Failed Hydraulics On IH B414

[Wescountry]

Is there anyone who is able to assist me in troubleshooting the issues with my hydraulic 3pt lift?

Tractor was running at idle with the bush hog elevated, and the bush hog deck lowered to the ground on it's own. I was unable to get it to elevate. The isolator valve is open, since then, the filters have been replaced, and fluid has been changed. The lift did go up without a load on it, but it was very slow. When I stand on the lift arms it wouldn't raise me up, and I'm about 190lbs. After that I replace the hydraulic pump and put new O rings on the isolator valve stem, and the high low flow valve stem. It's still doing the same thing. Without weight on the 3pt lift, I was able to get it to go up and down multiple times thinking this would bleed any air out of the system. And again, it won't go up if I put my weight on it. Any comment would be appreciated.

 

[Fritz Maurer]

Need to check strainer inside reservoir for plugged condition. There are no other filters to replace.
Possibly a stuck relief valve or a broken spring in said valve which is near the fuel tank, to which the power steer lines, if so equipped, attach as well.

The next harder thing to check will be for a blown lift piston seal. They CAN start breaking up and work intermittently.

 

[Wescountry]

Thanks Fritz for your response.
I don't have power steering and it doesn't appear to have a relief valve as shown in the picture. i"ll take a couple of pictures of the tractor and post them tomorrow. the strainer has been replaced. However it does have a valve assembly under the front of the seat. It has an isolator valve and a hi-low flow valve on it. i've ordered a parts manual for this unit, so maybe when I get it I can take a look at it in the exploded view and see if there is a spring in there somewhere.