Landing gear lowers over time

[maclaff]

I own a 2015 Heartland Big Country 3650 RL. It has been in the same location for multiple months. It appears that the landing gear goes down an inch or more in a week or so, making the rig not level, which complicates the W/D staying level. I believe it is a Lippert system. What are possible causes?

 

[Dahillbilly]

external leak could be from hoses,fittings or cylinder seals which you wouls see a fluid leak. Internal leakage is hard to find as it could be internal cylinder leaking or a control valve letting fluid seep back into the pump or tank. Hard to pinpoint a internal leak. Good luck

 

[travelin2]

Unless you can see any visible fluid loss, it’s likely an internal seal in the leveler. They can be serviced. I’ve had 3 rebuilt in the past year. 2 for external visible leaks and the other for the internal seals.

Call lippert. There’s a test that can be done to determine which front jack, but off hand I’d bet it’s the off door one

Block up the frame, remove the jack, and take it to a hydraulic shop for repair. Likely take a couple of weeks unless you can really plead your case

Good luck

 

[centerline]

if the system is equipped with a holding valve, it probably has a small piece of debris keeping it from closing all the way.... it only takes a piece about a quarter the size of a small grain of sand...

 

[cgaskins]

Uhggg... I have same problem.

So I have a 2015 Heartland Big Country 3450RL. So my issue where I need a little advice is that two of my 6 hydraulic leveling jacks leak down while in storage. So I parked my RV from my last trip in early May with the back four jack retraced and only the front landing gear extended. I went over to my storage facility yesterday to check on it and the two middle leveling jacks (just forward of the axles) had leaked down. One side had extended about 5 inches and the other side about 2 inches. The jacks in the rear (behind the axles) had not extended. I did a quick inspection (not a detailed on just a quick glance as it was getting dark) and I didn't see any hydraulic fluid leaks.

So over the past 7.5 years, that we have had this trailer, I have had to replace every single jack due to fluid leaks and failures. Last January (2022), I had all of the hydraulic lines replaced as they were leaking around the couplers.

Sure wish there was a better way to figure out what is going on....

 

[cookie]

You might find some good trouble shooting tips here.

Peace
Dave

 

[travelin2]

Uhggg... I have same problem.

So I have a 2015 Heartland Big Country 3450RL. So my issue where I need a little advice is that two of my 6 hydraulic leveling jacks leak down while in storage. So I parked my RV from my last trip in early May with the back four jack retraced and only the front landing gear extended. I went over to my storage facility yesterday to check on it and the two middle leveling jacks (just forward of the axles) had leaked down. One side had extended about 5 inches and the other side about 2 inches. The jacks in the rear (behind the axles) had not extended. I did a quick inspection (not a detailed on just a quick glance as it was getting dark) and I didn't see any hydraulic fluid leaks.

So over the past 7.5 years, that we have had this trailer, I have had to replace every single jack due to fluid leaks and failures. Last January (2022), I had all of the hydraulic lines replaced as they were leaking around the couplers.

Sure wish there was a better way to figure out what is going on....

Cycle the landing gear. Probably a speck of dirt in the hydac valve for those 2 jacks

BTW-have you ever changed the fluid? Changed mine recently. Look at all the dirt that settled out of less than 2 quarts

 

[centerline]

Uhggg... I have same problem.

So I have a 2015 Heartland Big Country 3450RL. So my issue where I need a little advice is that two of my 6 hydraulic leveling jacks leak down while in storage. So I parked my RV from my last trip in early May with the back four jack retraced and only the front landing gear extended. I went over to my storage facility yesterday to check on it and the two middle leveling jacks (just forward of the axles) had leaked down. One side had extended about 5 inches and the other side about 2 inches. The jacks in the rear (behind the axles) had not extended. I did a quick inspection (not a detailed on just a quick glance as it was getting dark) and I didn't see any hydraulic fluid leaks.

So over the past 7.5 years, that we have had this trailer, I have had to replace every single jack due to fluid leaks and failures. Last January (2022), I had all of the hydraulic lines replaced as they were leaking around the couplers.

