Case 380CK Loader Hydraulics

[cbattles]

In general, I'm fairly new to tractors - and I'm even newer to this Case 380CK Loader/Landscaper, so any feedback at all would be appreciated...

Since I picked this tractor up, for the loader to function at all (even with just an empty bucket), it needs to be running at about 1000+ RPM. To lift the front end of the tractor, or handle a bucket with some dirt in it with any sort of reasonable speed, 1800+ RPM. Even at full RPM, it seems weak, although it has done everything I've asked it to so far.

I haven't notice any leaks, etc.

It doesn't seem like this would be normal. Any advice that you can give me on troubleshooting, would be appreciated. Could this be anything other than a pump?

Thanks

 

[cbattles]

Oh, let me also specify that I have removed and replaced the filter for the loader hydraulics.

I have a full service manual and parts manual, I just need some help on the troubleshooting side...

Thanks

 

[J_J]

Try pushing down on your 3pt lever . The 3pt should not move with a little downward push. This takes it out of bypass mode.

Your FEL should perform better. If not, then track down other troubles. Check the PRV for correct pressure.

 

[cbattles]

Try pushing down on your 3pt lever . The 3pt should not move with a little downward push. This takes it out of bypass mode.

Your FEL should perform better. If not, then track down other troubles. Check the PRV for correct pressure.

Thanks - but this tractor has separate hydraulic systems for the loader than the 3 pt, plus I have a 600 lb box blade hanging on the 3 pt right now.

By PRV, I'm assuming relief valve (?), it seems that if the relief valve was letting off too much pressure, it would act the same without regard to engine RPM.

I'm just making guesses here though, I'm open to some education if I'm not thinking about it correctly...

 

[J_J]

Are you saying that the FEL has it's own pump, and the 3pt has it's own pump?

If there is one pump, then the fluid would pass from the pump to the FEL valve which has system PRV. If the FEL valve has PB, then the fluid supply is sent out the FEL PB port to the input to the 3pt. If no valve is activated, the fluid just flows from pump through all the valves, and out the 3pt to tank. If the FEL valve is used, it takes some or all the fluid for the FEL operation. If the FEL is not using all the fluid, then the 3pt can use whatever is left over. If you stop using the FEL, then all the pump fluid is available for the 3pt. If you pull the 3pt lever up all the way, you are bypassing the fluid to tank through an orifice, which might provide some back pressure to the FEL. If the 3pt lever is pulled up all the way, the flow for all ofthe pump flow is trying to go through this passage, and will probably heat up the fluid if the process is continued. So in using the FEL with the 3pt lever in the full up position, the FEL can not pass all the fluid through the 3pt open center portion of the valve.
Now, lower the 3pt lever a little for open center operation, and all the pump fluid can flow through the 3pt valve unimpeded. Everything should now work normally. If there are still problems, then further trouble shooting is necessary.

The only way a relief valve will let of pressure is when the load provides enough resistance over the PRV setting, or you are forcing the cyl to the max position. Otherwise, this is something you are doing.

Have you noticed when picking up a very load the PRV will whine. This is telling you the load is to great. You can usually hear the PRV going off. Similar to the Power Steering sound when you turn the steering all the way to the stops.

 

[cbattles]

Are you saying that the FEL has it's own pump, and the 3pt has it's own pump?

Yes. The 3pt pump is in the transmission. The loader pump is driven by the crank and has its own reservoir.

If that's not complicated enough, there's a 3rd pump and reservoir for the power steering :confused2:

 

[DJ54]

You may want to look at the relief valve in the loader control. Should be on the front side of the valve body, left side. Check your manual to make sure. If it's not sticking, or gunked up, you could always do a pressure check, if you have the proper set up. Our local hydraulic shop set me up with a suitable glycerin filled pressure gauge, needle valve, and hoses for about $75 to $100. I, and select others have used it enough times, to pay for itself... If you have little or no pressure, it's either a stuck relief valve, not getting ample oil to the pump, or the pump is shot.

Does it have the single, or dual hyd reservoirs..?? What condition was the filter in when you removed it..?? Notice any filings, or metal particles..??

I have a 480C, and have to say the hydraulics on it are just pretty awesome... Takes a light touch on the control, and took a while to learn to feather it. So when properly working, they work great...

If you have the OEM manual for it, they are pretty thorough, and should have a trouble shooting section...

There are no o-rings on the spools to let it leak by internally, only on the ends to seal them up.

I had a '59 310B, with original pump. It had not had the best of care, but the pump still worked great. Unless it has been abused, or a lot of water and dirt through the pump, I would like to guess it may be the relief valve stuck, or supply/suction line closing up internally. Sometimes a little piece of something can get stuck in the seat, and hold the relief valve open.

#1. I would check to see that you are getting an adequate supply of oil to the pump. Possibly a collapsed suction line..?? If the filter was really nasty, it may have caused it to suck the inner lining together.

#2 Presure relief valve in the loader control.

#3 Pump pressure check.

Hopefully it is something simple like #1 or #2... Check the easy stuff first...

 

[cbattles]

Thanks for the info...

Does it have the single, or dual hyd reservoirs..?? What condition was the filter in when you removed it..?? Notice any filings, or metal particles..??

It has a single reservoir for the loader hydraulics. The previous owner apparently scrapped most of the filter. Literally the outer case and paper elements were ripped out and just the inner case was left. No telling what it was like before that.

I have a 480C, and have to say the hydraulics on it are just pretty awesome... Takes a light touch on the control, and took a while to learn to feather it. So when properly working, they work great...

