Farmall Cub

If you don't have a diverter valve (on the tunnel) then both cylinders actuate at the same time. The heavier implement is the one that lifts last. Example: with a mid-mower deck attached and nothing on the 3-point, the 3-point lifts first and when it gets all the way to the top then the mower deck is lifted. Add a tiller to the 3-point and then the mower deck lifts first then the tiller is lifted.

There is something very wrong if you have to help lift the 3-point. The 3-point hitch can lift the front tires off the ground when attached to a heavy implement.

I sounds a lot like the hydraulic pump is drawing air rather than oil. Are you sure the transmission is filled to the proper level and that there are no leaks in the line from the transmission to the pump?

outdoors4evr wrote:If you don't have a diverter valve (on the tunnel) then both cylinders actuate at the same time. The heavier implement is the one that lifts last. Example: with a mid-mower deck attached and nothing on the 3-point, the 3-point lifts first and when it gets all the way to the top then the mower deck is lifted. Add a tiller to the 3-point and then the mower deck lifts first then the tiller is lifted.

There is something very wrong if you have to help lift the 3-point. The 3-point hitch can lift the front tires off the ground when attached to a heavy implement.

Yes, that I understand. I don't believe the deck cylinder should be an issue with it being stuck in position at the moment so there's really no need to lock it out yet. I agree something is wrong, think I read the 3pt should lift 500# or so.

Jim Becker wrote:I sounds a lot like the hydraulic pump is drawing air rather than oil. Are you sure the transmission is filled to the proper level and that there are no leaks in the line from the transmission to the pump?

Yes, the fluid runs out fill hole, and I checked it again after cycling the system for several days. There were a couple leaks from loose fittings when I first got it but I had went through and made sure everything was tight before changing the fluid. I haven't seen any leaks since. Could the pump be worn enough to be cavitating ? Or maybe pulling air through the control valve ?

FrankenCub wrote: Could the pump be worn enough to be cavitating ?

Not captivating since you get some pressure. However the pump has a diaphragm instead of an internal wear plate. Diaphragm may damaged and the hydraulic pump needs to be repaired.

Or maybe pulling air through the control valve ?

Control valve is on the pressure side of the hydraulic pump. So the answer is no. A leak at the control valve would squirt hydraulic fluid.

FrankenCub wrote: I'm slowly getting the 3pt to function somewhat, still gotta be a lot of air in the system and it seems to leak down quickly when it does finally raise with my help.

Purpose of the control valve is to direct fluid to the hydraulic cylinder, then hold the hydraulic cylinder(s) into position. Any air initially trapped into cylinders would be discharged with 2 or perhaps 3 cycles of the cylinders.

So, back to the problem(s). My first check would be the hydraulic pump to see if all the parts are intact and correctly installed. Second check would be the control valve and pressure relief valve.

Edit: Has the hydraulic every worked correctly since you owned the tractor? And has the hydraulic system previously been worked on?

Eugene wrote:Not captivating since you get some pressure. However the pump has a diaphragm instead of an internal wear plate. Diaphragm may damaged and the hydraulic pump needs to be repaired.

Control valve is on the pressure side of the hydraulic pump. So the answer is no. A leak at the control valve would squirt hydraulic fluid.



So, back to the problem(s). My first check would be the hydraulic pump to see if all the parts are intact and correctly installed. Second check would be the control valve and pressure relief valve.

Edit: Has the hydraulic every worked correctly since you owned the tractor? And has the hydraulic system previously been worked on?

According the the service manual this pump doesn't have the diaphragm, it has wear plates. It's the long Warner-Motive pump.
I should have thought more about the control valve, that should have been obvious
The hydraulics haven't worked right for me yet, I've only owned it a couple weeks or so. From what I can tell there are no signs that the hydraulics have been worked on either. The guy I bought it from only drove it around his yard a few times a year, he bought it from a friend who was in need of money, so I have no real idea of it's history.

Never had the pump apart on the numbered Cub Low-Boys. However, my parts manual, TC 131, only shows the diaphragm and no wear plate. My parts manual, GSS-1408, doesn't show an exploded view of the pump.

Back to the wear plate. Folks frequently get the wear plate installed backwards. Then the pump doesn't work properly.

Eugene wrote:Never had the pump apart on the numbered Cub Low-Boys. However, my parts manual, TC 131, only shows the diaphragm and no wear plate. My parts manual, GSS-1408, doesn't show an exploded view of the pump.

Back to the wear plate. Folks frequently get the wear plate installed backwards. Then the pump doesn't work properly.

I was looking at the I&T Shop Service Manual, No. IH-50. It shows two pumps availible, the Warner that I have and a Cessna. From the manual.."Sealing service package for the Warner-Motive pump consists of one gasket, three "0" rings, two wear plates and seal kit."
The Cessna pump.."To install diaphragm seal kit, proceed as follows".
I don't know much more about it though, not sure why they would offer two seperate pumps. The Warner is physically bigger than the Cessna pump so maybe it flows a little more, IDK.

If the front cylinder is stuck, full of air and connected without a selector valve to the rear cylinder, you will probably never get the air worked out of it to eliminate the sponginess at the rear. Unhook the front cylinder and cap the line.

Jim Becker wrote:If the front cylinder is stuck, full of air and connected without a selector valve to the rear cylinder, you will probably never get the air worked out of it to eliminate the sponginess at the rear. Unhook the front cylinder and cap the line.

I'll do that as soon as the weather clears, with all the rain the past few days I have 2" of water in my tractor shed :-/
I have also noticed there seems to be no sound of strain, like the pump is trying to build any pressure. I called my local Case/IH dealer and the overhaul kit for the pump is no longer available, they also checked their online locator with nothing showing at any dealer in the country. But, they do show a aftermarket replacement for over $300 by time I also buy the specified adaptor.
After I plug the center line and test the pressure I will look for a good used pump if need be. I also looked over the safety valve thinking it may have some dirt in it allowing it to bypass the pressure but was really clean.
Now just praying for the rain to go away, can't work on the 154, can't get any astro photography in. This just isn't right lol.

Ok, so a little update...I've been busy with other things concerning the 154 lately so haven't had chance to test the hydraulic pressure. Last night I checked the oil level before adding some Sea Foam and noticed it was quite high. Do these pumps leak into the crank case like the F-Cub pumps can ? If so it looks like I found my problem with no pressure lol

FrankenCub wrote:Do these pumps leak into the crank case like the F-Cub pumps can ?

Yup. I think you found the problem.

I got thinking some. Seems the on board pump is obviously an issue and I was going to add a pump just for the loader, why also plumb the on board hydraulics into that pump. Will be cheaper in the long run. Any ideas as to what size pump I should use ? The loader rams look to be 2.25 bore and 1.75 ram diameters. Or even a link to somewhere here where it's been discussed ? I've searched but haven't come up with one yet. A lot on the net but I kinda get a little confused with the way they get into it. The pump displacements also kinda make me wonder, I've looked at some pumps from Surplus Supply and the displacement looks so small to me, even for a 10gpm pump.

Hmmm......
10 gallon per min at what rpm?

jimthetravler wrote:Hmmm......
10 gallon per min at what rpm?

One of them is 9.5gpm at 1725rpm continuous, 1.3cu. in.
http://www.surpluscenter.com/item.asp?item=9-7733&catname=hydraulic
That is one of the cheaper pumps they have. I may swing by my friends junk yard and look around, he gets all sorts of industrial and farm equipment in. But problem there is I have no way of knowing if the pump will be close to the right size, benefit is it wouldn't cost me anything though lol.