Hydraulic stabilizers settling

[Ranchhand]

So the wife and I made the 650 mile round trip today to get are new to us 2021 avalanche 378BH. Picked iy up this morning and after travelling about 75 miles we pulled over to get something to eat and do a quick walk around to just check things out. Upon the walk around i see that the back right stabilizer jack is abou two inches off the pavement. I retracted the jack and decided to put a small ratchet strap on it to make sure it did not come out again. Drove about another hundred miles and decided to check on it again to make sure my strap was holding ok. At this point now the right jack in front of the wheels had settled down. I did not put a strap on the front one. I decided to risk it and just stop a couple more times before we got home. Each time I stopped the same jack in. front of the tires had setteled. No other jacks at this point seem to have setteled at all. There are no visiable leaks. I assume it is tranfering oil internally. Anyone have situations like this that has happened to them Or any suggestions where to start looking. The dealer i bought it from is willing to work with me on it but did not have any great suggestions on what to try.

[ChuckS]

The mid and rear leveling jacks on each side are connected in tandem.. if either one has an internal leak ( yours does ) then both the mid and rear leveler legs will be affected ..

You troubleshoot and find out which leveling leg is leaking internally there is a simple test you can easily do if yo7 have some basic mechanic skills.

https://lci-support-doc.s3.amazonaws...cd_0001910.pdf

https://youtu.be/hXYp3w3S-ok

[Ranchhand]

Originally Posted by ChuckS

The mid and rear leveling jacks on each side are connected in tandem.. if either one has an internal leak ( yours does ) then both the mid and rear leveler legs will be affected ..

You troubleshoot and find out which leveling leg is leaking internally there is a simple test you can easily do if yo7 have some basic mechanic skills.

https://lci-support-doc.s3.amazonaws...cd_0001910.pdf

https://youtu.be/hXYp3w3S-ok

So just to clarify if just the right rear jacks are settling then the problem is on one of the right jacks or the power unit or the valve as the video states. the right jacks are a pair in tandem by themselves and the left pair are in a tandem by themselves. So the problem would strictly be just on the right side

[ChuckS]

Originally Posted by Ranchhand

So just to clarify if just the right rear jacks are settling then the problem is on one of the right jacks or the power unit or the valve as the video states. the right jacks are a pair in tandem by themselves and the left pair are in a tandem by themselves. So the problem would strictly be just on the right side

The “usual” cause of one of the issue you are seeing … mid/rear leveler jacks creeping down (on the same side) is an internal leaking cylinder on either the mid or the rear leveler on the side affected.. that’s why you have to test both ..

There are other items in the system that can also cause your issue..
1. There is a Hydac valve for each mid/rear leveler combo., if the manual override screw on the Hydac cartridge for the right side is not fully closed mechanically it will allow fluid to flow past ..thus the creeping leveler legs ( on one side only )
2. An external fluid leak on either of the lines to either of the mid/rear leveler legs ( on one side. )

You can easily verify the Hydac valve for the right mid/read leveler leg is fully closed by locating it and using a 5/32 Allen wrench in the end of the valve. The screw should be just snug tight on the end of the cartridge valve

Note.. the front LG Hydac valve is mounted directly on one of the front LG..usually the passenger side,

The remaining Hydac valves..in your case there will be (3) are mo7nted on the extend side manifold located near the hydraulic pump

To tell which Hydac valve is what look at the wires going to those valves.

Each valve will have one wire the same color (ground)

The remaining wires are shown in pic.. two are for left and right (mid/rear) levelers and the last wire ((not highlighted in chart) is for your hydraulic slides

[ChuckS]

One last image to help you locate your extend manifold and Hydac valves..image from my Alpine.. my extend manifold is mounted inside the pump area as shown..

The yellow arrows indicate where the manual over ride screws are located.. yours will be similar..

I added this just to help you locate the Hydac valves.believe your issue is gonna be on one of those right side leveler legs bypassing internally

[Ranchhand]

Originally Posted by ChuckS

One last image to help you locate your extend manifold and Hydac valves..image from my Alpine.. my extend manifold is mounted inside the pump area as shown..

The yellow arrows indicate where the manual over ride screws are located.. yours will be similar..

I added this just to help you locate the Hydac valves.believe your issue is gonna be on one of those right side leveler legs bypassing internally

Ok thanks for all the help. I will see what I can determine tomorrow. Thank you