Hydraulic Oil weeps out of transmission fill hole

[Skeeter102]

When using my 8n I've noticed that i get some weeping out of the fill hole on the transmission cover from underneath the cap. I have also noticed that I will get hydraulic fade when the tractor is warm. The hydros aren't as responsive at idle when warm as they are when cold.

This is central Texas and its been in the 90's while running the tractor. I've mostly been using the box blade to build driveways.

The fluid is new, pump was dropped and cleaned, and all linkages are aligned properly using zane's jig. I have a new top cover gasket, and NAA lift piston with leather and rubber washer.

I am using traveller UTF that meets the 134D spec.

What's up with this?

 

[old]

UTF is a thin oil and in hot weather it will be very thin. Where you live I would use 90W oil because it a a lot thicker and will work better where hot

 

[Money Pit]

had a similar problem on my naa except it was the starter button weeping. confused me how oil could flow up. folks here pointed out all the spinning stuff in the tranny flings oil every direction. put some rtv around the starter button and no more problem. think you just have to get the filler cap sealed right. don't know if there is supposd to be a gasket in there?

 

[TheOldHokie]

(quoted from post at 23:09:06 09/28/15) When using my 8n I've noticed that i get some weeping out of the fill hole on the transmission cover from underneath the cap. I have also noticed that I will get hydraulic fade when the tractor is warm. The hydros aren't as responsive at idle when warm as they are when cold.

This is central Texas and its been in the 90's while running the tractor. I've mostly been using the box blade to build driveways.

The fluid is new, pump was dropped and cleaned, and all linkages are aligned properly using zane's jig. I have a new top cover gasket, and NAA lift piston with leather and rubber washer.

I am using traveller UTF that meets the 134D spec.

What's up with this?

Put a gasket on the filler. Please define what you mean by "hydraulic fade" and is this the tractor with live hydraulics conversion?

TOH

 

[Skeeter102]

Put a gasket on the filler. Please define what you mean by "hydraulic fade" and is this the tractor with live hydraulics conversion?

TOH

Yes this is the tractor with the live hydraulics conversion, shaft drive, front mounted pump.

After the tractor heats up, you have to use more throttle to get the hydraulics to respond. If you lift the quadrant lever, the hydraulics will not lift unless the tractor is above idle.

 

[TheOldHokie]

(quoted from post at 08:21:06 09/29/15)

Put a gasket on the filler. Please define what you mean by "hydraulic fade" and is this the tractor with live hydraulics conversion?

TOH

Yes this is the tractor with the live hydraulics conversion, shaft drive, front mounted pump.

After the tractor heats up, you have to use more throttle to get the hydraulics to respond. If you lift the quadrant lever, the hydraulics will not lift unless the tractor is above idle.

Is that with the internal (belly) pump also engaged or not? And does it not lift at all or does it simply take a while to start to lift and then lift slowly?

TOH

 

[ZANE]

Don't use 134 in hot climate. Unless you have one of my live hydraulic kits installed. :O)

Use 90W

What about the pressure relief valve???

 

[Skeeter102]

It would lift very slowly. I would have to engage the belly pump to get the hydraulics working at a usable rate.

I suspect that old is correct with the UTF just being too thin.

 

[TheOldHokie]

(quoted from post at 08:41:30 09/29/15)
It would lift very slowly. I would have to engage the belly pump to get the hydraulics working at a usable rate.

I suspect that old is correct with the UTF just being too thin.

I don't think your problem is oil related and I wouldn't switch to 90W gear oil with the front pump.

The displacement on your auxiliary pump is .25 cubic inches and the flow rate is 2 GPM @ 2000 RPM. At 500 RPM (idle) it is producing a scant .5 GPM which is just too little flow to quickly raise the lift without the additional flow from the internal pump. The fact that it works a little faster when cold suggests to me that you still have some leakage in the lift circuit. How long does it take for the lift to leak down when the tractor is turned off?

TOH

 

[souNdguy]

have you:

1, looked into the rear sump to see if you have any leaks you are having to overcome that may be eating your flow and possibly pressure?

2, put a pressure gauge and see what you are developing at cold idle, cold throttle, hot idle, hot throttle, with respect to relief pressures with the lift chained, and taking into account the presence or absence of leaks as in #1

 

[Skeeter102]

(quoted from post at 05:39:43 09/29/15)
Don't use 134 in hot climate. Unless you have one of my live hydraulic kits installed. :O)

Use 90W

What about the pressure relief valve???

Relief valve is new.

 

[Skeeter102]

(quoted from post at 05:57:07 09/29/15)

(quoted from post at 08:41:30 09/29/15)
It would lift very slowly. I would have to engage the belly pump to get the hydraulics working at a usable rate.

I suspect that old is correct with the UTF just being too thin.

I don't think your problem is oil related and I wouldn't switch to 90W gear oil with the front pump.

The displacement on your auxiliary pump is .25 cubic inches and the flow rate is 2 GPM @ 2000 RPM. At 500 RPM (idle) it is producing a scant .5 GPM which is just too little flow to quickly raise the lift without the additional flow from the internal pump. The fact that it works a little faster when cold suggests to me that you still have some leakage in the lift circuit. How long does it take for the lift to leak down when the tractor is turned off?

TOH

This is possible. I'll pop the side cover and take a look.

I wonder if i nicked the leather washer on install.

Might have some time to look into it sunday and report back .

 

[Richard G.]

Zane is right. Use GL1 90 wt at those temps. I use it year round and it can go from 0 to 100+ here.
Richard in NW SC

 

[TheOldHokie]

(quoted from post at 11:44:21 09/29/15)

(quoted from post at 05:57:07 09/29/15)

(quoted from post at 08:41:30 09/29/15)
It would lift very slowly. I would have to engage the belly pump to get the hydraulics working at a usable rate.

I suspect that old is correct with the UTF just being too thin.

I don't think your problem is oil related and I wouldn't switch to 90W gear oil with the front pump.

The displacement on your auxiliary pump is .25 cubic inches and the flow rate is 2 GPM @ 2000 RPM. At 500 RPM (idle) it is producing a scant .5 GPM which is just too little flow to quickly raise the lift without the additional flow from the internal pump. The fact that it works a little faster when cold suggests to me that you still have some leakage in the lift circuit. How long does it take for the lift to leak down when the tractor is turned off?

TOH

This is possible. I'll pop the side cover and take a look.

I wonder if i nicked the leather washer on install.

Might have some time to look into it sunday and report back .

Before you start tearing things apart check for leak down by fully raising the lift with your box blade on it, shutting the engine off, and timing how long it takes for the lift to drop to the ground. That is a major indicator of how much leakage you are getting in the lift circuit.

TOH

 

[Skeeter102]

I realized I never reported back on this.

I ended up finding a leak on the intake side of my front mounted pump. One of the JIC fittings got loose and was causing the pump to suck air. I tightened down the fitting and all is well.

Thanks for everyone's help.