L**40 rear hydaulic pressure

[J_J]

We would all like to see a picture of the 3200 psi on your gage.

One other thought came to mind. Did you perhaps drop the gage and cause it to read high.

If you put it back on the FEL valve for a pressure check would it read 2550 psi as you stated? If so, then we can eliminate that possibility.

 

[kuboman]

We would all like to see a picture of the 3200 psi on your gage.

I will see if I can get that done today.:thumbsup:

 

[oldnslo]

I will see if I can get that done today.:thumbsup:

Kubo,
If you try this can you feather the rear DCV valve to build the pressure slowly. IF the pressure holds steady at 2500 - 2600 try shifting the valve faster. Just curious to see if the possibility exists that the first time you may have trapped a pressure spike by shifting the valve to fast. If the rear DCV valve is like the front it has the anti-drift or load drop check in the pressure line. This check would capture any pressure spike and could explain the high reading.

Just trying to eliminate another variable.

best of luck

Roy

 

[kuboman]

Kubo,
If you try this can you feather the rear DCV valve to build the pressure slowly. IF the pressure holds steady at 2500 - 2600 try shifting the valve faster. Just curious to see if the possibility exists that the first time you may have trapped a pressure spike by shifting the valve to fast. If the rear DCV valve is like the front it has the anti-drift or load drop check in the pressure line. This check would capture any pressure spike and could explain the high reading.

Just trying to eliminate another variable.

best of luck

Roy

Good thought but I tried the feathering. Just a nice steady build to 3200 psi

 

[kuboman]

Ok here some pics.

Some of the gauge on the rear remote and some of on the loader. A few of the installation.
All taken same rpm and temp.

 

[oldnslo]

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

 

[kuboman]

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

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.

 

[4shorts]

Rather than me reading through all the posts did anyone measure there pressure yet on there Grand L for you to make a comparison ? I got my gauges back this evening so if you want me to measure mine I can tomorrow. Just tell me where you want the gauge plugged into, the engine RPM and engine temp.

 

[kuboman]

Rather than me reading through all the posts did anyone measure there pressure yet on there Grand L for you to make a comparison ? I got my gauges back this evening so if you want me to measure mine I can tomorrow. Just tell me where you want the gauge plugged into, the engine RPM and engine temp.

Have not had a response with anyone else with one so if you can check yours then we all can be a little wiser. I went to the dealer today to try one there and they were closed so that was a waste of time.
If you would try the pressure at your rear remote and also on one of your loader ports. I use the down circuit on the lift arms for my tests. That way the loader is on the ground and nothing can get out of hand.
Engine at idle oil room temp. Just bypass for a few seconds to let things stabilize and that should tell us what we need.
I appreciate you time and effort on this.:thumbsup:

 

[4shorts]

Have not had a response with anyone else with one so if you can check yours then we all can be a little wiser. I went to the dealer today to try one there and they were closed so that was a waste of time.
If you would try the pressure at your rear remote and also on one of your loader ports. I use the down circuit on the lift arms for my tests. That way the loader is on the ground and nothing can get out of hand.
Engine at idle oil room temp. Just bypass for a few seconds to let things stabilize and that should tell us what we need.
I appreciate you time and effort on this.:thumbsup:

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