GC2600 whining gone, then came back

   / GC2600 whining gone, then came back
  • Thread Starter
#21  
Hooked tiller up. Raising it with lift and driving with the load caused to oil foam. Was clear. Engaging the PTO for 15 seconds, then disengaging caused total foam in eyeglass.

Going to change out the fluid and get a new hydraulic filter.
 
   / GC2600 whining gone, then came back #22  
should suck DOWN with eng running. least my 2400 does, manual says too check level fel down, bucket curled down UP (edited to correct), 3pt lowered. with fel off and 3pt up low on glass (eng off) lower 3pt level is where it should be.
your eng running and level is right then eng off level low confuses me.
 
Last edited:
   / GC2600 whining gone, then came back
  • Thread Starter
#23  
Is the foam from the PTO gears turning in the oil? If pump was cavitating it would be happening all the time and not just when PTO is engaged.

I know that running the PTO on both the BX1850 I used to have and 2400H I currently have heats the oil up more than just driving around without PTO engaged.
It only foams when the PTOs are engaged. I'm not for sure how the PTO gears work inside the transmission. Are the PTO gears under pressure?

But the steel line #11 that connects to the PTO engage lever constantly whines. Almost screams. Whether engaged or not. The line isn't kinked.

Could it be blocked? Could it be related? Could it be the pressure relief valve? Or PTO valve?
Screenshot_20250605_234619_Gallery.jpg


FEL, steering, and 3pt lift cause no foam.
 
   / GC2600 whining gone, then came back #24  
Have not replied to this thread but I will say, one, its a sightglass, not an eyeglass and two, most all hydrostats whine to a certain extent, it's an inhereht characteristic of the transmission.

Far as the 'bubbles' or foam appearing in the sightglass, sounds to me like you have a compromised suction side hose or a failed suction side pipe going to the pump. Filters have nothing to do with causing foam unless they have a compromised sealing gasket. If it's a flexible hose feeding the pump, remove it and pressurize it with compressed air to say 30 PSI and observe it for air leaks and if it's a hardline, remove it and carefully inspect it for cracks or holes and if you find nothing, reinstall it with NEW sealing washers and make sure the fitting nuts are tight. Kubota's were notorious for cracks in the input hoes to the pump and they even issued a recall - fix for it.Most all quaility hudraulic oil will hava an anti-foaming additive in it to begin with. Cheapo hydraulic oil (fluid) like Tractor Supply Traveler fluid won't. Like everyting in life today, you get what you pay for.
 
   / GC2600 whining gone, then came back
  • Thread Starter
#25  
should suck DOWN with eng running. least my 2400 does, manual says too check level fel down, bucket curled down, 3pt lowered. with fel off and 3pt up low on glas (eng off) lower 3pt level is where it should be.
your eng running and level is right then eng off level low confuses me.
With FEL down bucket curled, 3 pt lowered, engine running, glass is middle.

Turn engine off, oil drops to below glass.

I released any pressure on FEL and 3pt, always do when getting off.
Then topped off the oil to middle. Took about 20-25 oz or so.
Start it up and then oil went above 3/4th.

Weird.
I repeated the same process. Oil at over 3/4 while running. Turn off engine. Goes down to slightly under half. 🤷

Where does the oil get pull into? Usually, I turn off engine and releave pressure in bucket and 3pt the oil in eyeglass goes up.

How much fluid does the hydraulic filter hold? This foaming didn't start until I changed that filter.🤷

I'm at a loss.
 
   / GC2600 whining gone, then came back #26  
It only foams when the PTOs are engaged. I'm not for sure how the PTO gears work inside the transmission. Are the PTO gears under pressure?
Gears are not under pressure but turning at high speed in the oil which could cause foaming or some aeration from splash. If you run PTO with engine at idle does oil foam?

Is foaming different when running rear PTO vs mid PTO? Different gears at different speeds so may have different results.
But the steel line #11 that connects to the PTO engage lever constantly whines. Almost screams. Whether engaged or not. The line isn't kinked.

Could be the PTO relief that is unstable causing vibrations in steel line. That could change with engine RPM, fluid temperature, etc.
Could it be blocked? Could it be related? Could it be the pressure relief valve? Or PTO valve?View attachment 3613818

FEL, steering, and 3pt lift cause no foam.
Try driving at full speed for a period of time with PTO off to see if oil shows any signs of foam. Reason for this test is to see if gears from transaxle may also aerate oil at full travel speed operation.

I doubt hydraulic problem since only happens with PTO spinning.

How long does tractor have to sit before oil is clear?
 
   / GC2600 whining gone, then came back #27  
does the 2600 come with backhoe? think not,think was 2610 had it, but want to check.
 
   / GC2600 whining gone, then came back #28  
Now I'm curious about the line to the PTO valve and your description of the noise it makes. That can't be right. Does that line get warm to the touch quickly? That would certainly make me wonder what's going on in there.
 
