Flush/replace fluid in Lippert slideouts

[daveinaz]

I want to replace the fluid in my slide-outs. The Lippert TI-176 says:

1. Start with clean fluid in reservoir and jacks/rooms in retracted position. [I understand that part!] Remove the bottom (or rear) hose and plug it. Extend jack or room cylinder all the way, catching fluid to avoid mess.

[okay, first question: In the manual it shows the slide-out cylinder with the retract port on the rod end and the extend port on the cap end of the cylinder. I get that the idea is to detach the hose and let the old fluid come out of the cylinder into a catch basin instead of flowing through the hose back to the reservoir. But I am confused as to which way the fluid is flowing here. Is the fluid pushing into the cylinder from the extend port when you extend the slides? If that's the case, then I would need to detach the hose from the retract side? Or when extending the slides, would I detach the hose from the extend port and catch the fluid coming out of that end?]


2. Now, with jack/room extended, push fresh fluid through hose until you know it is clean. Connect to cylinder. Remove the top or front hose and plug it. Fully retract cylinder catching fluid. When fully retracted, push fresh fluid through hose until clean. Connect to cylinder and cycle to eliminate any residual air.


[Step two is the opposite of step 1. If I get step one done, I know to just do the opposite for step 2]

3. Use this process for each jack/room cylinder, one at a time, and this will get the majority of the old fluidvout of the system. No process will be 100% but this should get you to 95+.


Thanks!!

[DQDick]

Curious as to why you want to do this?

[richfaa]

Originally Posted by DQDick

Curious as to why you want to do this?

Me also.

[1retired06]

Originally Posted by DQDick

Curious as to why you want to do this?

Same here. Maybe some sort of contamination?

[daveinaz]

Why? Well, the fluid in the reservoir didn't look like ATF... tan instead of red. And the unit is 10 years old. If ya'll think it's not necessary, let me know and I'll just flush / refill the reservoir with new fluid and not worry about what's in the lines and cylinders.

I just thought it'd be a good idea, but I'm new to this so maybe it isn't.

[Carl n Susan]

Montana fills the reservoir with clear fluid at the plant. As you add ATF, the color changes. After 10 years I would expect it is no longer clear.

[rohrmann]

I’m not sure which Lippert manual I read this, but they suggested siphoning the fluid out of the reservoir when all the slides are in and jacks retracted, and fill the reservoir with new fluid, and I think it was at three years. I did that and the fluid I removed was pretty dirty. When I did this, I put a couple quarts of the CAT stiction fluid in and filled it the rest of the way with ATF. Just a little PM.

[rohrmann]

I found the old manual on line and it has been superseded by a newer version that does not have the recommendation to drain and refill the reservoir any more. This is the link to the old manual, and on page 27 is where it described the drain and fill maintenance. https://www.lci1.com/assets/content/...s_Manual_S.pdf

[DadsHemi]

My 17 came with atf fluid, why would you not want to change it....it will collect mosture as any hydraulic fluid or oils.

[mazboy]

I'm in the group of why?


If it isn't broken don't change it.

[richfaa]

Although we have never changed ours over 12 years in two Montana's it is no big deal to change and flush if you choose to.

[daveinaz]

so, it sounds like the majority says not to worry about the old fluid in the lines or cylinders.

However, I'd still like to know about the fluid flow in the retract and extend ends of the cylinder if anyone happens to know about that.

Thanks.

[daveinaz]

I just finished talking to Lippert. He said that the tank came filled with AW32 hydraulic fluid not ATF which is why the fluid in the tank was honey colored instead of reddish. He said that you aren't supposed to mix AW32 and ATF and that I should indeed flush the system if putting ATF in the tank. I asked him if that was the case, then why did the manual say to fill the reservoir with ATF? He said that most OEMs do fill the reservoir with ATF. So anyway, I guess Keystone put AW32 in the reservoir? And since I already put ATF in the tank, I need to flush the system. And in case anyone is interested, this is how I need to do it per Lippert:

