Farmall model H hydraulic problems

[Drifter52]

Just bought a farmall H and on the way home it boiled over on the hydraulic tank. I had to road it for about 15 mile. The previous owner did an add on pump for all the hydraulics and with the mix of galvinized fitings and tees in the lines I am thinking it needs redone so I know it is right. I used to work on rock drills in the mine but am sure it has progressed beyound what I knew back then.

I am not even sure of the type pump that he put onto it. I am not sure even if the valves are open or closed center. Iam wondering if it isn't doing abypass all the time is why it is getting that hot.

tank and pump

Pump

valve body

Sure has me scratching my head. I have a 13 GPM pump I bought to power a woodsplitter with I was thinking of replacing this pump with. I am looking to run FEL,3PH an a remote for a log spliter.

 

[art]

I'd never recommend a forty horsepower engine to run where a 5 to 8 horsepower would do the same.

A farmall H with a loader and narrow front is dangerous! No power steering makes it even more of a bear!!!!

Coould have had a lot of condensation in the oil do the same.

 

[oldnslo]

Galvanized fittings and hydraulics do not mix. The oil will erode the galvanizing off of the fittings and contaminate every in the system.

Looking at the picture of the pump is there two pressure lines or does the smaller line return to tank? If they are both pressure lines the pump must have a priority flow valve and both of these lines must be connected to an open center circuit or they will cause heat generation.


Good Luck

Roy

 

[Drifter52]

It is my guess that they are both pressure lines. I know it did get hot enough during the road trip to push out a lot of oil. I just got this tractor for the purpose to cut wood and power the spliter as I didn't want to drag more pieces to the timber then needed.

I want to set this up right so my question would be what pump and valve setup will I need to feed a FEL,3PH and a remote for the log spliter? I don't believe the pump on there is big enough for my needs. I have no idea the history of the pump or valves and don't want to do it haphazzardly and end up redoing it.

 

[oldnslo]

Drifter,
pump size would be decided by the size of cylinders you want to operate and how fast you want them to move. Since I presume this will be driven by the engine HP to certain extent should not be an issue.

I do not know what the "factory" pump size was on an "H" or if these only came with add on hydraulics.

My best guess would be in the 6-9 GPM range but that is just a guess. I think our 5,000 Ford had a 9 GPM pump and it would operate every piece of equipment I hooked to it just fine.

Roy

 

[Farmerford]

Drifter 52:

The first tractor I remember driving was a Farmall H that my father bought on the black market when he returned from the Air Corps at the end of WWII. It had a home made front-end loader (I recall some parts were wood) and I don't recall turning it over or that it was hard to steer, but I was only ten or so years old at the time, so my memory is not the best. Your picture reminds me that the only plastic on those machines were the gearshift knob and steering wheel.

Anyhow, your problem may be a combination of too much heat and too little dissipation. Let me make some assumptions: pump is 8 gpm, lines are 1/2", and the pump body, pump lines, directional control valve, and reservoir hold 4 gallons. At 8gpm the 4g of fluid circulates two times per minute.

The pump appears to be a single section gear pump with a flow divider on the output, which is either a priority flow divider or a proportional divider. One output appears to return to directly to the reservoir. Depending on how the output is directed, the flow divider can cause the pressure drop in the line going from pump to reservoir (tank) to be the same as the pressure drop in the entire flow path for the other pump output stream.

The next part is really guessing (as if the above were not). Say the path through which the other pump output flows consists of 2 10 foot sections of 1/2" hose with fittings and a regular (or mitered) 90 deg elbow on each end, together with a variety of nipples, etc. The flow path also includes the flow divider which almost certainly imposes a significant pressure loss, and the directional control valve which has its own significant pressure losses.

These pressure losses can add up to more than you expect. For example, 10gpm of typical warm (90-100deg f) hydraulic fluid flowing through 10 feet of 1/2" hose with end fittings and an elbow on each end incurs a pressure loss of about 30 psi (that's the only number I can remember from a recent project).