   / GC2600 whining gone, then came back #29  
Now I'm curious about the line to the PTO valve and your description of the noise it makes. That can't be right. Does that line get warm to the touch quickly? That would certainly make me wonder what's going on in there.
I am curious If the PTO relief is unstable would that steel line resonate? That would kind of explain working then quit but don’t explain why it became unstable. Also not sure if the PTO relief is constantly unloading a little flow or more of a pressure reducing valve maintaining a preset pressure to PTO circuit. Either way could be unstable..
 
   / GC2600 whining gone, then came back #30  
I'm not at all familiar with that tractor, but many similar systems pipe return oil from the steering circuit through a pressure reducing or regulator valve maintaining 200 to 300 PSI. That flow is then used to supply hydrostat charge pressure, PTO, any other clutch packs or low pressure functions. I'm really wondering what's going on in that circuit?
 
   / GC2600 whining gone, then came back
  • Thread Starter
#31  
Gears are not under pressure but turning at high speed in the oil which could cause foaming or some aeration from splash. If you run PTO with engine at idle does oil foam?

Is foaming different when running rear PTO vs mid PTO? Different gears at different speeds so may have different results.


Could be the PTO relief that is unstable causing vibrations in steel line. That could change with engine RPM, fluid temperature, etc.

Try driving at full speed for a period of time with PTO off to see if oil shows any signs of foam. Reason for this test is to see if gears from transaxle may also aerate oil at full travel speed operation.

I doubt hydraulic problem since only happens with PTO spinning.

How long does tractor have to sit before oil is clear?


Thanks for clarifying how the gears work and for the questions and suggestions.

Ran the tractor for about 2-3hours.
Borrowed a friend's zero turn, almost 2 weeks with tractor down, grass was tall. 1 ¹/2 acres. Mowed into rows raked into piles. Put forks on tractor and ratchet strapped a tarp onto forks. Daughter drove, I filled the tarp and bucket.

She drove back and forth dumping grass running full speed in fast gear. Checking sightglass often. Used the FEL. Not a single bubble. Always clear fluid. Checked temp couple of times and afterwards. Top temp at hydro filter was 135⁰F. Steel PTO line top temp was 125⁰F.

After grass, I watched the oil while she ran the mid-PTO with engine at 1500 rpm for 30 seconds. Fluid was all foam after 10 seconds. Looked the same as if at 3000 rpm. Takes about 2-3 minutes for oil to clear.

I put on the tiller Saturday. Ran it 15 seconds and oil was foam.

Steel line to PTO valve has never been hot to the touch. Really nothing on the transmission or hydraulics has ever been too hot to touch.

Not sure where the PTO relief is.

A shot in the dark. I see on the parts diagram:
#9 4264757M1 SCREW PLUG
#10 3758117M1 SCREW PLUG SEAL
Both where the steel line and the PTO valve connect to the hydraulic lift cover.

What are they? Are they under pressure?
 

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   / GC2600 whining gone, then came back
  • Thread Starter
#32  
does the 2600 come with backhoe? think not,think was 2610 had it, but want to check.
Your correct. No backhoe on the 2600
 
   / GC2600 whining gone, then came back #33  
Thanks for clarifying how the gears work and for the questions and suggestions.

Ran the tractor for about 2-3hours.
Borrowed a friend's zero turn, almost 2 weeks with tractor down, grass was tall. 1 ¹/2 acres. Mowed into rows raked into piles. Put forks on tractor and ratchet strapped a tarp onto forks. Daughter drove, I filled the tarp and bucket.

She drove back and forth dumping grass running full speed in fast gear. Checking sightglass often. Used the FEL. Not a single bubble. Always clear fluid. Checked temp couple of times and afterwards. Top temp at hydro filter was 135⁰F. Steel PTO line top temp was 125⁰F.

After grass, I watched the oil while she ran the mid-PTO with engine at 1500 rpm for 30 seconds. Fluid was all foam after 10 seconds. Looked the same as if at 3000 rpm. Takes about 2-3 minutes for oil to clear.

I put on the tiller Saturday. Ran it 15 seconds and oil was foam.

Steel line to PTO valve has never been hot to the touch. Really nothing on the transmission or hydraulics has ever been too hot to touch.

Not sure where the PTO relief is.

A shot in the dark. I see on the parts diagram:
#9 4264757M1 SCREW PLUG
#10 3758117M1 SCREW PLUG SEAL
Both where the steel line and the PTO valve connect to the hydraulic lift cover.

What are they? Are they under pressure?
I do not see what looks like the PTO relief or charge relief in either of those screen shots. I suspect that the PTO relief maybe part of the PTO valve assembly but am not certain of that.

Does the sound change when tractor engine is at idle? Does it change when oil is cold vs warm or at operating temperature?

