Hydraulic Fluid Level

[On-the-Road-Again]

Hi. Maiden voyage in my 2016 cedar creek Hathaway 36 I was checking the fluid levels and noticed that the hydraulic fluid level was 1 inch from bottom. I have my jacks down with slides out. Question: is this normal or do I need to add fluid. Should I assume to add auto transmission fluid?

[CHICKDOE]

if it is the lippert system check the oil level when the legs are up and the slides in. if you add it now it may overflow once everything is retracted. yes is uses automatic transmission fluid but it wants a specific type. i believe it is the type that has mercon in it but do not take this as gospel. the owners manual describes how to check fluid level and what type of fluid to use.

[SilhouettePenny]

Maxima Fork Oil grade 15, for your CC hydraulic system, I get it from Amazon. Also recommended is Torco RFF Grade 15 and Caterpillar Hydraulic Oil Additive #1U-9891, whatever you can source locally.

[brownm1]

Lippert has an app that is very useful for all your questions.

[5picker]

You can never check fluid levels or top off the reservoir if/when any hydraulic slide(s) or leveler(s) is extended. When extended, the oil in the reservoir is now in those extended rams and once retracted, will flow back into the reservoir.

Only check the level with everything retracted.

[kenandterry]

What 5picker says ^^^^^^^^^

[dieselguy]

I do agree that all slides and leveling rams need to be retracted when reservoir fluid is checked. To clarify a couple of replies … our hydraulic systems have auto tranny fluid in them to start with. If you have popping noises from the auto level rams while set-up on your campsite ... Lippert recommends removing up to a couple of quarts of oil from your reservoir and replacing that with the Maxima, Torco, or Caterpillar fluid. https://www.lci1.com/images/support/lipsheet/0295.pdf
As for where the oil is … in actuality there is always fluid on one or the other side of the cylinder piston on a double acting hydraulic cylinder. The extension side of the cylinder takes more fluid because the retraction side of the cylinder contains the cylinder ram which displaces fluid.

[LittleBill]

Not our maiden voyage, but about the third in our brand new 36CK2 which is the first unit I have had with a hydraulic system for the slides as well as an automatic leveling system. We were all packed up and had everything stowed, when we ready to run the slides in at the end of a lovely week camping. The bedroom slide came in OK, but when the refrig slide started in it only came about half way when it stopped. After trying to assist that slide by pushing it and running the hydraulics it came in almost all the way, but the dinette slide wouldn't budge at all. As we were suppose to be out of the site by a certain time, I began to frantically to look over the system and found that that the hydraulic fluid in the reservoir appeared low below the inlet for the pump. So hastily went to the nearest hardware store and bought 3 quarts of dexron transmission fluid. Upon getting back added a quart and being it stilled looked low added a second and a little of the third one. The slides came in the rest of the way with no problem and was able to raise the unit to hitch height and hook up the TV. After raising the front jacks is when I really felt like a fool when I started seeing hydraulic fluid coming out the front corner of the unit onto the ground. You guessed it, over filled the reservoir. Wish Lippett had a mark at the bottom for when slides and jacks are extended. Needless to say I will definitely be aware of this if I have to ever add fluid again. I now carry a spare quart of fluid in case it runs low again as we were lucky finding a place open that had hydraulic fluid on a Sunday. Also I bought a hand pump (squeeze bulb type) to add or remove fluid to the tank as there is barely any room between the top of the reservoir and the ceiling above it. Can now at least laugh about it.

[NMWildcat]

Originally Posted by LittleBill

Not our maiden voyage, but about the third in our brand new 36CK2 which is the first unit I have had with a hydraulic system for the slides as well as an automatic leveling system. We were all packed up and had everything stowed, when we ready to run the slides in at the end of a lovely week camping. The bedroom slide came in OK, but when the refrig slide started in it only came about half way when it stopped. After trying to assist that slide by pushing it and running the hydraulics it came in almost all the way, but the dinette slide wouldn't budge at all. As we were suppose to be out of the site by a certain time, I began to frantically to look over the system and found that that the hydraulic fluid in the reservoir appeared low below the inlet for the pump. So hastily went to the nearest hardware store and bought 3 quarts of dexron transmission fluid. Upon getting back added a quart and being it stilled looked low added a second and a little of the third one. The slides came in the rest of the way with no problem and was able to raise the unit to hitch height and hook up the TV. After raising the front jacks is when I really felt like a fool when I started seeing hydraulic fluid coming out the front corner of the unit onto the ground. You guessed it, over filled the reservoir. Wish Lippett had a mark at the bottom for when slides and jacks are extended. Needless to say I will definitely be aware of this if I have to ever add fluid again. I now carry a spare quart of fluid in case it runs low again as we were lucky finding a place open that had hydraulic fluid on a Sunday. Also I bought a hand pump (squeeze bulb type) to add or remove fluid to the tank as there is barely any room between the top of the reservoir and the ceiling above it. Can now at least laugh about it.

If you have to add fluid because your fluid is too low to work the system, you have leak.

