IH Cub - Weak Hydraulics

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doubleoc

New member
Howdy, I've got a 1970s IH Cub gifted to me by some relatives that has frozen hydraulics. I recently bought the pump rebuild kit and the touch control rebuild kit and rebuilt both. I made sure to clean the internals of the touch controls pretty well since there was a lot of gunk inside. I've gotten everything hooked back up on the tractor and filled the TC with SAE 30 oil with the cylinder fully retracted as to not overfill it.

Initially I tested the tractor with no weight or implements attached. When I turn the tractor on and push the TC level forward (towards the gas tank) the cylinder extends at a normal speed (compared to the videos I've seen online). The problem I'm facing is when I pull the level back towards the seat, the cylinder retracts extremely slow even without a load. I'm estimating almost a minute to it to fully retract at idle, is this normal?

With this tractor I received a front mounted snow plow and when I hook it to the rocker arms on the hydraulics, the pump struggles to lift the blade up. I can manually lift the blade up and the cylinder will stay in place but when I lower the blade with the TC it's very jerky.

Anyone have any similar issues or suggestions?
 
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Welcome to the forum! Might be that your 30wt oil is part of the problem. The Cub TC system spec is for Case-IH Hytran or a compatible fluid. You have to cycle the hydraulics 15 or 20 times with the fill cap off to get the air out of the system. Check the HOW TO forum for some tips. Double check that you used the correct rebuild kit for the TC. There's 2 different ones based on the TC part number. JMHO Stan
 
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staninlowerAL said:
Welcome to the forum! Might be that your 30wt oil is part of the problem. The Cub TC system spec is for Case-IH Hytran or a compatible fluid. You have to cycle the hydraulics 15 or 20 times with the fill cap off to get the air out of the system. Check the HOW TO forum for some tips. Double check that you used the correct rebuild kit for the TC. There's 2 different ones based on the TC part number. JMHO Stan
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Thanks Stan, I've read mixed reviews on 30wt oil vs hydraulic fluid like HyTran in the discussions here but I can try a traditional hydraulic fluid next. Initially I used the 30wt in case the pump seal was leaking.

I did do quite a bit of reading here and applied most of it, including the hydraulics cycling to bleed air. I believe I got the right kit from Steiner but I'm hoping to not have to tear it all back apart if I can help it.
 
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Hi,
The Touch Control uses thin fluid, they have said on here to not use motor oil in a Touch Control.
I would drain out the motor oil, using the small drain plug on the right side of the unit, and fill it with Case Hy-Tran fluid.
Case IH Hy-Tran fluid is thin, and made for Cub Touch Controls. There are other brands, be sure it works with IH hydraulic systems before buying it.
The Cub operator's manual says move the arms through their full travel 10 - 12 times, to remove the air from the system.
Below is a page from a Cub operator's manual telling how to fill the system. It was made before it was called Hy-Tran fluid. The Hy-Tran fluid is made for the transmission, and final drives of the newer Cubs too.
Be sure to fill it the last time with the arms in the rear or down position.
https://farmallcub.club/rudi/farmallcub.com/rudi_cub/www.cleancomputes.com/Cub/Cub Owner's Manuals/McCormick Farmall Cub Operator's Manual 12-20-55/Page 64.jpg

The Cub Touch Controls I have seen work slower going to rear or down position, than going up.
One expert on here has said that it so the system doesn't drop heavy implements so fast when you are lowering them.
It shouldn't work as slow as yours, going to down.
The owner's manual for a car I have says to not use 30 weight motor oil below 40 degrees, that company thought it's too thick for cold temperatures, I guess.
I have put part of a quart of 30 weight motor oil in my freezer, and let it get cold, it would barely run out of the bottle when cold.
 
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doubleoc said:
Thanks Stan, I've read mixed reviews on 30wt oil vs hydraulic fluid like HyTran in the discussions here but I can try a traditional hydraulic fluid next. Initially I used the 30wt in case the pump seal was leaking.

