Cub Cadet 1250 hydraulic leak

[NCShelton]

I have a 1250 Cub Cadet with hydrostatic drive. I recently changed the hydraulic oil filter and refilled the reservoir with hydraulic fluid unitl fluid leaked out the fill hole at the rear of the mower. Now, oil leaks through the vent holes at the top of the assembly above the filter when the Cub is in motion - i.e., the hydrostatic drive is operating. What has happened? Today, I refilled it until the fluid ran out the fill hole, and it held over a quart!!! The closer to full it is, the faster the oil comes out the vent when the Cub is in motion. One solution is to run it low on oil so it won't run out the vent. However, I don't think this would be very good for the hydrostatic drive. Does anyone have any suggestions as to what the problem is?

Thanks

 

[Bob_Bainbridge]

There are 2 check valves on top of the transmission with small vent holes in them. If this is where your oil is leaking, one of the valves may have a piece of dirt in it or be stuck. I ended up replacing one of the valves on a 1450 for leakage. Another leak point is the gasket seal between the transmission and differential. This causes oil to drip off the pipe behind the filter.

Bob B.

 

[Theowegian]

I too have a 1250 Cub Cadet.

I think the oil capacity is 7 quarts or so in the hydro.

You might take out those two check valves on top of the hydro and check for dirt and free movement.

dwight

 

[NCShelton]

UpDate on leaking vent valves. I removed and cleaned the vent valves, but one did not seal off. Changed positions (left to right, right to left), and the same one leaked in both positions. Purchased new check valve, and replacement o-rings and washer for the other one, from Hickory Home and Garden Center. Fixed it right up.

Thanks to everyone who offered suggestions.