Another thought: Is the hydraulic pump not doing it's job?

But why is there an oil leak then at the motor?

 

If the mid lift works, especially if you can make the limit squeal, then the pump is doing something.

If the tractor won't move in cold weather, when is the last time you drained the oil out of hte rear end and replaced it? We have seen ice frozen in the bottom of the rear end that prevented the tractor from moving.

Is the oil leak from the motor or the lines? Depending on tractor and use we have seen the lines at the motor get loose and leak.

Rebuilding hte motor is pretty tough. Generally people just replace them. Just make sure you get a motor off an 4xx tractor and NOT a motor off of an 2xx tractor.

 

Thanks, I'll check if the lift piston is moving or not.
The leak I saw was coming from the outer End Cap, part no. 14837. It seems to have an o-ring behind.

I'll check the leak point again, now that the driveway is cleared from snow.

I checked my parts manual and there seems to be a seal Kit , part no. C 19037x

Martin

 

My 224-78 would not move once :shock: I think my pant leg cuff caught the shift lever, as the joint at the bottom of the lever had popped apart. Easy fix if that happened.

:cheers:
Gordy

 

I'll check my records when the gear oil was changed last (I hope that is what you were asking). It was about 1.5 years ago when I rebuilt the rear axle.
If I heat up the tractor then this problem would go away.

Best, Martin

 

Check your IM Martin.

Bill Moyer

 

I've seen a cap blow off a pump and a cylinder, but never a motor. I don't think freezing water could break them either, but there's always a first. Maybe the bolts were just a little loose and pumping the cold oil caused enough pressure to leak. If the transaxle is frozen, the engine must be laboring. I suggest warming the tractor up, and trying again.
You can replace just the rear seal, but I would take motor off and stand up on shaft end (in vise); the bolts hold a stack of parts together that you don't want to disturb.

Was oil foamy?

 

i have used hydraulic motors if you need 810-348-6311

 

Hi Hydrogeek,

I have no clue what can go wrong with a hydraulic motor but probably it is possible.
I checked the leak point again at the motor and the oil puddle on the garage floor. The oil clearly came out from the outer cap... this area is also wet.

I was testing the lift piston and it still works... this means that the pump is working.

To those who know these motors well enough: What can internally go wrong to make the tractor do what mine did: It quit running forward and backward.

Best, Martin

 

Martin

When you say it's leaking oil, you must determine if the oil is coming from the hydraulic system and where.
Yes your pump can be bad and the lift circuit may still work, it takes less pressure and flow than the drive motor.
If memory serves me your 444 is repowered with a Vanguard engine?

Thanks
Jim

 

Hi Jim
yes this is correct my tractor has the Vanguard engine. Actually the original tractor was a 446- my mistake- and I had it completely renovated 2 years ago. I was running very nicely, like never before and now it quit.
The oil leak from the hydraulic motor is from the cap plate and the outer left end facing the left wheel. Leak is not from the two oil lines.
Although not much oil pushed out of there. It pushed out when I had the engine running and put the lever into forward.
I also shifted into reverse and then there was a response from the engine telling me that the pump was building up pressure and then it started leaking again.

As an engineer I wonder what damage might have happened inside the motor to have it give up entirely all of a sudden?
Also if the pump is the problem and the pressure output were lower than spec... then at least the hydo motor should be pushing at least a little forward or reverse?

Is there anybody out there who had the same issues?

Best, Martin

 

my $.02, if its the motor, replace it:https://www.ebay.com/itm/Case-Inger...ydraulic-drive-motor-C33234/174615310733?hash=item28a7e2318d:g:2BYAAOSwvWtgEyO2

 

Are all the heads on the bolts? If the cap has moved out far enough, the timing disc could have disconnected from the end of the dog, but it would have not gone back into place, ie. cap would still be cocked.

Oh, just had a thought; the stack I was talking about is in a tube, maybe one of the pieces is cracked and the oil is coming out tube just under cap.

You need to take off and take pictures.

 

heads on bolts? No idea (what you mean).
I think nothing is lost, all head bolts are there. There is only an oil leak.

But I have not started to dig up that motor for closer inspection.

How high are chances that the pump and control valve underneath are involved in the problem?

Martin

 

Here is a quick update on my hydraulic motor project: Bill sent me a spare hydraulic motor and I'll swap the motors soon.

I can just hope that the new motor will solve the case.
Question for the pros: What is the best way to drain the hydraulic oil out if the system?
I remember I am good at creating a mess here 😀.
The best thing would be a small valve for drainage.... but it does not grow by itself.
Best, Martin

 

A small 1/4" NPT plug on the bottom of the travel control valve under your left foot. Allen key.