Sure wish there was a better way to figure out what is going on....

for anyone who has a rig with hydraulic issues.....

if there are continual problems with the hydraulic system, the relief valve setting should be checked, as too much pressure can cause repeated/continual and unnecessary leaks and hose failures..... the relief valve only needs to be set high enough to pull the slides in dependably everytime.... "common" hydraulic systems typically run between 2800 and 3200psi.... and it should only take about 1800psi to operate the slide units...
non "common" systems can run in the low triple digit pressures for a low pressure pilot system, or up to around 5500psi, and higher depending on the application....

without looking up the specs, I would bet the relief valve setting should be between 2200-2600psi for the hydraulic system.... but it may also be a pre-set, non adjustable relief valve, in which case replacing the valve would be the only option if the pressures are found to be incorrect....

check valves, pressure relief valves and holding valves DO fail sometimes, and they are the only 3 pieces that allow a hydraulic system to work dependably without destroying itself.... they are the only "fail safe" devices within the system, and any little piece of debris, overheating, or failed/broken spring can cause either too much or not enough pressure to operate the system as designed.....

for ANY one who reads this, hydraulic oil expands and contracts with temperature change... which means, when you FULLY retract or extend the slideout, as the atmospheric temperatures heats up and cools down there can be extreme pressure changes....

the pressure that is built up and locked INSIDE the fully retracted (or fully extended) side of the cylinder is going to increase a substantial amount more, UNLESS a "properly" working pressure relief valve is in the system which will allow this damaging over-pressure to escape thru the valve, relieving the high pressure oil back to the reservoir, where it its harmless... rather than allowing it to find/force its way out of the system....

a cylinder like a jack cylinder that when in use and that is not fully extended/retracted can move slightly either way as the day heats up or cools down and expands/contracts the oil, but slide units that are usually fully in or fully extended, AND hydraulic jacks that get fully retracted for travel are susceptible to premature failure... and if the pressures within the system are not correct, just replacing the seals will NOT make it better, but may stop the leaks for a month or two.......

a faulty relief valve can be the cause of failed cylinder seals, because they arent able to withstand the high internal pressures, so the plastic and rubber seals get deformed and pushed out of the way to allow the fluid to bypass to the other side of the cylinder..... sometimes when this happens, a small piece of debris may try to pass and get caught in the seal, holding it open as the pressure is reduced, but allowing it to leak fluid... the only way to prevent this is to keep clean oil and when you come to the end of a cylinder, STOP and dont continue holding the button and building pressure.... UNLESS you have checked the system pressures to make sure its correct or the problem will NEVER go away....

you CAN hold the button on a system with a working PR valve, without worry of blowing seals, or allowing the temperature to have any effect on the pressure.... a properly working system should allow many years of trouble free service, without leaks or seepage....

 

[cgaskins]

Cycle the landing gear. Probably a speck of dirt in the hydac valve for those 2 jacks

BTW-have you ever changed the fluid? Changed mine recently. Look at all the dirt that settled out of less than 2 quarts

You, how that is a really good point. Never changed it. I assume you just pulled all the jacks and slides in so the reservoir is full, then sucked it out all out with with a fluid pump. That is an easy task that I should do first. What type of fluid is the best to replace it with?

Thanks!

 

[cgaskins]

for anyone who has a rig with hydraulic issues.....

if there are continual problems with the hydraulic system, the relief valve setting should be checked, as too much pressure can cause repeated/continual and unnecessary leaks and hose failures..... the relief valve only needs to be set high enough to pull the slides in dependably everytime.... "common" hydraulic systems typically run between 2800 and 3200psi.... and it should only take about 1800psi to operate the slide units...
non "common" systems can run in the triple digit pressures for a low pressure pilot system, or up to around 5500psi....

without looking up the specs, I would bet the relief valve setting should be between 2200-2600psi for the hydraulic system.... but it may also be a pre-set, non adjustable relief valve, in which case replacing the valve would be the only option if the pressures are found to be incorrect....

the lippert service manual has NO information about any of the mechanicals within the hydraulic system, so pressure setting would be information that has to come from the manufacture of the hydraulic unit.... or just replace the valve without checking it, but a properly operating hydraulic system should be a lifetime installation without leaks UNTIL a seal gets old and fails...... the system should NOT fail on a regular basis...unless the pressures are too high, which is indicated by the fact that you claim the NEW hose's start leaking near the fittings after a time...

check valves, pressure relief valves and holding valves DO fail sometimes, and they are the only 3 pieces that allow a hydraulic system to work dependably without destroying itself.... they are the only "fail safe" devices within the system, and any little piece of debris, overheating, or failed/broken spring can cause either too much or not enough pressure to operate the system as designed.....

for ANY one who reads this, hydraulic oil expands and contracts with temperature change... which means, if youFULLY retract the slideout/jacks in the morning, when the day heats up or there are other pressure changes due to going over a mountain pass. the pressure that is built up INSIDE the retract side of the cylinder is going to increase a substantial amount more, UNLESS a "properly" working pressure relief valve is in the system.... this can be the cause of failed cylinder seals that cant withstand the internal pressures, and so the plastic and rubber seals get deformed and pushed out of the way to allow the fluid to bypass to the other side of the cylinder..... check the system pressures and make sure its correct or the problem will NEVER go away....

