certain it's clean .

(quoted from post at 15:08:47 01/11/20) Might be the wrong dipstick, oil SHOULD come out the lower six bolt cover hole if it's truly full. Still sounds like there's some water in the system, it can be hard to get rid of in cooler weather.

Click to expand...

Ok so I should be able to pull that bolt and fill until fluid comes out?

(quoted from post at 15:54:04 01/11/20)
Pulling the PTO shaft out will let you flush out the rear end with diesel . There can be an amazing amount of sediment lodged behing the pump and around the PTO seal ,. One way to be certain it's clean .

Click to expand...

Ok just so I understand correctly do you pull the PTO shaft in order to pour diesel in through that direction?

Remove the side plate , either one will do but the dip stick side is easier , use a sprayer or some such to wash the inside of the casing down . Once the shaft is out you can just about get most of your fingers in there to scrape out the worst of the sediment . Flush out again , through the side cover hole, by pouring a litre or two once you've done that . Collect the diesel as it pours out and let it settle before reusing it a few times . Once most of the grit is out use some fresh clean stuff for a final rinse .
I used a leaf blowing machine to get the last of the diesel residue out before refilling with new oil .
Side cover gasket is easy to cut yourself if you need one , use some thin card , a cereal box is ideal , there is no pressure in that part of the machine

Upon closer inspection today it appears that the hydraulic fluid is actually foamy looking (small air bubbles throughout fluid). When I first checked the dipstick it was clear then after running it the fluid has tons of small air bubbles everywhere. What does that indicate?