Hydraulic jacks popping

[Derek Perimon]

We have a 2010 Mobile Suite and for a while the hydraulic jacks have been popping.  As of late it has gotten really bad, to the point where i am having to re-level the RV 3 times a month.  i have been told that i can use Automatic Transmission fluid and mix in with the hydraulic fluid and it that will fix the issue.  i also see sites that say use CAT fluid.  will both work?  If so, how much hydraulic fluid do i take out and replace with ATF/CAT fluid?  Thanks 

[GlennWest]

Atf works better in colder weather. I understand you can mix hydraulic oil with atf. 

[Will B.]

From what I understand, you replace it one-for-one.  In theory, the system contains the correct amount.  With your jacks extended, a lot of the fluid is in the hoses.  The instructions are to retract your jacks, take out 1 quart of fluid, replace with one quart of the Fork Oil, or whatever you've decided to use.  Then put the jacks out.  If it doesn't mix really great, another round of in and out should cover it.  I believe you can even add more if it doesn't help over time.  

 

[Dutch_12078]

2 hours ago, GlennWest said:

Atf works better in colder weather. I understand you can mix hydraulic oil with atf. 

Just to be clear, ATF is hydraulic fluid with additives like friction modifiers that automatic transmissions need for the clutches/bands to function correctly. Hydraulic jacks don't need those additives, but they do no harm either. ATF is often used for consumer grade hydraulic applications like RV jacks, motorboat tilt/trim systems, etc, simply because it's readily available.

[GlennWest]

And I was directly answering about his inquiry. Not a general statement.

[Second Chance]

Our Lippert hydraulic system came with ATF in it. There's a Lippert white paper about replacing two quarts of the ATF with either fork oil or CAT fluid to reduce/stop the popping (it's a phenomenon called "stiction"). I tried the fork oil first with minimal effect. I then used the CAT fluid and it cured the problem... though the CAT fluid was hard to find during the pandemic.

Rob

[Danfreda1]

Run you jacks up and down and slides in and out with the CAT stiction fluid to mix and disperse it in all cylinders. Had that problem with our 2011 and that helped it alot

[rickeieio]

I'm guessing that by "CAT fluid", it really means Caterpillar branded hydraulic fluid.  If that's the case, any good hydraulic fluid should suffice.  Don't buy the crap at Tractor Surprise.  Go to a real farm machinery or construction equipment dealer and buy a quart or a gallon.

That said, the motorcycle fork oils do have great anti-stiction additives.  It's pricey, but good.

Not that it matters in this case, but hydraulic fluid is generally 10w.  Fork oil can be had in many viscosities, 5, 7.5, 10, 15, etc.

[Second Chance]

50 minutes ago, rickeieio said:

I'm guessing that by "CAT fluid", it really means Caterpillar branded hydraulic fluid.  If that's the case, any good hydraulic fluid should suffice.  Don't buy the crap at Tractor Surprise.  Go to a real farm machinery or construction equipment dealer and buy a quart or a gallon.

That said, the motorcycle fork oils do have great anti-stiction additives.  It's pricey, but good.

Not that it matters in this case, but hydraulic fluid is generally 10w.  Fork oil can be had in many viscosities, 5, 7.5, 10, 15, etc.

Caterpillar Hydraulic Oil Additive 1U-9891.

Rob

[57becky]

This is the link to the Lippert technical document that deals with the stiction problem:  https://support.lci1.com/documents/ti-191-adding-anti-stiction-fluid-to-hydraulic-systems

[Kirk W]

Is this a common problem today? Is it common to other brands or just Lippert? They don't give that stuff away!

Caterpillar Hydraulic Oil Additive 1U-9891

[TXiceman]

1 hour ago, Kirk W said:

Is this a common problem today? Is it common to other brands or just Lippert? They don't give that stuff away!

Caterpillar Hydraulic Oil Additive 1U-9891

I had this issue on my Big Foot jacks and after talking to them, they recommended Lucas Light weight Fork Oil for motorcycles.  Since Big Foot has a pump and tank at each jack, I removed a pint of oil from each jack and added the Lucas oil.  Then you run the jacks through several full-length travels to get the Lucas oil distributed through the system.   No problem s since.

Ken

[Second Chance]

3 hours ago, Kirk W said:

Is this a common problem today? Is it common to other brands or just Lippert? They don't give that stuff away!

Caterpillar Hydraulic Oil Additive 1U-9891

Lippert has a huge part of the market now, Kirk, and it seems pretty common. Guys on another forum who are engineers and/or have experience with heavy equipment seem to think it's pretty common, too - but with heavy equipment one doesn't notice it since the hydraulics are in motion all the time.

Rob

Edited March 28, 2022 by Second Chance

[Kirk W]

2 hours ago, TXiceman said:

I had this issue on my Big Foot jacks

That is exactly the reason that I asked about it. The downsized travel trailer that we have now doesn't have jacks but we had a class A with Big Foot jacks for 14 years and loved it. It has been a while since we had it but I don't recall having had the problem but do remember that on occasion I would hear popping sound when leveling. If memory serves, my owner's book did say to keep the legs clean and lubricate them and I think that it was silicone spray lubricant that the recommended. When we would park for extended periods of a month or longer, I used to wipe them down with a rag dampened in brake fluid to prevent any rust and then as part of my prep for travel I would clean them well and spray with silicone(or whatever it was that was recommended). Those jacks were on a 1998 RV so were likely an older version of what you have. Do they still recommend the steps as I remember, or something similar?

1 hour ago, Second Chance said:

Lippert has a huge part of the market now

If I'm not mistaken, there seem to be a lot of complaints about their trailer chassis but I don't recall a lot about their leveling systems. Both Big Foot and HWH have a large part of the motorized RV market for leveling and at least some of the trailer market. I wonder if they don't have some of the same issues since they are also hydraulic systems? I have worked on both of those systems but never a Lippert and none of any make in the past 4 or 5 years so have fallen behind on what is happening out there. 

[TXiceman]

Kirk, Our Big Foot jacks did not state popping until they were a couple of years old.  The previous trailer had an older generation of Big Foot jacks and no issues.  There must have been some changes, but the Anti-friction fluid fixed it.

Ken

[Ray,IN]

Don't depend on "he said" comments. Read your owners manual closely, it should state the OEM hyd. oil and approved substitutes.

For instance, my HWH owners manual states HWH oil Or type A ATF.  Later models state Dextron III substitute.