[LittleBill]

NMWildcat, thanks for pointing out about a possible leak. Did look, but haven't found anyplace where it may have leaked. Since having the low fluid issue, haven't seen any fluid on my asphalt drive where we have had the unit several times (running the slides in and out almost daily while sitting there as don't like them extended overnight with no one in it). Nor on the ground where we store it. Also have had it into the shop for warranty stuff and informed them about the fluid. They didn't find anything either
Grabbing at straws, I attributed the low fluid to being being close to low upon delivery to start with and then possibly air in the lines being replaced by fluid as the unit was still new and this was only our 3rd time out with it. Temperature may have had an effect on it as this was when we were in Door County, WI in Oct. Don't know for sure why any of this happened and may never know. ON-THE-ROAD-AGAIN appears to have the same issue I had with their new unit that is also may be a 36CK2 like mine.
I continually check the level now when I get ready to pull it out and haven't seen it deplete. It still would have be nice to have had a minimum/maximum mark on the reservoir for when everything is extended as that is when you tend to check things out on the unit. I have put a tentative mark on it myself. By the way I should have considered when adding fluid that when all is retracted fluid will return to the reservoir. Too much in a hurry to leave site and frustrated over it being low to begin with. My bad .
__________________

[NMWildcat]

Originally Posted by LittleBill

NMWildcat, thanks for pointing out about a possible leak. Did look, but haven't found anyplace where it may have leaked. Since having the low fluid issue, haven't seen any fluid on my asphalt drive where we have had the unit several times (running the slides in and out almost daily while sitting there as don't like them extended overnight with no one in it). Nor on the ground where we store it. Also have had it into the shop for warranty stuff and informed them about the fluid. They didn't find anything either
Grabbing at straws, I attributed the low fluid to being being close to low upon delivery to start with and then possibly air in the lines being replaced by fluid as the unit was still new and this was only our 3rd time out with it. Temperature may have had an effect on it as this was when we were in Door County, WI in Oct. Don't know for sure why any of this happened and may never know. ON-THE-ROAD-AGAIN appears to have the same issue I had with their new unit that is also may be a 36CK2 like mine.
I continually check the level now when I get ready to pull it out and haven't seen it deplete. It still would have be nice to have had a minimum/maximum mark on the reservoir for when everything is extended as that is when you tend to check things out on the unit. I have put a tentative mark on it myself. By the way I should have considered when adding fluid that when all is retracted fluid will return to the reservoir. Too much in a hurry to leave site and frustrated over it being low to begin with. My bad .
__________________

Sounds like you have all your bases covered and it makes sense, especially since you haven't had any more problems. Fingers crossed!
I complained about the lack of a fill mark also when we got our unit. Was told they put these units in lots of very different rigs, so no one fill line would work. Also when would folks check it? All hydraulics withdrawn, all extended, only landing gear down? So, I did the same as you, with only landing gear gear down, I put a labeled mark. Also another labeled mark with all levelers down and slides out.
Have only had to add oil once in 7 years when changing out one leveler. Was very easy job as these systems are self bleeding.
Hope you have continued success with yours! Happy RVing.

[LittleBill]

Me too! I do now carry a small inexpensive hand pump that I carry in my tool box for those times just in case I need to add fluid or remove excess fluid (hopefully never overfill again). Without the pump it was quite messy adding fluid due to the confined space around the fill port.

[BandJCarm]

I spent the first two years of my 36CKTS with leaks. However, I didn't know I had leaks. What I did know, is that my slides would creep out while driving down the road. In fact, once they all retracted all the way, they would instantly begin creeping out.


Finally found someone to work on it that knew what they were doing (Lippert sent a field tech to work on it, and he screwed it up worse than ever, made a total mess, cut wires, did all kinds of insanity), they THOUGHT they fixed it by finding a leak in TWO rams. NOTE: Even though two rams were leaking, there was no significant loss of reservoir fluid, at least not visible.


In a few months, the problem returned. Still, no visible drop in reservoir fluid. Same guy worked on it and this time replaced all three rams (I have 3 slides) and Voila@!!! Problem fixed. It has stayed fixed.


3 bad rams...........from the manufacture. Crazy. But leaks can occur inside the pump, in the rams, etc. If it's just enough to not hold pressure, then you have a problem. It might not be a large leak.

[dieselguy]

Several owners on this and other brand sites have had creeping slide issues. When the cylinder ram's seals fail (seals on cylinder piston) oil can bypass and allow the slide to creep out after you've retracted them. You'll not see a leak as the leak is internal to the cylinder. Since most any of our units have a closed loop hydraulic system (all cylinders are hooked in one big loop from the pump) … any one of the cylinders can have the piston seal leak and cause any of the slides to creep out … usually the lightest one. There is a procedure to check oil passing past the piston seal, but it takes time (frustration and bigger repair bill) so most techs simply replace all cylinders and move on to the next customer. There is a check valve in the pump assy that can leak, but that is another story. The really sad thing is that every dealer's tech during the walkthrough should point out how to correctly check the fluid reservoir … as many of us can attest … it seldom happens.

[mbbutler]

Originally Posted by SilhouettePenny

Maxima Fork Oil grade 15, for your CC hydraulic system, I get it from Amazon. Also recommended is Torco RFF Grade 15 and Caterpillar Hydraulic Oil Additive #1U-9891, whatever you can source locally. Attachment 201492

Yes, Maxima Fork Oil is best...

[mbbutler]

Originally Posted by NMWildcat

If you have to add fluid because your fluid is too low to work the system, you have leak.

Yes, you have a leak somewhere...on my 33ik, I had two hydraulic lines that were not tightened on the leg next to entry steps.