MF165 massive hydraulic fluid "weep hole" leak

[dcharette]

Hello all!

I'm the proud owner of a 1965 MF165 with an AD4.203 diesel and multi-power transmission which was restored by the previous owner to a near original state about 5 years ago. The only thing they didn't rebuild was the drive train and transmission.

Today I was out plowing and after about an hour of use, I noticed reduced hydraulic pressure and could no longer lift the plow. I got down to find the main "weep hole" under the transmission leaking with a steady stream and the 2nd "weep hole" just under the end of the engine where it bolts to the transmission leaking in droplets about once a second.

I've verified at least that the fluid is NOT engine oil, but appears to be hydraulic/transmission oil. The engine oil dipstick still reads full and the leaking oil is a different color than the engine oil, so that's at least my "verification."

My question is simply what should I be looking for as the cause? I'm guessing that the oil seals on the input shaft to the transmission might be the culprit as they're most likely the originals and potentially 50 years old. Is there anything else in this multi-power transmission that could be leaking?

I was using the multi-power function in low when plowing deep today before the failure and when I had the plow raised switched to high and was making the turns around to re-enter the field and then switching back to low. So, is there anything with that clutch/linkage/valve for the multi-power that could be suspect to this leak?

And finally, the previous owner never utilized the hydraulics, and so is there anything with the hydraulic pump or associated components that could be suspect to cause the leak to pass back to the transmission housing and out the "weep holes?"

Thanks a million for any insight or help you could give me. I just don't want to go to the work of splitting open the tractor without having some sense of confidence of where I'm targeting to make the repair.

Have a nice day!

Dan

 

[DJ54]

There is a hyd. line that comes off the Aux. hyd. pump that activates the Multi-Power. It is half metal tube/half rubber hose. It could be the rubber hose part has a leak. Bad thing is, you need to remove the top of the transmission to get to it.

Then again, it may be the seals, as you mentioned.

Doubt you'll find out exactly what it is, without some disassembly.

I had a 180, that the Multi-Power had gone out on. I found out after I bought it, that they can be very expensive to fix, if not fixed when problems first arise. I had no problems with it, as long as I ran it in the low side. I ended up selling it, and never fixed the Multi-Power, so never got into anything, except repairing the hydraulic pumps..

 

[SIMassey]

Hello all!

I'm the proud owner of a 1965 MF165 with an AD4.203 diesel and multi-power transmission which was restored by the previous owner to a near original state about 5 years ago. The only thing they didn't rebuild was the drive train and transmission.

Today I was out plowing and after about an hour of use, I noticed reduced hydraulic pressure and could no longer lift the plow. I got down to find the main "weep hole" under the transmission leaking with a steady stream and the 2nd "weep hole" just under the end of the engine where it bolts to the transmission leaking in droplets about once a second.

I've verified at least that the fluid is NOT engine oil, but appears to be hydraulic/transmission oil. The engine oil dipstick still reads full and the leaking oil is a different color than the engine oil, so that's at least my "verification."

My question is simply what should I be looking for as the cause? I'm guessing that the oil seals on the input shaft to the transmission might be the culprit as they're most likely the originals and potentially 50 years old. Is there anything else in this multi-power transmission that could be leaking?

I was using the multi-power function in low when plowing deep today before the failure and when I had the plow raised switched to high and was making the turns around to re-enter the field and then switching back to low. So, is there anything with that clutch/linkage/valve for the multi-power that could be suspect to this leak?

And finally, the previous owner never utilized the hydraulics, and so is there anything with the hydraulic pump or associated components that could be suspect to cause the leak to pass back to the transmission housing and out the "weep holes?"

Thanks a million for any insight or help you could give me. I just don't want to go to the work of splitting open the tractor without having some sense of confidence of where I'm targeting to make the repair.

Have a nice day!

Dan

There are seal rings on the input shaft to the transmission that direct hydraulic fluid to the multipower clutch. These rings wear grooves in the area that they seal and start leaking. Try running the multi power in low for an extended time and see if the leak stops. There is no pressure to the multipower clutch in low. Remember it will free wheel with no engine breaking.

If it still leaks, its likely the input shaft seal or the multipower valve in the bell hoiusing.

 

[flusher]

There is a hyd. line that comes off the Aux. hyd. pump that activates the Multi-Power. It is half metal tube/half rubber hose. It could be the rubber hose part has a leak. Bad thing is, you need to remove the top of the transmission to get to it.

Then again, it may be the seals, as you mentioned.

Doubt you'll find out exactly what it is, without some disassembly.

I had a 180, that the Multi-Power had gone out on. I found out after I bought it, that they can be very expensive to fix, if not fixed when problems first arise. I had no problems with it, as long as I ran it in the low side. I ended up selling it, and never fixed the Multi-Power, so never got into anything, except repairing the hydraulic pumps..

Had the same problem with the MP on my 1964 MF135 diesel. Same solution: kept it in MP Low range and ran it like that for about 8 years until I sold it.

 

[banjodunn]

G'day I had a customer with a 178 like that once and found a bolt had come out of the M/P control valve that the valve lever works on, it is visible from the inspection plate under the tractor HOWEVER I could not get it in and tight without splitting the tractor (easy job on those old girls ). I would remove the inspection cover and have a look and see if you can see where it is coming from

Jon

 

[dcharette]

Hi All,

Thanks for all the great feedback. I feel a little more comfortable about the issue now.

I've attached an image of the location of the "weep hole" leaks. I've also got a parts breakdown pic of the transmission. And based on the comments at this point is that when I was using the multi-power in "HI", there was plenty of hydraulic pressure that seeped out around the input shaft and seals due to those sealing rings possibly grinding into the shafts and of course the oil seals being as old as they are. I will hopefully have some time today to refill the transmission with oil and try running the tractor multi-power in "LOW" and see if I get a leak again. If not, I can switch to "HI" and monitor it closely and see if the leaking starts. I suppose if it does, then I know where the leak is.