125 - 135 degrees F sounds like a normal operating temperature and is nothing I would be concerned about.

Great job on running the tests and gathering all the information.
 
   / GC2600 whining gone, then came back #34  
<snip>

Not sure where the PTO relief is.

A shot in the dark. I see on the parts diagram:
#9 4264757M1 SCREW PLUG
#10 3758117M1 SCREW PLUG SEAL
Both where the steel line and the PTO valve connect to the hydraulic lift cover.

What are they? Are they under pressure?
The PTO relief valve is items #6-8 on the diagram.

Items #9-10 are fittings/seal. They are always under pressure but that should be limited to about 79psi by the PTO relief valve, which allows the fluid to return to the sump via the hydraulic oil filter.

This is fed from the return from the steering valve.
 
   / GC2600 whining gone, then came back #35  
Dinico
I just went back and read this whole post again and it brought up some questions or thoughts.

I saw one of posts where you attached a screenshot of the PTO engagement valve and the line that resonates or is noisy. Looking at that valve is it lever operated rotary valve that engages the PTO? If yes is it possible that lever - valve assembly is not rotating fully? Reason for wondering is if it possibly rotate to a position where it bleeding off a little pilot flow which might aerate the oil when PTO is engaged.

I seriously doubt the foaming - aeration has anything to do with the suction line or filter since that is always in the loop when tractor is running.

If I understand correctly the foamy happens with either rear PTO or mid PTO so back to only common things arePTO gears spinning but would suspect different gears for rear vs mid and pressure going to PTO clutch so everything from engagement valve to clutch is suspect which leads back to original question on type of PTO engagement.
 
   / GC2600 whining gone, then came back #36  
Your correct. No backhoe on the 2600
I asked due to incorrect return line hookup can cause odd sight glass issues.
same if you had power beyond addon (rear hydro lines) and return hooked wrong.
 
   / GC2600 whining gone, then came back
  • Thread Starter
#37  
The PTO relief valve is items #6-8 on the diagram.

Items #9-10 are fittings/seal. They are always under pressure but that should be limited to about 79psi by the PTO relief valve, which allows the fluid to return to the sump via the hydraulic oil filter.

This is fed from the return from the steering valve.
I asked due to incorrect return line hookup can cause odd sight glass issues.
same if you had power beyond addon (rear hydro lines) and return hooked wrong.
Dinico
I just went back and read this whole post again and it brought up some questions or thoughts.

I saw one of posts where you attached a screenshot of the PTO engagement valve and the line that resonates or is noisy. Looking at that valve is it lever operated rotary valve that engages the PTO? If yes is it possible that lever - valve assembly is not rotating fully? Reason for wondering is if it possibly rotate to a position where it bleeding off a little pilot flow which might aerate the oil when PTO is engaged.

I seriously doubt the foaming - aeration has anything to do with the suction line or filter since that is always in the loop when tractor is running.

If I understand correctly the foamy happens with either rear PTO or mid PTO so back to only common things arePTO gears spinning but would suspect different gears for rear vs mid and pressure going to PTO clutch so everything from engagement valve to clutch is suspect which leads back to original question on type of PTO engagement.
Odd question. If I take the oil filter off first with the fill cap off, shouldn't more than a quart of fluid drain?
 
   / GC2600 whining gone, then came back
  • Thread Starter
#38  
Dinico
I just went back and read this whole post again and it brought up some questions or thoughts.

I saw one of posts where you attached a screenshot of the PTO engagement valve and the line that resonates or is noisy. Looking at that valve is it lever operated rotary valve that engages the PTO? If yes is it possible that lever - valve assembly is not rotating fully? Reason for wondering is if it possibly rotate to a position where it bleeding off a little pilot flow which might aerate the oil when PTO is engaged.

I seriously doubt the foaming - aeration has anything to do with the suction line or filter since that is always in the loop when tractor is running.

If I understand correctly the foamy happens with either rear PTO or mid PTO so back to only common things arePTO gears spinning but would suspect different gears for rear vs mid and pressure going to PTO clutch so everything from engagement valve to clutch is suspect which leads back to original question on type of PTO engagement.
The PTO engagement valve is lever operated. Seems to be a rotary valve. I'm looking at it now. I fully engaged the lever, then disconnected the arm that connects to it.

So when lever is fully engaged, the valve is open as far as it can. And when disengaged, the valve is closed as far as it can be.

I have looked for an actual picture of the valve, but couldn't find one.
 
   / GC2600 whining gone, then came back #39  
video it happening, including the frothing and level changes, upload to youtube and post link here so we can see/hear it.
 
   / GC2600 whining gone, then came back
  • Thread Starter
#40  
video it happening, including the frothing and level changes, upload to youtube and post link here so we can see/hear it.
Excellent idea, will do that.

I had decided to change out the fluid. Removed cap, and removed hydraulic filter first. Should more than a quart drain out?
 

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