1512 a no go

[Loader]

One of my Cub Cadet tractors is a 1512. For those unfamiliar, this is a wide frame diesel with a grille like a 682, 782 and is just a newer version of the 782D or 882, but it is not a Super GT like a 982, 1572, or 1772. It's a CCC unit with the aluminum rear. The 15HP Kubota diesel makes this one hard working unit!

Now the stupid human act and what I need help with.

I had it parked on a hill with a trailer behind it, brake on. I was loading the trailer with heavy soil. The tractor was creeping, so I thought the trans must be out of adjustment (my 1450 used to walk away until I learns how to adjust the linkage) and so bumped the lever forward a little until it stopped creeping.

Well, that lasted for a little bit. I had to tend to something else and when I returned the tractor and trailer were down in the trees. I figured it crept there. So, I hopped on and threw the lever forward and -nothing. No movement at all. No forward, no reverse as if there were no hydraulic pressure at all.

After I got it disconnected from the trailer and out from the pine tree, I realized it would roll with little resistance.

Did I blow the hydraulic pump? Or maybe I just burned up the trans fluid? I do have a new fan on the pump shaft, so it should've had air, but maybe not enough if I had actually been using the transmission as a brake to help hold it on the hill.

What do you think - about what could be wrong with the tractor, not my bone-headed move.

Thanks!

[CubDieselFan]

First of all welcome to Only Cub Cadets. It sounds like you broke a spiral pin where the drive shaft connects to the hydro pump shaft. Does the hydraulic lift work?

[J-Mech]

We all are very familiar with Cub Cadets, so a model number will do fine. But thanks for the description. Much better than most!!

Yeah, CubDieselFan is right on. Sounds like the pin broke or fell out. You didn't do anything wrong at all. It won't overheat just sitting idling and as long as it's running and not rolling no need to set the brake. If the trees were down hill, I'd say it rolled not crept.

[Loader]

Originally Posted by CubDieselFan

First of all welcome to Only Cub Cadets. It sounds like you broke a spiral pin where the drive shaft connects to the hydro pump shaft. Does the hydraulic lift work?

No. No hydraulics at all. Nothing is visually wrong. Drive shaft and all roll pins are intact. So, the pump is being spun, but no longer pumping.

[Loader]

Originally Posted by J-Mech

We all are very familiar with Cub Cadets, so a model number will do fine. But thanks for the description. Much better than most!!

Yeah, CubDieselFan is right on. Sounds like the pin broke or fell out. You didn't do anything wrong at all. It won't overheat just sitting idling and as long as it's running and not rolling no need to set the brake. If the trees were down hill, I'd say it rolled not crept.

That's what I was hoping! I know the difference between a narrow and wide frame, but certainly don't know how to trouble shoot!

If you're referring to the roll pin in the pump shaft, that is intact.

Yes, it was on a hill (driveway) pointed uphill, trailer behind. The heavier the trailer got, the more it crept. I bumped the forward control to hold it on the hill because the brakes weren't doing it. All was fine until it apparently lost hydraulic pressure and rolled down into the trees where it just sat there idling and waiting for me.

I just drained the fluid, but it looked fine and didn't smell burnt. I don't know if I should flush the lines, refill, and see if it will start to pump again or just get another pump. Or, maybe it's something else.

[Oak]

It may look intact but I'm still thinking its broke. Can you push something through it or just remove it?

[J-Mech]

Originally Posted by Oak

It may look intact but I'm still thinking its broke. Can you push something through it or just remove it?

Agreed. It will look intact, even if it's broken.

Note:
(This is an informational note, not directed to the OP. It's for everyone.)

Hydrostat transmissions aren't automatics. There are no clutches to burn up. Everyone always talks about the fluid not smelling burnt. There really is no way for it to burn, scorch, or even get very hot. Oh sure it can, but it's rare. Very rare. It's not like in an automatic when the clutches start to slip and literally cook the oil that they are soaked in. This is just a piston pump. Everything would have to happen just right to burn the oil. Case would have to be covered in dirt, no fan, oil ran low and worked to the hilt. Even then.... it may not smell burnt.

[Loader]

Originally Posted by J-Mech

Agreed. It will look intact, even if it's broken.

Note:
(This is an informational note, not directed to the OP. It's for everyone.)

Hydrostat transmissions aren't automatics. There are no clutches to burn up. Everyone always talks about the fluid not smelling burnt. There really is no way for it to burn, scorch, or even get very hot. Oh sure it can, but it's rare. Very rare. It's not like in an automatic when the clutches start to slip and literally cook the oil that they are soaked in. This is just a piston pump. Everything would have to happen just right to burn the oil. Case would have to be covered in dirt, no fan, oil ran low and worked to the hilt. Even then.... it may not smell burnt.

Interesting. Well, what I did was turn the shaft and I could see the pump shaft turning, so I assumed the pin was fine. I put new pins in a couple of years ago when I redid the shaft with a new fan and double rag joints to reduce vibration.

I'll punch the pins out and inspect then this weekend.

[Sam Mac]

If this was my tractor I’d verify that the pump shaft is turning with the engine running before changing the pins. If the shaft is turning then something else is wrong. Possibilities include, plugged filter, plugged suction line, bad charge pump, sucking air at the suction line or charge pump seal, check valve, relief valve. If you have Hy-Tran in it maybe a glob of the waxy stuff it forms from water blocked or plugged the filter. You are sure it has enough oil in it. Just tossing out other possibilities for you to consider.

[Billy-O]

I'd, too, would verify the pin is good before getting into anything else. Just as Sam Mac pointed out. I was curious, just how steep was that hill your tractor rolled down? I was thinking perhaps suction lines exposed to air or something unsettled from gravity orientation