Aaahhhhh! 1250 hydro not moving

[ajplacke]

drained and replaced fluid and filter. released relief valves, they move freely. when i start the engine and push hydro lever to reverse it gives out that classic hydro hum but won't move. when i push the lever to forward theres no hum and definitely no forward. when i pulled out the fill plug the fluid is frothy. when i took the diff plate off to drain fluid one of the bolts is stripped out and only snug to maybe 2-5 ft lbs. can that cause an air leak and give me the no go? just wondering if there is anything else i'm missing? getting frustrated

[finsruskw]

sounds like a priming issue.
Did you install the correct filter?

[ajplacke]

there was a PH 710 on it and i replaced it with the napa gold 1410

[Billy-O]

Curiously.... Is this a new problem that developed after the filter/ oil change OR you were trying to remedy the problem with oil /filter change?

If new,....The right oil? Enough oil? Filter on tight?

If old, no broken/missing pins on the driveshaft? There is front and back!

[ol'George]

Foam in the oil is not the norm.
sounds possibly the filter is not tight.

After it sets for a few hours or over night, does it still malfunction?
We are assuming you cleaned out the rear when you had the cover off?
The differential/reservoir in not air tight, and a stripped bolt will most likely leak but cause no operational problems.
Sometimes after a filter change or prolonged no usage (like a year or more) they need a gentle shot with an air hose in the fill plug hole to prime the system.
Now I'm talking a rag wrapped around the air hose, just a few pounds at most, not full pressure from the compressor!
let us know the answers we asked.
Also are you sure the release valves are popped back up after you pushed them up/down?
The last thing I'd suggest if no joy with mentioned advice is to swap the release valves side for side and see if the no wine/hum goes to the other direction, that would suggest a stuck relief valve.

[ajplacke]

Both spiral pins are good. the fluid was completely drained and everything wiped out. replaced fluid with tractor supply Traveller premium trans/hydro fluid and the NAPA gold 1410 filter. relief valves are popped up and the ball bearing moves freely in both. i did flop them and similar result, it hums like it wants to go when putting lever in reverse, no hum when moved to forward. the tractor has been sitting for Lord knows how many years at the previous owners and now I'm trying to resurrect this thing. i will try the pressurizing

[dodge trucker]

sounds air locked. did you try and put any fluid in the filter before it got screwed on? Yeah its tough, you certainly won't be able to get it "full" as it will tend to want to spill out to the bottom of the hole when spun on.... I have had other machines with the same hydro setup (Sunstrand 15) that have been a pain to bleed upon a fluid and filter swap.

[ajplacke]

yup i had the filter as full as possible b4 screwing on. still havent pressurized it yet (pulled the engine on my '79 bronco sunday😃, squirrel!)

[ajplacke]

i charged the trans with compressed air. still not moving. interestingly, the left valve nipple is now sticking. when i took the fill plug off there was a pretty good release of air, like a bunch of pressure built up in the case. any ideas where to go next?

[ol'George]

if you are getting air pressure in the reservoir you have to be sucking it in somewhere.
the suction line is under the oil level so it shouldn't happen.
is the nut tight on the suction tube on the bottom of the hydro ( it is by the side of the filter and goes into the front of the rear housing at the bottom).