HST Wont move forward or back

[Jabonee]

If memory serves me I believe there is a tiny little orifice in that HST servo valve. It may be getting plugged with dirt floating back and forth. That would explain the intermittent issue. :confused3:

 

[johnny787]

If memory serves me I believe there is a tiny little orifice in that HST servo valve. It may be getting plugged with dirt floating back and forth. That would explain the intermittent issue. :confused3:

How would I go about accessing this piece?

 

[RNeumann]

After the last debacle I’d still vote for a systematic approach starting with the basics. Safety/Lockouts, linkage adjustments, fluid levels etc. Then move to wiring/connections, external parts on the case (their aren’t many) etc. Last resort is obviously cracking the case.
If history is the guide, your dealer’s strong suit isn’t diagnosis. Maybe a private equipment mechanic is in order.

 

[Makers_Mark]

Uhg. I'm reviving this post since it just happened to my "new to me" 2015 Mahindra 2555. Same exact issues. Tractor has been great for the almost 2 years I've had it. Worked fine all day. Powerwashed and parked it. Next morning the issues started. I thought I had gotten water in something but 3 days later and oil and filter changes, still the same. Works for a few hours then stops. If I hold down either pedal for a while, it will try and creep but struggles. FEL and rear lift work fine.
All the posts I've read just end with no resolution. I know it's 4 years later but did anyone resolve this?
Haven't called the dealer since his response will be to bring it in and I won't see my tractor for 4-6 months.

 

[Sergei1]

Uhg. I'm reviving this post since it just happened to my "new to me" 2015 Mahindra 2555. Same exact issues. Tractor has been great for the almost 2 years I've had it. Worked fine all day. Powerwashed and parked it. Next morning the issues started. I thought I had gotten water in something but 3 days later and oil and filter changes, still the same. Works for a few hours then stops. If I hold down either pedal for a while, it will try and creep but struggles. FEL and rear lift work fine.
All the posts I've read just end with no resolution. I know it's 4 years later but did anyone resolve this?
Haven't called the dealer since his response will be to bring it in and I won't see my tractor for 4-6 months.

Sounding like you may have lost hydraulic charge pressure to the transmission. I’m assuming your tractor is HST and probably has two pumps like my 2815 or a single pump with dual purpose. Does the steering work correctly
Looking a Mahindra site your tractor uses a single pump with a 19.5cc output which would be for the FEL and 3 point and a 8 cc output for steering and transmission charge.

 

[Makers_Mark]

Thanks for response Sergei. Sorry, responding so late. Yes hst and yes steering works. Ruled out all the simple things like rim rotation, remote lever in open position, clogged filters, bad oil, etc.
I unplugged and cleaned the pedal switches under the floorboard too. I was really hoping it was the power washing that caused the problem but it's been days now. Called two dealers and both of course said never experienced the problem and to bring it in. Just wanted to try everything I can before shelling out dough needlessly.

 

[duffer]

According to the OP, the solution was the "power beyond" (or remote hydro) was engaged, causing a loss of flow to HST. On my model, the 3 pt hydro flows thru my FEL control valve, thru a power beyond port with a special fitting.

Perhaps your HST does to if you only have 1 hydro pump. (sorry not familiar with your exact model).

Anyway, I'd remove the port fittings,(not just the quick connects) clean them, blow out the female ports, and reinstall. Who knows, you might get lucky. Doesn't cost anything. Just be sure to release the pressure on the control valve first.

 

[Sergei1]

Thanks for response Sergei. Sorry, responding so late. Yes hst and yes steering works. Ruled out all the simple things like rim rotation, remote lever in open position, clogged filters, bad oil, etc.
I unplugged and cleaned the pedal switches under the floorboard too. I was really hoping it was the power washing that caused the problem but it's been days now. Called two dealers and both of course said never experienced the problem and to bring it in. Just wanted to try everything I can before shelling out dough needlessly.

Have you checked the HST linkage for being loose like missing bolt from the trunnion arm or not tight. How many hours does the tractor have? Also the steering doesn't jerk when turned left or right?

 

[Makers_Mark]

Most likely 2 pumps since fel and rear hydro are working perfectly. I ordered a manual so I could at least understand the flow of the hydro drive. I feel like I've tried all I know at this point. I know there may be a hydraulic controller behind dash but if it's a sealed unit what can I actually test? And of course, if there's a separate pump for the drive, that could have went.
Tractor has about 850 hrs and the steering is smooth. If I get in the tractor while it's been sitting overnight or for some time, the tractor seems to move normally, but within seconds or a minute, it loses power...as if it lost pressure...but only in the drive system.
I see a relief valve but it's for the overall hydro, not specific to the drive. I may break down and take it to dealer next week since I need it... especially with winter coming.

 

[Sergei1]

You might look for a previous posting on this sites tiled "Mahindra 2555 HST won't go forward" which was dated Nov19, 2017. Also found other posting which seems to point to electrical connector plug as being the issue. Seems that a lot of people have had your problem and some have found possible fixes.
Found the post under General Tractor Topics then Parts/Repair, search the posts. Regular search doesn’t really help.