L**40 rear hydaulic pressure

[J_J]

Kubo,
you willing to try a couple more simple tests?

1) Dump the bucket fully. Now as you are curling it back operate the rear remote.

Do you get pressure at the rear remote?

Did the bucket stop moving?

What I am trying to determine with this test is which way is the oil flowing. If you get pressure on the rear QD's and the bucket keeps moving then we have some more head scratching, darn near bald already Would indicate some form of flow divider before the FEL that is feeding flow to the rear remotes and this flow would not see the FEL relief.

If the bucket moves and there is no pressure, this is exactly what should happen but still doesn't explain the high pressure. more head scratching.

Get high pressure on rear remotes and loader stops. Two possibilities, FEL valve is plumbed or machined incorrectly. I.e. Tank line is connected to PB and not to tank.
OR rear remotes are plumbed wrong. I.e. Pressure line goes to rear remotes before going to the FEL.

Sure sounds simple sitting here in front of the key board

Roy

If your loader is only using 5 GPM out of the pumps 9.8, you will have the remainder of the pump flow available to any other valve downstream, so you can have two valves in operation at the same time. .

I have searched everywhere for the pumps max pressure, and have not found it. If no pump on the tractor can produce that pressure, somehow the pressure is being intensified.

I am not sure if he said that the remotes maintained that high pressure or that was the highest he has seen. Is it constant or intermittent?

 

[kuboman]

Will do. What color port did you plug into for the FEL port?

Think is white. I will confirm tonight and re-post.

 

[kuboman]

If your loader is only using 5 GPM out of the pumps 9.8, you will have the remainder of the pump flow available to any other valve downstream, so you can have two valves in operation at the same time. .

I have searched everywhere for the pumps max pressure, and have not found it. If no pump on the tractor can produce that pressure, somehow the pressure is being intensified.

I am not sure if he said that the remotes maintained that high pressure or that was the highest he has seen. Is it constant or intermittent?

It will maintain 32-3300psi. The gear pump on these machines will be capable of 4-5000 psi when new. As for the flow it is a 2 stage pump with the small section supplying the steering and pto clutch. They are separate systems.

 

[kuboman]

Will do. What color port did you plug into for the FEL port?

Yes it is white.Make sure the loader is resting on the ground before you disconnect.

 

[4shorts]

Yes it is white.Make sure the loader is resting on the ground before you disconnect.

Cool. I do it for you in the morning. I'll have pictures too

 

[oldnslo]

Bucket rolls back and the pressure dumps at rear remote. You are right that is what should happen. The more I think about this is I think it has something to do with the flow through to the PB with loader lift circuit. I think with the rear remote activated it dumps a small flow to the backside of the relief which over pressures the remotes. Which also explains:confused2: why lifting the loader and running the remote gives a huge pressure spike.

Kubo,
While raising the loader empty and activating the rear remote you would see increased pressure. This is caused by the differential area on the lift cylinders and the fact that the lift spool ports the return oil to the PB line. I suspect it would be a rare occurrence in real life use where both these functions would be used at the same time.

Any idea what size your lift cylinders are. Would guess around 1.3 ratio which would equate to around 3200 PSI with 2500 PSI inlet.

I believe you stated everything is hard plumbed. Is that correct?

 

[kuboman]

Kubo,
While raising the loader empty and activating the rear remote you would see increased pressure. This is caused by the differential area on the lift cylinders and the fact that the lift spool ports the return oil to the PB line. I suspect it would be a rare occurrence in real life use where both these functions would be used at the same time.

Any idea what size your lift cylinders are. Would guess around 1.3 ratio which would equate to around 3200 PSI with 2500 PSI inlet.

I believe you stated everything is hard plumbed. Is that correct?[/QUOTE

The lift cylinders are 2.17in. Except I get 3200psi with just the rear remote activated. I get the wild spikes when I lift the main lift cylinders.

 

[4shorts]

Test completed. The only test I couldn't do was on the FEL. I found out the female connector on my gauge was to large and I really didn't want to start removing the one on the line due to the mess.

I did however do the test on the rear remote and the gauges I'm using are only a month old and fluid filled so it should be accurate.

Tractor was at normal operating temperature and at idle. I did the test four times with the same results. I also included photo's of the plumbing and routing. Mine tested at 2250 P.S.I. If I can locate the proper fitting to test the FEL portion I'll do that as well. Hope this helps.

 

[kuboman]

Test completed. The only test I couldn't do was on the FEL. I found out the female connector on my gauge was to large and I really didn't want to start removing the one on the line due to the mess.

I did however do the test on the rear remote and the gauges I'm using are only a month old and fluid filled so it should be accurate.

Tractor was at normal operating temperature and at idle. I did the test four times with the same results. I also included photo's of the plumbing and routing. Mine tested at 2250 P.S.I. If I can locate the proper fitting to test the FEL portion I'll do that as well. Hope this helps.

Thats great info. Do you know what your relief is set at? The real test I guess is to know if you have different pressures between the loader and the rear remotes.
Have you done anything to your relief or is it still factory setting?

 

[4shorts]

Thats great info. Do you know what your relief is set at? The real test I guess is to know if you have different pressures between the loader and the rear remotes.
Have you done anything to your relief or is it still factory setting?

It's all still factory. I've never boosted any of the tractors I've owned. The 4240 would pick it's arse up if the bucket was caught under a Hugh lump of snow and ice.

The same holds true for the 5740 although I haven't lifted it's arse up it has lifted some heavy snow with it's double capacity snow bucket so I don't feel the need to boost anything. Works for me