I have to spend some time going through the control assembly anyway. It seems like the bushings are shot or it has the wrong size bolts holding the handles on or something. There's about an inch (at least) of play in the levers (just the lever) before the valve is even being operated. They also seem touchy in terms of where in the travel they like to work the best - there's position in the travel that things seem to work best and before and after that position they just don't. I'm not sure if that's because everything is kind of gunked up or not...

If you have the OEM manual for it, they are pretty thorough, and should have a trouble shooting section...

I must have missed that, do you mean in the operator's manual or in the service manual? I have both, but I didn't really see a troubleshooting section...

 

[J_J]

If you have the loader manual, then you should know what the loader is capable of, as in how much it can lift. If it can't lift the specified load, then the first thing would be to check the relief valve. Reset if necessary. Can you make the loader go into relief. Loader cyl might be leaking.

 

[cbattles]

If you have the loader manual, then you should know what the loader is capable of, as in how much it can lift. If it can't lift the specified load, then the first thing would be to check the relief valve. Reset if necessary. Can you make the loader go into relief. Loader cyl might be leaking.

It's rated to 2500 lbs. So far I haven't tried to lift anything that it wouldn't lift, but I also know that I haven't tried to lift anything yet that would have maxed it out.

I'm going to take take apart and clean the entire control assembly (including relief valve) this weekend to make sure that it's all correct and go from there.

Thanks

 

[J_J]

I would recommend that you not take anything apart until you check the relief pressure.

Now, if you think the loader is slow, it is the volume of fluid that dictates the speed of operation.

Increase tractor rpm for max hyd speed on equipment

 

[cbattles]

Now, if you think the loader is slow, it is the volume of fluid that dictates the speed of operation.

Increase tractor rpm for max hyd speed on equipment

So essentially, if everything is working properly, the engine RPM should have no impact on the lifting capability, only the lifting speed?

 

[J_J]

Once the hyd pump is turning, the fluid has to go somewhere. You will have fluid flow if the pump is turning, and there is enough fluid at the input of the pump. Any pressure you see is caused by some resistance to the flow such as a cyl,, or hyd motor. The more resistance, the more pressure, until the pressure is relieved to protect the hyd system.

A worn pump or leaking hyd system, will not build up the specified pressure.

 

[DJ54]

Trouble shooting would be in the service manual. Each component section has it's own trouble shooting guide. Should be listed in the table of contents, at the front of each section.

I glanced at mine, while back at the shop. One of the items asked if both circuits seem to be slow, or just one. ie: Lift and bucket tilt, or just one of them. Causes listed, relief or check valve in the control stuck, or something holding it open, or a loose connection on the inlet side of the pump, causing it to suck air. Don't know if your reservoir has the little sight glass like mine, for oil level, but does the oil look foamy, milky, etc..?? If it appears to be foamy, may be sucking air at the rubber section connection.

Does it feel jerky, like it's lacking supply of oil.., sucking air? Or just smooth and slow...??

If you have the factory manual, the hydraulic trouble shooting guide should be in there, in that section. If not, I'd be glad to copy mine, and email to you, when I get a minute to do so...

 

[cbattles]

Don't know if your reservoir has the little sight glass like mine, for oil level, but does the oil look foamy, milky, etc..?? If it appears to be foamy, may be sucking air at the rubber section connection.

I don't know if I have a sight glass or not, I don't remember seeing one, but I'll check it out.

Does it feel jerky, like it's lacking supply of oil.., sucking air? Or just smooth and slow...??

It's definitely not jerky. The rest of it is tough because I just picked this machine up recently, so I have no point of reference.

Peak horsepower on my diesel is at 2200 RPM. At 2000-2200 RPM, I would describe the loader tilt and lift as smooth and (at least relatively) fast -- at least with the exception of some issues with the controls themselves being somewhat quirky.

However, at idle (say 600 RPM) the loader won't lift or tilt itself empty - not just slow, i mean literally it really won't move but maybe a few inches total. It gets progressively more powerful and faster as RPM increases.

For all I know, this could be 100% normal - but for some reason suspect that it's not - and I can't find anything to tell me otherwise.

 

[cbattles]

For all I know, this could be 100% normal - but for some reason suspect that it's not - and I can't find anything to tell me otherwise.

To add to this, if I was the type to just assume stuff was working correctly, I'd just rev up the engine and get on with my day. However, since I plan to have this kicking around for a while, I'd rather make sure it's correct before I beat on it. :thumbsup:

 

[DJ54]

Mine will easily lift itself off the ground at an idle.

Since it is not jerky, it may not be sucking air, but then who knows. With the filter in shambles, I'd suspect something in the valve body, and hopefully did not damage the pump.

My whole unit is all still good and tight. I consider myself lucky to find this '79 model with 2115 hours showing on the hour meter when I bought it. Both tach and hour meter work, and are original, from the looks of things.

Did you find the trouble shooting section in your manual..??

 

[cbattles]

Thanks, yeah, that's about the same number of hours as mine - but it seems to have treated the unit entirely differently. I'm just glad I picked it up on the cheap. :laughing:

Haven't had a chance to check the manual yet, but I'm sure I just skipped over it somehow.

I plan on changing the fluid, putting another new filter in it, and cleaning the valve body. Hopefully that will clear up some of the issue.

 

[J_J]

cbattles,

You have not mentioned the hyd pressure yet. That will give you the first clue if anything is wrong. Maybe someone put restrictors in the circuit.

 

[J_J]

Install a hyd gage and check the relief pressure. With no lever activated, you probably will not see any pressure, or very little, If the valve spools are good, the fluid will flow into the cyl and the gage will show how much pressure the system has at that moment. Engage the lift lever to max, and you should see the relief pressure. If it is correct, then you have other problems.

If a hyd system can produce up to the relief pressure, then the hyd system should lift the specified load. That is also assuming that the cyl are good also.