 

 

Please help

I cleaned the old hydraulic motor a bit and saw the o-ring in the groove sealing against the gear box: cooked.
Does someone know what size o-ring that is. Could be a 3" x 1/8" but not sure.
As I am there does it make sense to change other seals inside as well? What o-ring sizes are used and where are they hiding?

Martin

 

Thanks iko and sdunt for pointing out the drain and test port!
great.... I'll drain the oil and after the motor swap I will hook up a hydraulic test port (Stauff with a check valve) ...so I can measure the health of the pump.
What pressure are expected?
I need to build an adapter for the 1/4NPT port. Like a male 1/4NPT to female M10 x 1 (Stauff test port has a M10 x 1 tread)
Martin

 

Seals at hydraulic motor

I see the exterior seal is #34

Does anyone know the size of that ring 30095?

Then inside there are only 2 seal rings (#6) for the 'tube'. Who knows the 2 o-rings (size)?
And one seal ring #14 inside.
There was a seal kit #19037. Does this kit still exist?

I think it is relatively simple to open the cap (7 bolts?)
Is it worth opening that motor?

Or do you recommend to just install the motor and done with it?
Martin

 

Seals at hydraulic motor

I see the exterior seal is #34

Is this #34 seal one of these?
The diameter measured with the caliper inside the groove is 3.026"
OD of flange is 3.25"

So I guess the 234 o-ring would fit, but I am not very familiar with the imperial o-rings, nominal size and actual size are different. I looked up a chart and it seems to fit

If someone knows the other o-rings size (inside the motor) please share.

Martin

 

Your pressure gauge better go up to 3000 psi. The highest pressure you'll see will probably be between 1000 and 2000 psi, and Max will be when you go forward or backwards against an immovable object like a tree. Be careful whatever you do, hydraulics can be really dangerous.

 

Thanks iko for your warnings, appreciated.
I am very familiar with hydraulics (engineer) and I am working a lot with old Mercedes 600 hydraulics and W126 hydraulic suspension (I repair them). They all run on 200bar (3000psi) pressures. So I am well equipped to tackle this problem.
When I have the gauge hooked up I'll check the pressure when driving against the tree lol...
I am just curios how to test the hydraulic pump output?
Martin

 

Output? Flow or pressure?

Keep in mind that the tcv has a pressure relief valve. When going against the tree it will probably squeal.

Here are some possible scenarios.

• you go against the tree and both wheels lock. Record the pressure on the gauge. Why are the wheels not moving? Either the relief valve is not set right, or oil gets pass the motor or pump.
• if one wheel locks and one turns you can't really draw any conclusion related to the max pressure the pump can generate.

You probably don't care about the flow rate now.

 

hi Iko, all I care about is a judgment about the pump. Is there a common test procedure: How to you determine a good pump vs a bad pump?

 

Martin,
In the service manuals section of the technical library under the hydraulic section is a number of manuals for trouble shooting and testing the hydraulic system. Don't know if you have been there yet, but if you find the test manual for your tractor, it shows what to do to test it. And what you're readings should be.
🤓 Tim

 

Yes, the O Ring of the motor to axle case is a -234.

C28949 } O RING

O RING

salempwr.com

An item we keep in stock of course.

Brian

 

Yes, the O Ring of the motor to axle case is a -234.

C28949 } O RING

O RING

salempwr.com

An item we keep in stock of course.

Brian

What Brian said [emoji846]

 

Thanks Brian and all.
I was looking at the hydraulic section of the library.

I found some good information
Here is one for the analysis of what happened. I have no proof yet that the problem was the motor.... yes there was an external leak but not much oil came out. If the motor is the problem it must be internal damage.
The cause for the tractor not moving can be the pump, TCV or the motor.

Well at least there was a response from the motor with the external leakage. This should tell a story at least.
If it were the control valve (internal leakage /relief valve damaged or open) then there would have been no response from the motor because no pressure would have reached the motor.
The same was true if the pump had a damage.... why would the motor leak all of a sudden?
Even though I don't know for sure simple logic tells me that chances are the problem is the motor and less chances the problem is the TCV or pump.

This means for me right now that I'll go and install the 'new' motor and the check if the tractor is back or not.
I am happy about any comments from you about this approach.

Best, Martin

 

I was trying to remove the old hydraulic motor.... very tight spaces. I can't break the upper 2 bolts lose with a 12 point 1/2" tool. It seems I need to remove the rear axle from the frame to gain better access?
That is probably what I need to do because I don't have any magic tool that would fit. The bottom two bolts I could remove by cutting the socket short in order to get a ratchet +socket in place but that does not work on the upper 2 bolts. Probably these bolts were never moved since 1976.
Martin