Fors the sake of argument, assume that the accumlated pressure losses in the circuit are 140 psi (I suspect it is more than that). Since the flow divider on the pump probably imposes that same pressure loss on the flow into the reservoir, the full 8gpm incurs a pressure loss of 140 psi.

A rule of thumb (scientifically based) is that the temperature of typical hydraulic fluid increases 1 deg F for every 140 psi of pressure drop that is due to friction (and all these losses are due to friction, not to doing work by moving a piston in a cylinder). So, if you fluid passes through the system twice each minute, the temperature of the fluid increases by 2 deg F per minute.

If your 15 mile trip took an hour (I recall a maximum road speed of roughly that), the hydraulic fluid circulated 120 times and its temperature was raised 120 deg F above ambient temperature. If ambient temperature was 90deg F, the fluid temperature would have increased to 210 deg F.

Of course all that energy from the friction does not remain in the fluid; some passes into the hoses, fittings, pump body, etc. But once those parts heat up the only additional heat they absorb is what they radiate into the surroundings. If those surroundings are also hot, and if the sun is adding more heat to them, they may remove very little heat.

And if any of my assumptions are too low (the pump is 8 gpm rather than 12), the heat increase is much greater (more than just a proportional 150% in this case).

Of course, you could have a fully blocked pump (deadhead), but I doubt it because the heat buildup then would be very fast. If the pressure relief valve is set at 1400 psi, the each time the fluid passes through the system the temperature rises by 10 deg F (1400/140 x 1), which is 20 deg F in this case. It would be boiling in 10-15 minutes in that case.

If it were me, I would remove the flow divider from the pump, combine both pump flows into the working circuit to the control valve rather than send one to the tank, clean up the hoses (new hoses, limit elbows, etc.), and replace the tank with a 10-15 gal one. I think there is a good chance that will solve your problem. If not, you will need the new hoses and tank for the 13 gpm pump anyway. Save the other pump because as long as those old cast iron Farmalls last it will wear out the current pump.


I hope Art is right about the H having 40 horsepower, but I recall it being somewhere around 30. Do you know?

Keep us posted on the project.

Good luck

 

[Drifter52]

Farmerford I gave a quick glance through the books he gave me but didn't see the rated HP. I can remember as a kid seeing several farmers around still using them to pull the grain wagons. Only saw a couple tipped over and they were usually doing something they knew better then as in mowing a steep bank.

Very informative on the information you have shared with me. I am looking forward to this adventure of getting this old gal into what will work better for me. I will ask a guy at work that grew up around them what the HP rate was. It will be Monday before I get a chance to do anything as I am working 12 hour shifts and even though too late I like my beauty rest.

I don't believe my valve is PB equiped so at the very least I am thinking a new valve is in order. I can take a picture of what is plumbed and make a diagram of how it is plumbed in so maybe someone can make heads from tails of what has been done.

By the book the belly pump can make 800 PSI at high idle and has a oil reserve capacity of 8 Gal. Doubt I will be using that feature.


Farmall H Power:
Drawbar (claimed): 17-19 hp [12.7 kW]

Belt (claimed): 21-24 hp [15.7 kW]

Drawbar (tested): 24.17 hp [18.0 kW]

Belt (tested): 26.20 hp [19.5 kW]



Drifter52

 

[J_J]

If the tractor has a HP rating around 30 HP, you could run a hyd pump, at 10 GPM's at 3000 psi, and use only 21 HP, or pump 14 GPM and use 29 HP.

At 2500 rpm, the pump displacement would be 1.3 cu in. and at 3000 rpm, would be 1.1 cu in,

 

[Drifter52]

The pump I have now is a 13 GPM double stage. Will this be an issue it being a double stage?

I am also assuming the way to plumb this is to use a 3 spool valve and the remote I want to the power beyond. I am also looking to make a bigger resivor tank of at least 20 gallon and adding an oil cooler.

Drifter52

 

[Drifter52]

https://www.surpluscenter.com/item.asp?item=9SV-3-Y&catname=

Would this be the right valve for my needs? What options would I have to select in the 3 sections on the drop down menu? I will be running the hoist, break out for bucket roll and 3PH on the main valve.

