Changed T1400 HST fluid now it won't move

fruitcakesa

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Equipment
M 6040
Oct 26, 2010
852
265
63
Cavendish Vermont
Are you saying that you put 10w30 engine oil in the hydrostat unit? If so, you screwed the pooch.
This is the recommended fluid for the HST according to the manual I saw online.
From the manual:
Hydrostatic Transmission 0.60 US qts. (0.57 L) API service CD SAE 10w-30

Transmission Case - T1400H 1.9 US qts. (1.8 L)
- T1400 2.7 US qts. (2.6 L)
-------------------------------------------------------------------------------------
Multi-grade trasnmission fluid or gear oil SAE #90. The fluid listed below or equivelent are recommended.
Kubota - UDT Hydrostatic transmission fluid
Shell - Donax-TD Donax-TM
Mobil - Mobil Fluid 350, 423
Exxon - Torque Fluid 56
 
Last edited:

Dave_eng

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M7040, Nuffield 465
Oct 6, 2012
5,108
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Williamstown Ontario Canada
Most hydrostat tractors have a small lever to disengage the drive so you can move it with the engine off.

Make certain yours is in the proper position

The attached is from a T1880 but your will have something similar

Dave
 

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fruitcakesa

Well-known member

Equipment
M 6040
Oct 26, 2010
852
265
63
Cavendish Vermont
Most hydrostat tractors have a small lever to disengage the drive so you can move it with the engine off.

Make certain yours is in the proper position

The attached is from a T1880 but your will have something similar

Dave
I know that lever, it is under the seat and was functional till now.
The tractor now will roll without using the lever. It appears to have been affected by whatever this is too.
 

RCW

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BX2360, FEL, MMM, BX2750D snowblower. 1953 Minneapolis Moline ZAU
Apr 28, 2013
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Fruitcake -

I sincerely hope you find the gobblin that is stalking your tractor.

Honestly, when I saw the 10w-30 for the HST, I thought it's "cooked", just like rentthis concluded.

Glad to see it's apparently called for, and you get it going!

Best wishes!

Sent from my QTASUN1 using Tapatalk
 

Dwarner

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B7610 HST, Woods 6500
Aug 3, 2012
114
4
18
Enfield, CT
I have had this problem on other hydrostst equipment. The issue was an air bound pump. To purge the air we engaged the drive forward and reverse while the engine is running with the tires raised off the ground. In a few minutes the power came back.
 

Fordtech86

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L3200
Aug 7, 2018
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Pineville,LA
I have had this problem on other hydrostst equipment. The issue was an air bound pump. To purge the air we engaged the drive forward and reverse while the engine is running with the tires raised off the ground. In a few minutes the power came back.
My thoughts too, it’s air locked. I’ve had the same issue with my case 224. Keep the wheels off the ground and cycle it to try to purge it out.
 

Pau7220

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L3650 GST, Landpride TL250 FEL w/ Piranha, 6' King Kutter, GM1084R Finish
Aug 1, 2017
785
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Scranton, PA
My thoughts too, it’s air locked. I’ve had the same issue with my case 224. Keep the wheels off the ground and cycle it to try to purge it out.
My Honda 4120 also specs 10w-30. Manual specifically states not to use hydrostatic fluid (as the older ones did). It is also a SOB to get reprimed. Manual states engine at medium speed, gently move between forward and reverse, taking care not to go past halfway with control. Just when it sounds like it's gonna explode, it starts working normally.
 

SidecarFlip

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M9000HDCC3, M9000HD, Kubota GS850 Sidekick
Oct 28, 2018
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Hydro Gear transmissions take multi grade engine oil. If yours has filters change them too. Hydro Gear sells a nifty change kit that eliminates the tedious filling. It comes with a fitting that fits in the uppermost plug in the transaxle and a pump to pump the oil in and the pump and fitting are reuseable so it's a one time buy... That is if you have Hydro Gear transmissions.
 

fruitcakesa

Well-known member

Equipment
M 6040
Oct 26, 2010
852
265
63
Cavendish Vermont
Jacked it up and ran it while moving the hydro pedal F&R.
About a minute or so later, the wheels began to turn so I continued rocking the pedal for another minute and voila, it was fixed:D.
I also shortened the HST pedal adjuster 2 turns and now it is better than before I did the change.
Thanks again for the tips.
 

Gillie Dog

Member

Equipment
L2501 HST, FEL, Forks Attachment, Harrow Disc, etc.
Dec 12, 2018
79
2
6
Southern California
Sorry, I wasn't thinking lawn mower.
No issue. OP had it covered anyway.

I knew only because, when I worked for a living, my landscaping department had several of these type of mowers and they used engine oil in HSTs also for some unknown reason.

GD
 

fruitcakesa

Well-known member

Equipment
M 6040
Oct 26, 2010
852
265
63
Cavendish Vermont
update:
Took it out mowing and after about 15 minutes , the tractor stopped moving with almost no HST pedal engagement.
I was able to limp it back to the shop and re-readjusted pedal travel which changed nothing.
I jacked it up and ran it while rocking the pedal and lo and behold, it started working again.
So, did I not get all the air out the first time? Why did it runs so well for 15 minutes.
Does anyone know the pedal adjustment and spec? I am just guessing when I do it.
The actual pedal is sloppy on the shaft maybe 1/8 to 1/4 inch play.
I tried to account for that when I made the adjustment.
Would an old belt cause this? I changed it years ago.
I will see what happens in the meantime.
 

Fordtech86

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L3200
Aug 7, 2018
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Pineville,LA
I would guess you didn’t get it all bled out. I would have ran it on jack stands for a while when bleeding it even after it started going (and maybe you did?) Also did you double check level after? As far as belt goes check tensioner too, unsure how it’s set up on that particular mower. Typically if it’s slipping though you would smell burnt rubber I would think.