Suspect hydraulic pump (slides) fading

[heyobie]

I have a fifth wheel at an RV park where it now lives. When I arrive I open the slides and when I leave I close them.
When I left last week, the slides moved much slower and I had to push the last slide to get it in.
I fear that I am very close to an ugly problem.

How do you verify that it is the pump? The oil level has been dropping slowly since I have owned this 2016 Keystone Avalanche 38' for 1 year. I filled it about 6 months ago but it continues lose oil.

I can not see any oil leaking. That is a mystery to me. But the leak is slow. If it were a bad leak, the fluid would just get pumped out and nothing would work.

Any suggestions on how to diagnose would be appreciated.

Thank you

[heyobie]

The slides work and hold. No crisis yet. I lose about a quart and a half a year. It is not on the six stabilizers because I can visually see them.

I drilled holes thru the bottom of the RV at the low points to see if oil came out from the 3 main slides. Nothing. The 4th slide in the bedroom is under the bed and can be visually checked. All OK.

So my plan is to cut 3ft squares out of the under belly to examine each of the 3 jacks. I will then devise a way to reinstall so I can easily check or replace a bad jack in the future .

In the fall I added 1 gallon of oil. So I am looking for a gallon of oil an it is not apparent yet where it is hiding. That is the most surprising fact.

I will report back on my progress.

Thank you for telling me that oil is on both sides of the piston. I called Lippert and they did not tell me that.

[jaycocamprs]

heyobie wrote:
Do you think that if a cylinder had an internal leak, it would eventually stop functioning because it will have oil on both sides of the piston?
If true,the system would continue to function and one of the 4 slides would not work properly.
Do you think I'm right?

With a internal leak the oil just goes back to the tank. They are double acting cylinders, oil on both sides. So the non pressure side is always open to the tank. Before you try to open them back up check and see if they are all still tight against the trailer. Ours would not hold the bedroom shut. However you may have more than one bad, since you have loss of oil.

[fj12ryder]

However, that kind of an internal leak would not lead to fluid loss.

I had to replace a hydraulic line when it crazed and actually started leaking fluid through the line. I think I need to replace another one, but it's a long one and I've been putting it off. 🙂

[CA_Traveler]

Thats my understanding but perhaps you can get better information from others.

[heyobie]

Do you think that if a cylinder had an internal leak, it would eventually stop functioning because it will have oil on both sides of the piston?
If true,the system would continue to function and one of the 4 slides would not work properly.
Do you think I'm right?

[CA_Traveler]

2009 The pump was replaced just under the 2 year warranty, sent me the upgraded pump and made it clear no coverage for installation. Helpful in that sense. The Lipper inner plastic hose tends to leak with 2500 psi and then it runs inside the outer plastic hose to the end connector to leak in my case.

With an cyclinder seal internal leak the oil would flow from the pressure side to the non pressure side with no leak evident.

Lipper can supply quality equipment if ordered by mfg but most want high volume lower cost & quality equipment.

[heyobie]

CA Traveler

What year is your RV?

Was lippert helpful?

Do you think the seals on one of my pistons could be leaking internally and my lost oil could be inside?

[CA_Traveler]

My first leak was the pump seal, slides out. Lipper thoughtfully designed the drain area through the motor. Motor unhappy. 😞 And then I found 4 more pump/motor design problems and their redesigned unit is OK. 2 years later 3 of their cheap plastic hoses leaked. Replace all 8 hoses with quality hydraulic hoses.

[heyobie]

The bottom is sealed. I have 4 slides of which 3 I can not see. The slide in the bedroom under the bed is not leaking.
I have 6 leveling jacks which I do not see any oil.

So, the plan is to
1. check the battery voltage at the pump.
2. Assume the leak is the problem and find it.

But the system has worked fine with the disappearing oil and it is not pumping oil out. The pressure seems to be holding just fine.

When I closed the slides (I have a single slide switch), they retracted at a much slower rate than the last 15 times. It seems like it is running at 1/2 power.

While I may have a misterious leak, I am not loosing that much oil to cause my slides to move so slow. If the leak were bad, the oil would be pumped out.

[fj12ryder]

How visible is the underside of the trailer? Oil just doesn't simply disappear. 🙂 If the level is dropping it's going somewhere, my guess would be you have a cylinder leaking in such a position that oil is not getting to the ground and becoming visible. Perhaps a bedroom slide. Time to really start looking in, under, and around.

[CA_Traveler]

The first thing I would check is battery voltage. The most likely areas for a leak is the hose ends, cylinder or hydraulic pump area and should be easy to see or feel.

If you have the type that are all slides in or out vs individual slide control then I would expect an internal cylinder leak is causing the slow slide issue. ie A slide is in but the cylinder leak is returning fluid to the pump. No personal experience with this.