# Case IH STX 335



## Walter Boss (Oct 4, 2017)

2009 stx 335 stieger with 2600 hrs.. It loses transmission pressure when hot.
I checked every thing I can think of.
Hope someone can give me fresh Ideas


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## sixbales (May 18, 2011)

Howdy Walter, welcome to the tractor forum.

First thing I would check is your pressure sensor. The computer relies on this sensor. Can you put a pressure gauge on it? I think the pressure should be about 250 psi.

I copied the following post on the internet regarding an STX: "we ended up putting a shim in the valve spring. Had a washer that fit perfect. It was about .015 to .020 thick. Took the pressure from 275 to 305 psi. No more issues."

Good Luck.


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## Walter Boss (Oct 4, 2017)

Thank you sixbales, Gonna take some getting used to this site. I did install a manual gauge next to the sensor & they read the same. I also hooked a battery charger on low setting to the coil. It had good pull but didn't change pressure. I will follow up on the shims even the diagnostics says not to. I changed all the springs. I will need a bit of luck. I know there are some very smart people out there. Thought I would get more response maybe I'm doing something wrong.


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## RC Wells (Dec 26, 2008)

This may be pertinent, or not, I had a field tech hook the motor case drain to the tractor pressure return, and the planter motor pressure return to the direct dump port on the tractor. Transmission functioned until the oil temp reached 240 F, and then transmission lost all pressure. Steiger 535 16 speed power shift. Lost half a day until the lines from the planter were correctly attached and the regulator valve assembly replaced. 

Had something to do with pressure buildup in the pressure return on the tractor that stuck the main pilot spool so it failed to fully switch. Once the lines were sorted the problem went away along with my old regulator valve assembly and a pile of money. The Steiger tech mentioned this would also occur if the regulator valve got a sticky spool from wear or contaminated oil.


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