Fiat Allis 10C with transmission oil transferring to the backend

[bravo-harris]

I'm trying to find a solution: Fiat Allis 10 C's transmission oil being transferred to backend. I've tried by replacing o-rings and the seal from the transmission to the backend. I've been looking at the system and I can't see any leakage at all, so I believe is located somewhere else and can't figure out where, but it is pumping over. I see the oil lowering in the transmission and increasing in the backend. Help on this will be valuable. Thanks.

 

[Queenslander]

Not sure about the 10, but the 14 has two pumps doubled up.
One for transmission and the other for the steering clutch/brake circuit.
The seal between the two pumps can fail, transferring oil one way or the other.

 

[Dugandan]

Hello Bravo Harris and Queenslander, I have a Fiat-Allis 10-C about 1980 model. As far the hydraulic pump configuration goes, this is what I understand from looking at the manuals and my 10-C. It may not be any help to the problem, but for what it's worth, here goes...

There are a total of 3 independent hydraulic pumps, all located at the rear of (either) the master clutch or torque converter housing.

1. The big pump directly under your left foot as you sit in the operator's seat is the equipment pump, servicing the blade and ripper hydraulics. It is the largest of the three.

2. The pump directly under your right foot as you sit in the operator's seat is a twin section pump, both sections contained in one pump housing. The "front" section (closest to the front of the machine) is for the transmission charging pump, and the "rear" section is a scavenging pump, which picks up oil from the bottom of the torque converter or master clutch housing and puts it into the transmission sump.

3. The pump sitting more or less between the above two, but also more or less under the equipment pump and thus also indirectly under your left foot is the steering brake and clutch pump..

 

[Queenslander]

G’Day Dugandan, I realise that it is probably pointless comparing two different machines, but just as a matter of interest, the 14 (with power shift and TC), actually has two double pumps.
The steering clutch pump is coupled with the scavenge pump.
We once had the same problem that the OP has and ended up replacing the pump as we were fitting a reconditioned transmission at the same time.

 

[Dugandan]

Hello again Bravo Harris and Queenslander,
Bravo Harris, if yours is the torque converter model then just disregard my previous ramblings.
The pump set up information in my previous post for the master clutch model. If it is the torque converter model it will have the two twin section pumps as Queenslander has said. Hope you find your problem, please follow Queenslander's guidance.
Here is a diagram from the manual.

 

[Queenslander]

Don’t worry, I’ve been down the same track myself.
My book shows two different schematics for the TC/ gearbox hydraulic system.
Your diagram looks to be identical to the 14.

 

[bravo-harris]

Thanks guys. The tandem pump is brand new.We have had this problem for two years and four mechanics later.Transmission was removed and rear seal changed.

 

[bravo-harris]

We have removed the armour plate under the transmission. It takes two hours of pushing work to empty the transmission and find the oil level in the back end well over the maximum mark.Sitting in the Tractor below your left foot is the large Hydraulic pump and just below and to the right is the two part new Tandem pump. Your thoughts

 

[Queenslander]

That is the correct pump.
That’s a lot of oil to be loosing, and as far as I can work out, the pump is the only place that the two systems link hydraulically.
Did the seal look ok on the old one?
Our tractor wasn’t leaking anything like that but I still found a small crack in the seal.
Where do you source your parts?
On the 14 there are two voids in the casting in the back end, one on either side, each with a bung, the book says to drain them now and then.
Could be worth investigating to see what is happening there.

 

[bravo-harris]

We source our parts in the us,Canada and Italy.also have a FL 14 B Track Loader.I wonder if we drain the oil in back end and start the machine with middle back end cover plate with filter open if we will see the oil leaking into the back end.?

 

[Queenslander]

That should work, just remove the cover over the return filter to start with.
With the amount of oil involved it should be easy enough to pick up.

 

[bravo-harris]

Thanks for the help.We are now cleaning up the area and repairing minor leaks and checking hoses before opening up the back end.There is third pump below your right foot.

 

[bravo-harris]

Hello Bravo Harris and Queenslander, I have a Fiat-Allis 10-C about 1980 model. As far the hydraulic pump configuration goes, this is what I understand from looking at the manuals and my 10-C. It may not be any help to the problem, but for what it's worth, here goes...