Does this seem like a reasonable guess/test without harming anything as long as I don't go too long before I see a leak again? Is it possible if the leak is high enough around the input shaft that it could actually spray onto the clutch and cause damage?

Thanks guys!

 

[TomSeller]

That sure looks like a nice restoration job !

 

[SIMassey]

Hi All,

Thanks for all the great feedback. I feel a little more comfortable about the issue now.

I've attached an image of the location of the "weep hole" leaks. I've also got a parts breakdown pic of the transmission. And based on the comments at this point is that when I was using the multi-power in "HI", there was plenty of hydraulic pressure that seeped out around the input shaft and seals due to those sealing rings possibly grinding into the shafts and of course the oil seals being as old as they are. I will hopefully have some time today to refill the transmission with oil and try running the tractor multi-power in "LOW" and see if I get a leak again. If not, I can switch to "HI" and monitor it closely and see if the leaking starts. I suppose if it does, then I know where the leak is.

Does this seem like a reasonable guess/test without harming anything as long as I don't go too long before I see a leak again? Is it possible if the leak is high enough around the input shaft that it could actually spray onto the clutch and cause damage?

Thanks guys!

The one thing that puzzles me is that you say the multipower works in high. Does it seem to engage securely or does it kinda slip in? The multi power hydraulic pressure is fairly low. If the seal rings are leaking, it would reduce the pressure available to shift and hold the clutch in high multipower. If the multipower is not shifting into high securely, the clutch will be slipping and damage the clutch. High cost and major teardown to repair.

On my 135 , I replaced the seal rings because there was leakage into the clutch area. I don't have the leakage anymore but the multipower still doesn't work. I did get it to work one day, shifted really solid, but hasn't lately. I'm not sure whether the pump pressure is low or the rings are leaking fluid internally back into the transmission. I run the multi power in low now, to prevent the clutch from partially engaging and damaging it before I can repair the cause.

If the seal rings are leaking, the oil will run into the clutch disks.

 

[dcharette]

Thanks guys for all the comments!

SIMassey, when I was using the multipower in HI the other day before seeing the leaking, it was shifting smoothly and locking in just fine.

I ran the tractor today for about an hour. I rigged up a bucket underneath the "weep hole" to catch the drippings as I drove around and tested it. And while running it in low, the leak is definitely diminished, but not stopped. Now, once warmed up, I ended up with a drop per second or so.

As well, I've also noticed that there is a sputtering of oil coming out of a window in the bell housing where you can see the flywheel. So, that pretty much pinpoints the leak to the input drive shaft as it must be seeping through even without the high pressure applied in HI mode on the multipower pushing the oil.

So, it's pretty clear I'll need to split the tractor to get at those seals. But, also, what about the drive shaft that the seal rings go around, could the shaft be worn down now in the position where the rings are? And, if so... is it possible to weld and fill material back in the grooves and machine it back true or would I need to just get all new shafts?

And finally, I have a little bit of plowing yet to do this week before putting the tractor to bed for the winter. If I continue to run it, will I do any damage to the clutch/flywheel area in the bell housing if I watch and maintain my oil levels and just catch these drippings? SIMassey, as you said with your 135 oil leaking onto the clutch discs, were you talking about the clutch discs for the multipower or the main clutch? And is it possible in my condition now as I've described it for oil to get onto the main clutch and cause damage to it?

Thanks all!

Dan

 

[SIMassey]

Thanks guys for all the comments!

SIMassey, when I was using the multipower in HI the other day before seeing the leaking, it was shifting smoothly and locking in just fine.

I ran the tractor today for about an hour. I rigged up a bucket underneath the "weep hole" to catch the drippings as I drove around and tested it. And while running it in low, the leak is definitely diminished, but not stopped. Now, once warmed up, I ended up with a drop per second or so.

As well, I've also noticed that there is a sputtering of oil coming out of a window in the bell housing where you can see the flywheel. So, that pretty much pinpoints the leak to the input drive shaft as it must be seeping through even without the high pressure applied in HI mode on the multipower pushing the oil.

So, it's pretty clear I'll need to split the tractor to get at those seals. But, also, what about the drive shaft that the seal rings go around, could the shaft be worn down now in the position where the rings are? And, if so... is it possible to weld and fill material back in the grooves and machine it back true or would I need to just get all new shafts?

And finally, I have a little bit of plowing yet to do this week before putting the tractor to bed for the winter. If I continue to run it, will I do any damage to the clutch/flywheel area in the bell housing if I watch and maintain my oil levels and just catch these drippings? SIMassey, as you said with your 135 oil leaking onto the clutch discs, were you talking about the clutch discs for the multipower or the main clutch? And is it possible in my condition now as I've described it for oil to get onto the main clutch and cause damage to it?

Thanks all!

Dan

Sounds like most of your problem is the main seals of the input shsfts and not the seal rings if it shifts solidly. Increased leakage may be due to increased temperature. Been six years since I had it tore down and dont have access to a parts breakdown but I do remember there is at least 1 rubber lipped seal in there. It seems the shafts the seal rings are on wear less than the bore they seal in.

Oil leaking on mine soaked the main clutch and replaced it with a complete rebuilt unit cheaper than the parts to rebuild it myself. The clutch discs on yours are likely oil soaked already and worn to a point that you should replace them while you have it split.

I believe on the 135 the original shafts and bores where the seal rings are located are no longer availble but a new design is at a high cost.