I did do quite a bit of reading here and applied most of it, including the hydraulics cycling to bleed air. I believe I got the right kit from Steiner but I'm hoping to not have to tear it all back apart if I can help it.
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When the Cub hydraulics was first available I believe the spec was for 30 wt non detergent oil but that was changed pretty soon to a thinner fluid. Your choice of course but I would suggest one of the aftermarket compatibles that's available at some auto parts sellers and some farm supply stores. I think the price is about the same. The HY Tran might be a little more expensive and of course probably have to get it from a Case IH dealer. Stan
 
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Hi,
Stan, the 1949 Cub owner's manual says to use 10W motor oil in the Touch Control.
The 1950 owner's manual says to use Touch Control fluid, which I think Jim B. has said was newly developed then.
In the later 1950's, Hy-Tran fluid was first mentioned in the operator's manuals.
I think Jim said that motor oil has the wrong additives in it for the Touch Control o rings. If that is not what he said, he will probably say. :) 🎄
 
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Glen said:
Hi,
Stan, the 1949 Cub owner's manual says to use 10W motor oil in the Touch Control.
The 1950 owner's manual says to use Touch Control fluid, which I think Jim B. has said was newly developed then.
In the later 1950's, Hy-Tran fluid was first mentioned in the operator's manuals.
I think Jim said that motor oil has the wrong additives in it for the Touch Control o rings. If that is not what he said, he will probably say. :) 🎄
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Glen, you're right. I didn't check, just going from memory (probably a bad idea at 82!) I guess I got the motor oil/ND right. As for the additives part, I remembered something else was needed but again just didn't get it all together. Sorry. :)
 
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The big picture here is complicated. But I think I have most of it right.

The original oil call-out was for 10W. It had been just fine in the earlier hydraulic systems like the Lift-All on an H or M. But the Touch-Control system is a much higher-tech design. It uses a closed center valve with a pressure control valve and all the related bits. Proper function depends on flow through a metered orifice. So the oil viscosity needs to stay in range. Additionally, air bubbles trapped in the oil will cause control problems along with the spongy behavior occasionally seen at the rockshaft.

Non-detergent motor oil is getting hard to find, particularly in a 10W. Detergent additives in motor oil cause foaming. So they have another additive to reduce foaming. The main contaminants motor oil has to deal with are products of combustion. There shouldn't be any of those in the hydraulic system. Modern hydraulic oils also have detergents and anti-foaming additives. The actual detergents used may be quite different. I believe the proportions are totally different than for motor oil, with more emphasis on anti-foam than on detergents.

An additional note on cold weather problems: If there is enough moisture in the oil for it to precipitate out (gather in the low spots), ice crystals can form and cause blockages until they melt. Most of us are aware that a plugged orifice (accessible through the pipe plug hole in the head) can cause the whole Touch-Control to shut down. Plugged with ice can shut it down just as easily as can any other junk that gets in there.
 
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Alright so I’ve drained the SAE 30 and filled it back up with a HyTran equivalent from Napa and results have not changed.

I’m thinking I have a small air leak in the hydraulic lines because when I drained the SAE 30 there were quite a few air bubbles in the fluid. There’s no visible leaks from the pump or the TC but there is a small whine near the center of the lines near the oil dipstick. Sounds like it’s time to buy a used set of lines from somewhere.

I’ve also noticed when running the hydraulics, there is no strain put on the engine like I’ve seen in a lot of videos of Cubs using hydraulics.
 
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The bubbles may be from the fact that the SAE30 has no anti-foaming additives. Did you cycle the control a dozen or more times with the engine running and the fill plug loosened?
 
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My thinking is leaning toward something that happened during the two rebuilds. The thin, flat figure eight shaped spring in the pump can easily be installed upside down. Others may have additional suggestions.
 
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Copy, I may have to take it apart and double check. I remember putting the spring with the flat side against the o-ring and thin seal (with the prongs facing up towards the brass pieces) like I saw in a couple of rebuild videos. The pump doesn't leak at all and does push fluid, I had to remove the high pressure small allen key on the side of the TC to release an air bubble and a ton of fluid pumped out.
 
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Another thing in the Cub Touch Control pump is the Pin Seal. It is small, and if left out, they have said on here the pump won't work right. Only some of the pumps have it.
Below is a listing at TM Tractor Parts for the Case IH pump repair kit.
It tells which pumps use the pin seal in the lower 2 pages of the directions. You use the makers model number of the pump to identify if it uses the pin seal. The number is stamped on the outside of the pump.
The IH part number is on the pump too, it isn't used to identify if the pin seal is used.
The pin seal is number 7 in the parts picture. :) 🎄
 
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Glen said:
Another thing in the Cub Touch Control pump is the Pin Seal. It is small, and if left out, they have said on here the pump won't work right. Only some of the pumps have it.
Below is a listing at TM Tractor Parts for the Case IH pump repair kit.
It tells which pumps use the pin seal in the lower 2 pages of the directions. You use the makers model number of the pump to identify if it uses the pin seal. The number is stamped on the outside of the pump.
The IH part number is on the pump too, it isn't used to identify if the pin seal is used.
The pin seal is number 7 in the parts picture. :) 🎄
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Thanks Glen, I do remember fighting with that little guy to get it all settled in properly. I’ll take a look once I take the pump apart again.
 
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