 

[J_J]

Using a 2 stage log splitter hyd pump for tractor hyd is not a good idea. It only pumps 13 GPM's at 650 psi. and 3 GPM's at 2500 psi. Those figures are with the tractor rpm at 3600.

 

[J_J]

https://www.surpluscenter.com/item.asp?item=9SV-3-Y&catname=

Would this be the right valve for my needs? What options would I have to select in the 3 sections on the drop down menu? I will be running the hoist, break out for bucket roll and 3PH on the main valve.

Power beyond, float, and for rear remote, maybe detent.

 

[300UGUY]

Farmerford I gave a quick glance through the books he gave me but didn't see the rated HP. I can remember as a kid seeing several farmers around still using them to pull the grain wagons. Only saw a couple tipped over and they were usually doing something they knew better then as in mowing a steep bank.

Very informative on the information you have shared with me. I am looking forward to this adventure of getting this old gal into what will work better for me. I will ask a guy at work that grew up around them what the HP rate was. It will be Monday before I get a chance to do anything as I am working 12 hour shifts and even though too late I like my beauty rest.

I don't believe my valve is PB equiped so at the very least I am thinking a new valve is in order. I can take a picture of what is plumbed and make a diagram of how it is plumbed in so maybe someone can make heads from tails of what has been done.

By the book the belly pump can make 800 PSI at high idle and has a oil reserve capacity of 8 Gal. Doubt I will be using that feature.


Farmall H Power:
Drawbar (claimed): 17-19 hp [12.7 kW]

Belt (claimed): 21-24 hp [15.7 kW]

Drawbar (tested): 24.17 hp [18.0 kW]

Belt (tested): 26.20 hp [19.5 kW]



Drifter52

Those hp numbers were from the 40's or early 50's. Most of thses tractors have been rebuilt at least once, and the rebuild kits generally gave you some more hp. I rebuilt my H, including the head, and I am getting around 35hp. Guys pulling these old girls regularly run them up a lot higher.

 

[Drifter52]

Far as I know she hasn't been rebuilt or used that much. More weathered from sitting ut then anything. Found an old PTO pump today. Wierd looking deal is all encased in about a 2 gallon canister that serves as the resevor. Took it apart to clean it up and turned by hand it pumps. Drives with a chain and appears to be a 1 to 1 ratio on the sprocket. Valve is built into th pump body with one mean return spring. Anyone had any dealings with them? Didn't see a brand name or label on it anywhere. Something was painted on the back end but is all weathered into oblivion.

Drifter52

 

[IceStationZebra]

If you aren't going to use the FEL I would run a pto pump. No belts to worry about, and if you want a different tractor no big deal.

Post of pick of your PTO pump. When I worked for CaseIH the big PTO pumps used on big corn planters were bolted rigid to the tractor with a custom bracket. To allow for some flex in the pump drive, there was an adapter that slid over the PTO shaft and attached to the pump with a double chain wrapped tight around both sprockets. Maybe this is what you have?
Heavy Duty Chain Coupling

ISZ

 

[Drifter52]

I measured the canister that contains the pump. Diameter is 9 in and is 10 in long. I figure it to be in and around 2 1/2 gallon but the pump inside will take up some of that. The drive was a single chain with a sprocket on the PTO and one on the pump from what I can see. And the pump mounted to the draw bar.

The lever is one stiff begger and spring return to center. Threads on top Ithink are 3/4 NPT but have been buggered up and a plug doesn.t want to start. The ring is aluminum. When I took it apart they had used silicone to try to seal it up and a lot was inside and some was stuck to the screen of th intake to the pump. The remains of a paper type gasket was in the recess of the ring as well with the silicone. The end had been mashed in some which I pounded out with a big hammer and a 2X2 block to somewhat where it should of been. 2 baffles were also inside which one was broke loose. One of the bolts had been over tightened and caved in part of the canister as well. I am thinking an Oring might be a better way to seal this and might have been what was used originally.

Drifter52