This is really good information, I need to re-read it and make sure I am consuming it properly. I am pretty good with mechanical items but I am not very experienced with hydraulics....

Thank you!

 

[travelin2]

You, how that is a really good point. Never changed it. I assume you just pulled all the jacks and slides in so the reservoir is full, then sucked it out all out with with a fluid pump. That is an easy task that I should do first. What type of fluid is the best to replace it with?

Thanks!

I’ve replaced ours twice. The first time was at the direction of Lippert support
The second time after a front landing jack was rebuilt for damaged internal seals
Both times I replaced it with private label synthetic ATF from Autozone

 

[wdk450]

When visiting the hydraulic cylinder/line experts, I would ask about an add-on hydraulic fluid filter (like is in every automatic transmission).

 

[cgaskins]

So I continue to struggle with my leaking jacks on my Big Country. A few weeks ago, I emailed the team at Lippert the following information:

I have a 2015 Heartland Big Country 3650RL 5th wheel. It is equipped with the Lippert 6 point hydraulic leveling system. Over the years I have had to replace all 6 jacks (mostly in the last 2 years) due to leaking seals in the jacks evidenced by hydraulic fluid running down the jack. Back in January of 2022, I had all of the hydraulic hoses changed (to the sides and to the jacks) as they were starting to leak. At this point, I thought all of problems were solved and I was good to go.

However, recently on a trip in May noticed that the leveling jack on the passenger side in front of the axle had dropped down about 4 inches. This was on a long 8 hour travel day. I then inspected all the jacks and noticed that the one in front of the axle on the driver’s side had dropped about an inch. I retraced them and put my RV in storage.

A couple of weeks ago, I was checking on my RV and noticed that the same two jacks had dropped again. So this had been over the time period of probably 5 or 6 weeks. I retracted the jacks and this time used small tie-down straps on both of the problematic jacks (in front of the axle). I came back about 2 weeks later and now the jack behind in the axle on the passenger side has dropped about 2 inches.

I am not sure how to trouble shoot this…. I am not low on hydraulic fluid. All the jacks work. I can fully auto-level the system with no issues. I have checked the connections where the hydraulic lines come into each jacks mechanisms and the slide mechanisms and I see NO leaks. I checked the manifold near the hydraulic pump, no leaks. What am I missing?

The response I got from Lippert is below:

Thanks for reaching out.

I would suggest checking the valves to make sure they are closed properly. If the valves are closed, I would suggest having a bypass test completed on the jacks themselves, to see if there is an internal leak.

Let us know if you have any questions.

My question is how do I check that the valves are closing properly?

Thanks.

 

[travelin2]

So I continue to struggle with my leaking jacks on my Big Country. A few weeks ago, I emailed the team at Lippert the following information:



The response I got from Lippert is below:


My question is how do I check that the valves are closing properly?

Thanks.

I suspect lippert is referring to the Hydac valves. There is one one the front off door side jack. The others in our Bighorn are in the front compartment near the hydraulic pump

I believe it’s a 5/16” allen wrench that’s needed. On the end of the valve is an adjustment. Left hand threads. Turn right to loosen, left to tighten.

Lippert should have directions on YouTube. But I’d loosen the valve body a turn or so, cycle the front jacks, tighten but DO NOT over tighten! See what happens

I’m still going to say it’s a leaking bypassing seal in the off door side jack. I replaced Hydac valves during my troubleshooting and it boiled down to a leaking seal in the jack. Had the jack rebuilt in April. All good since

 

[cgaskins]

Thank you for the info. I can tie up various jacks on my trailer with tie-down straps and the problem moves around. If it was a specific jack, I don't think that would be happening. So just to get my terminology straight... I assume the Hydac valve is mounted in the hydraulic manifold. Correct?

 

[travelin2]

Thank you for the info. I can tie up various jacks on my trailer with tie-down straps and the problem moves around. If it was a specific jack, I don't think that would be happening. So just to get my terminology straight... I assume the Hydac valve is mounted in the hydraulic manifold. Correct?

There are multiple Hydac valves.

There is one on the front off door side leading jack. This one is for the front jacks. I had strap up both front jacks so that neither one could drift down on travel days

The other Hydac valves for the other landing jacks and hydraulic slide outs are in the front generator compartment on a manifold next to the level up pump

As I mentioned in my previous comment, I replaced all of them to no avail.

It wasn’t until I had the off door side jack rebuilt that the drifting issue was corrected

 

[travelin2]

Hydac valve on leading jack

 

[cgaskins]

Thank you sir.

 

[travelin2]

Thank you sir.

Good luck!!