1. Retract all the slide-outs and fill the reservoir with ATF.
2. Close all but one of the slide-outs on the IRC block.
3. Go to the first slide-out you're going to flush (I'm starting with the main slide-out) and remove and plug the hydraulic line from the rod end of the hydraulic cylinder.
4. Place a hose of the fitting where the hose was attached and run the hose to a catch basin/bucket.
5. Extend the slide and collect the fluid from the cylinder as it extends. Fluid will come out until the slide is almost fully extended.
6. Fill detached hose with fresh fluid and reattach.
7. Remove and plug hose from cap end of cylinder.
8. Attach hose to fitting and run hose to basin/bucket.
9. Retract slide and collect fluid into basin/bucket as it retracts.
10. Fill detached hose with fresh fluid and reattach.
11. Cycle slide-out a few times to purge air from system.

12. Repeat steps 3 - 11 for the remaining slide-outs, opening and closing the corresponding valves on the IRC accordingly.

I have attached the chat transcript from Lippert.

[skypilot]

All of my slide-out cylinder's are covered by the plastic sheeting underneath. Seems like a royal pain. Wonder if it wouldn't be just as good to drain the reservoir, fill it with ATF, then cycle all of the hydraulics a few time, drain again, fill again, and cycle a few times. Do this several times and I'd think you'd get a blend that is mostly ATF. I'm definitely no expert but seems logical to me.

[ChuckS]

I too spoke with Lippert regarding changing out my hyd reservoir fluid due to age... it’s five years old.. Lippert recommend replacing it around that time frame..

Not ALL hyd reservoirs are filed with the same fluid..

Some are filled with AW32
Some are filled with ATF

Lipperts service bulletin TI-188 is miss leading as it states use ATF and has several recommendations to type of ATF..

If your fluid is honey color or dark brown it’s AW32

If it’s red it’s ATF

Lippert recommend to me to close slides and gear..siphon out the fluid..
Fill with AW32 and not use ATF with my system

Cycle slides and gear a few times
Siphon out reservoir again with slides and gear in
Service up reservoir with AW32

This procedure will get most all old fluid out without dropping colorplast and breaking hyd fitting line connections and making a mess plus potential for leak down the road

Gallon of AW32 is about $12

[wecker1]

I too spoke with Lippert and was informed that if your fluid is red, refill with Dexron III / Mercon V transmission fluid, if your fluid is clear or amber, refill with AW32 hydraulic oil.

With everything retracted, fill to .25" of the top of the reservoir.

[daveinaz]

Well, I had to pull the chloroplast anyway to replace the burst hydraulic line. Then I did as per their instructions and bled the fluid from the cylinders -- well, all except for the bedroom side because I couldn't find my square driver to get the screws out to remove the bed platform to get to it.

I still need to go back and reattach the chloroplast better. At the factory they missed the frame crossmember when attaching the overlapping pieces and just screwed the two pieces into each other. I think I'll get my big t-square out and mark the crossmember location on the chloroplast and make sure to screw it properly into the metal this time.

I also found a rusty spot on the frame underneath the city water connection when I took all that stuff off so I want to do some rust treatment and paint there before it gets any worse.

Of course, after crawling around under the rig for 5 or 6 hours I was stiff for two days.

[daveinaz]

Originally Posted by wecker1

I too spoke with Lippert and was informed that if your fluid is red, refill with Dexron III / Mercon V transmission fluid, if your fluid is clear or amber, refill with AW32 hydraulic oil.

With everything retracted, fill to .25" of the top of the reservoir.

I wish I'd read that sooner. If I had flushed/filled the reservoir with AW32 instead of ATF I would not have had to go through all of this! That's what I get for reading and going by the manual!

[saber707]

Been RVing for 20 years or more. Never have known anyone that has done that.

[daveinaz]

Originally Posted by saber707

Been RVing for 20 years or more. Never have known anyone that has done that.

Never done what? Flushed their hydraulic fluid? Or unknowingly added ATF to their AW32?

I get that there may be no need to flush ATF or AW32 but I have not heard from anyone regarding what to do if the two are mixed. It seems that once I added ATF to the AW32 in the reservoir (not knowing it was AW32 and not ATF or I would never have filled it with ATF) I needed to flush it so that there was only one type of fluid in the system.