Ford CL40 / Eric 4850 Hydraulic question

[Steelart99]

I have an old Eric 4850 (same as Ford CL40) skid steer that has been re-powered with a Nissan B310 engine. It is definitely a 'hobby' machine with numerous little issues. I finally got the engine running (albeit roughly) and can drive it around. Lift and tilt work, but with some oil leakage in the valve assembly. Here is my current issue: When I drive the bucket lift on this, there is a stuttering in the movement. My guess is that one of the lift cylinders is not working or is dragging somehow. Is there a way to figure that out? In a parallel system, how do you tell if one cylinder is getting pressure? Might there be another problem that would cause this symptom? Since is does lift, I would assume that the lift valve is getting oil out to the lift cylinders. I have a little bit of hydraulics background, but not enough to be able to narrow down my issue here. Any help would be appreciated.

 

[Tazza]

I would doubt it is the cylinder, but i guess possible.
My first guess would be the hydraulic system has air in it or the pump is making the oil foam up due to wear.
The leaking valve block may be allowing air into the system too.
Is the oil in the reserve tank foamy after you use the machine?

 

[Steelart99]

I would doubt it is the cylinder, but i guess possible.
My first guess would be the hydraulic system has air in it or the pump is making the oil foam up due to wear.
The leaking valve block may be allowing air into the system too.
Is the oil in the reserve tank foamy after you use the machine?

I thought about air also and just tried cycling the cylinder multiple times thinking that would pull the air out. I didn't think about the valve letting 'more' air to be introduced! I have not checked the reserve tank, but will do so tomorrow to see if it is foaming. Good thoughts. Thanks

 

[Steelart99]

I would doubt it is the cylinder, but i guess possible.
My first guess would be the hydraulic system has air in it or the pump is making the oil foam up due to wear.
The leaking valve block may be allowing air into the system too.
Is the oil in the reserve tank foamy after you use the machine?

Well, I got this beast fired up and the oil was foaming up in the reservoir. The lift/tilt valve was also leaking at both control rods as I'd indicated. So, does anyone know of someone how could rebuild (new seals) on this valve? ? ? ? ? ? ? The skid steer is from the mid-70's and I pretty sure that re-build kits for the valves don't exist anymore ... at least I can't locate any. I suspect that most of the seals are just standard O-rings. However the two control rods appear to have cup shaped seals on both ends. I have no idea if these types of seals are standard or not. The manuals for this skid steer do go through the procedures for replacing all the seals. Here is the parts blowup: https://www.partspring.com/catalog/product/view/id/196543/s/cl40-872/category/301/

 

[Tazza]

Well, I got this beast fired up and the oil was foaming up in the reservoir. The lift/tilt valve was also leaking at both control rods as I'd indicated. So, does anyone know of someone how could rebuild (new seals) on this valve? ? ? ? ? ? ? The skid steer is from the mid-70's and I pretty sure that re-build kits for the valves don't exist anymore ... at least I can't locate any. I suspect that most of the seals are just standard O-rings. However the two control rods appear to have cup shaped seals on both ends. I have no idea if these types of seals are standard or not. The manuals for this skid steer do go through the procedures for replacing all the seals. Here is the parts blowup: https://www.partspring.com/catalog/product/view/id/196543/s/cl40-872/category/301/

Seals should be able to be matched at a seal shop. If you take the old ones in, even with the control block, they should be able to find you replacements.
A plugged filter could also cause oil to foam up. If the suction line is restricted, it can make the oil foam up.
The control block needs to be re-sealed, but may not fix all the foam if the pump is the issue.

 

[Steelart99]

Seals should be able to be matched at a seal shop. If you take the old ones in, even with the control block, they should be able to find you replacements.
A plugged filter could also cause oil to foam up. If the suction line is restricted, it can make the oil foam up.
The control block needs to be re-sealed, but may not fix all the foam if the pump is the issue.

I finally found a shop that is willing to see if they can find a set of seals that will work. I just realized that the somewhat low level of my hydraulic fluid might be causing some of my issues. There is a filter in the tank that has about the top 1" exposed (horizontal orientation). I was thinking this was the return line ... but maybe it is the suction line ??? 'shrug'. I'll pick up some fluid to fill the tank and give it another try. Thanks for the suggestions.

 

[Tazza]

I finally found a shop that is willing to see if they can find a set of seals that will work. I just realized that the somewhat low level of my hydraulic fluid might be causing some of my issues. There is a filter in the tank that has about the top 1" exposed (horizontal orientation). I was thinking this was the return line ... but maybe it is the suction line ??? 'shrug'. I'll pick up some fluid to fill the tank and give it another try. Thanks for the suggestions.

That sounds like what could be the issue.
I deal with a seal shop that is happy to match any seal you bring in to them, they don't get kits for anything, they measure the samples to know what ones are required, hopefully the place you found will do the same.