There are a total of 3 independent hydraulic pumps, all located at the rear of (either) the master clutch or torque converter housing.

1. The big pump directly under your left foot as you sit in the operator's seat is the equipment pump, servicing the blade and ripper hydraulics. It is the largest of the three.

2. The pump directly under your right foot as you sit in the operator's seat is a twin section pump, both sections contained in one pump housing. The "front" section (closest to the front of the machine) is for the transmission charging pump, and the "rear" section is a scavenging pump, which picks up oil from the bottom of the torque converter or master clutch housing and puts it into the transmission sump.

3. The pump sitting more or less between the above two, but also more or less under the equipment pump and thus also indirectly under your left foot is the steering brake and clutch pump..

Hello again Bravo Harris and Queenslander,
Bravo Harris, if yours is the torque converter model then just disregard my previous ramblings.
The pump set up information in my previous post for the master clutch model. If it is the torque converter model it will have the two twin section pumps as Queenslander has said. Hope you find your problem, please follow Queenslander's guidance.
Here is a diagram from the manual.

Thanks Dugandan. Kindly send scanned pdf of the schematic oil flow from the steering and brake pump. Thanks in advance.

 

[Queenslander]

The pumps on the right are both for the torque converter and transmission, the upper pair on Dugundan’s diagram.

 

[Dugandan]

Hello Bravo-Harris and Queenslander,
Schematic of 10-C Steering Brake and Clutch Hydraulics.

 

[DMiller]

I would be seriously digging for screens in the sumps or a blocked line or even a collapsed(Internally blistered) line not allowing return oil to move. The scavenge side of most Allis even the FA models pulled off the finals and another section off the trans case back to a common sump for suction of supply pump to systems.

 

[Queenslander]

Yes, I was going to suggest that while bravo-harris has the oil out of the back end, that he thoroughly check the suction lines and screen of the steering clutch pump.
What I know about about the principles of hydraulic theory could be carved into the back of a postage stamp with a pick axe.... but if there was a total blockage of the sc pump suction side, would it be possible for the pump to draw oil through the seal between the two pumps?

Pf is sc pump, Pr is scavenge pump.

 

[DMiller]

One other item just rang up, Vents on housings, one sump develops pressure above the other it will force feed to that one. ALL the vents blocked up and strainers debris loaded as well two lines on my 7G were hosed up. My little unit draws from left side bevel gear housing and from the bottom of the Trans housing sends that oil to a secondary sump with its own strainer where the Tandem pump draws suction on the other half feeds it to Trans control and the Steering pump takes suction from there as well. Steering clutch housing areas drain back to main reservoir, trans and steering Open Center dumps are back to Bevel and trans housings. My bevel housing would pressurize to force the oil into the clutch areas and slowly begin to starve the tandem trans pump. Is also a cooler on this unit it as well could be low pressure dumping back to res. where cannot control that flow.

 

[Dugandan]

Hello Bravo-Harris, Queenslander & DMiller,

Not sure how you are going Bravo Harris, but hope the attached is of some help.

I stumbled on a troubleshooting list in the Fiat Allis 10-C Service Manual (see attached, Fault number 12) which pretty much lines up with your description of the problem. The suggested causes are bang on the advice from Queenslander and DMiller.

As the Scavenge Pump Inlet filter (Fr) is not easy to find, I crawled under my 10-C and took a photo (red arrow points to 24mm bolt to undo) in case you have not located it yet. There are 5 screens/filters in total, 3 on the Transmission / Torque Converter circuit, and two on the Steering Brake and Clutch circuit.

Coincidentally, my machine also has had a blocked oil line, again as pointed out as a possibility by Q & DM. The blocked line supplied the engine oil pressure gauge on the dash. Luke, the mechanic who is helping me, suggested we try cleaning the line out with compressed air, it solved the problem in spectacular fashion.

Hope you can solve your problem, admittedly a bit more serious than mine, as easily.

 

[bravo-harris]

Thanks.Planning to work on the machine tomorrow and will advise.Also looking for a pair of second hand Tracks for a Fiat Allis FL14B Track Loader-badly worn track bushings.