TC45DA Hydraulics Quit Working

[jvacura]

Thought I would hit you guys up for some info.
The hydraulics on my father in laws TC45DA up and quit on him today. He said he had just got on the tractor and started it. He lifted the bucket up and started to tip the bucket and it quit moving. No response on the joystick. Three point also quit working. Fluid levels were all good and no abnormal noises or sounds. Up to that point it had given him zero problems. Any ideas were to start looking for problems? Any known issues? Thought I would check before we tore into into blindfolded....
Thanks,
Jon

 

[jinman]

Look at the engine's dipstick to check for high/overfull fluid. There's a good chance he blew the seal on the hydraulic pump and all fluid is going into the engine's crankcase. In that case, the oil rises quickly inside the engine and may overflow. If that is not the case, does the HST transmission still work okay? If the HST is stalling too, then check the big hydraulic filter between the right-rear tire and the running gear. That filter might be loose and letting air into the system. After checking there, look at the rubber "T" in the large hydraulic line just under the right side operator platform. Sometimes the clamps get loose and those can leak air. Finally, check the hydraulic connections on the hydraulic pump to make sure they are tight.

DO NOT run the tractor long with this problem. If the pump goes dry, it will do permanent damage.

 

[J_J]

If you have any QD's on the loader, check and reset them.

Check the hyd pressure using a gage in one of the QD's, or install a gage in the IN port of the FEL valve.

Is the pump even turning?

 

[jvacura]

Look at the engine's dipstick to check for high/overfull fluid. There's a good chance he blew the seal on the hydraulic pump and all fluid is going into the engine's crankcase. In that case, the oil rises quickly inside the engine and may overflow. If that is not the case, does the HST transmission still work okay? If the HST is stalling too, then check the big hydraulic filter between the right-rear tire and the running gear. That filter might be loose and letting air into the system. After checking there, look at the rubber "T" in the large hydraulic line just under the right side operator platform. Sometimes the clamps get loose and those can leak air. Finally, check the hydraulic connections on the hydraulic pump to make sure they are tight.

DO NOT run the tractor long with this problem. If the pump goes dry, it will do permanent damage.

I'll have him check the crankcase for excess oil. The oil level was good on the hydraulic stick, so I'm not sure that's the problem. He didn't run it long after it quit working. I did check quickly under the tractor for loose lines or fittings and didn't notice anything. The "T" looked good but we can double check. Hydrostatic transmission is working fine as is the power steering.

 

[jvacura]

If you have any QD's on the loader, check and reset them.

Check the hyd pressure using a gage in one of the QD's, or install a gage in the IN port of the FEL valve.

Is the pump even turning?

I did check the QD's and they were all good.
I actually don't think the pump is turning. There doesn't seem to be any pressure at any of the lines, but I couldn't be sure till I put a gauge on it.

 

[jinman]

You could have sheared off the pump's driveshaft, but I think that kind of failure is very uncommon. This would be the first one I've heard of. There are lots of pumps out there that have blown seals including my own. When you consider there's 10 gallons of fluid in the reservoir, you could pump half a gallon into the engine and hardly notice the loss in the reservoir.

There's one other thing it could be. The hydraulic relief valve is located in a diverter block under the right side operator's platform. If the relief valve lifted and stuck open, it could cause the problem. Tomorrow morning I will download an illustration so you can see where the relief valve is located and check it. Normally when the relief valve opens you can hear it, but if your dad is like me and doesn't hear so well, he may not hear the hissing/squealing of the valve.

EDIT: By the way, do you know where the main hydraulic pump is? Its on the right side of the engine just in front of and below the injector pump. The large pump is the main pump and in front of it near the fan and belt is a smaller power steering pump. What year model tractor is your dad's? On some of the later models, they removed the power steering reservoir and added piping so the steering pump draws fluid from the main reservoir. If there is a big black reservoir about 1 liter in size on the right side near the top of the engine, then you have the PS reservoir. Otherwise if it is not there, the PS system draws from the main reservoir.

 

[J_J]

Use a hyd pressure gage to check pressure.

You could remove the lift cyl hose and run the hose into a bucket to see if the pump is pumping. If you get about 2 gal in 15 sec = 8 GPM flow rate.

You could also loosen a fitting at the pump or FEL valve and see if any fluid flow out. Put a rag over the fitting.

 

[jinman]

Here are some illustrations and a photo that may help you. The first is the diverter valve under the right side operator platform. The red arrows point to the location of the system relief valve on the bottom of this block. You will have. Where 7,8, and 10 are shown on the top illustration, you have piping because this is where the loader attaches to the hydraulics.

The photo shows the main and PS hydraulic pumps (the big pump on the left is the main pump). I would not recommend trying to open the lines at the main pump as J_J suggested because they are flange fittings and you cannot attach a gage there. Do all your pressure testing at the diverter block or other piping with normal pipe connections.

If you have to remove the hydraulic pump, the pressure line on the bottom and the mounting bolts are a challenge. You'll need a 3/8" shallow socket set (metric of course) and a universal joint adapter because the 4 bolts holding the bottom flange on the pump are a bear to get to. You'll need a box end/open end wrench to get to the back side pump mounting bolts because it's a tight spot with the fan and belt interfering. Also, there is an oil line (pipe) behind the main pump that attaches to the engine block with a banjo fitting. The bolt has to be removed from the banjo fitting to allow the main pump to be pulled out of the drive flange on the engine.

 

[RobertN]

I had this happen on a previous tractor. A stick poked/rubbed over one of the loader hydraulic quick connects. Presto, no hydraulics. And, visually, you could not tell. Finally disconnected and reconnected them; worked fine. Scared me at first; I just saw $$$$$ for repairs in my mind. I called the tractor shop I use; he said to check the QC's. I did a visual; they "looked" fine. I actually got it loaded on the trailer, dragging implements, and got it over to his shop. He asked if I checked the QC's. I said ya... He didn't even look at them... He just reached in, disconnected and reconnected them. Everything worked; life was good. Then he said, "I thought you said you checked them.". Now I do visual checks, AND reseat or test stuff like that.

It deadheaded my pump. I lost HST too. But that was an older Kubota B series. I think the pump system on the TC40/45 series may be different?

If you have any QD's on the loader, check and reset them.

 

[jinman]

The reason this does not sound like QDs to me is that he said none of the loader worked and neither does the 3PH. If one QD was loose, it would effect only the curl or lift associated, not both. Centering the joystick would allow the 3PH to operate. If the loader valve's power beyond plug was loose, the loader would still work, but the 3PH would not. The only three things that can cause the symptoms as described are:

1. blown pump
2. stuck system relief
3. pump drawing air

The fact that the HST works normally is a good indication that #3 is not the problem since they use the same piping, so I'm putting my money on #1 or #2.