Changing hydraulic fluid

mikkeeh · 08-05-2014, 02:24 PM

I saw in the owners manual that it is suggested to change the hydraulic fluid every 3 yrs. Is there a port to drain the fluid??? Cant seem to find any info on it. Thx

Truman · 09-02-2014, 09:07 AM

I used a small hand transfer pump, cost about $5 at Harbor Freight, or you can use a small tube and siphon oil out. Manual said about 2 quarts of fluid but mine took 3.

Thurman · 09-02-2014, 09:38 PM

I just have to ask being as I have worked with hydraulics all my life. Why would you have to change the hydraulic fluid? As stated I have worked with units that ran for twenty (20) or more years and never changed the hydraulic fluid. Change the filter on a periodic basis--Yes. Is there not a filter on the hydraulic units for RV slides?

mikkeeh · 09-02-2014, 09:49 PM

Quote:

Originally Posted by Thurman

I just have to ask being as I have worked with hydraulics all my life. Why would you have to change the hydraulic fluid? As stated I have worked with units that ran for twenty (20) or more years and never changed the hydraulic fluid. Change the filter on a periodic basis--Yes. Is there not a filter on the hydraulic units for RV slides?

Well...that's a good question. I read in the owners manual that Lippert recommends changing the fluid every 36 months. There is no filter as far as I know. I assumed that maybe the fluid absorbed moisture over time.....but I don't really know. They must have some basis for requiring a fluid change??

lbrunning · 09-02-2014, 09:57 PM

The only filter in this type of hydraulic system is a screen on the suction side of the pump and the tank is vented to atmosphere so the oil will get some moisture and dirt in it over time

win · 09-02-2014, 10:36 PM

I agree with Thurman , IMO it's a waist of time and money
The vent is actually a breather with a filter
Question for you guys. Do any of you change your power steering fluid every 3 years in your car or truck, I doubt it
But do what you have to do I guess

Sent from my iPhone using Forest River Forums

B47 · 09-02-2014, 11:07 PM

I tend to agree with those who question why change the hydraulic fluid in RV's.

The Boeing 727 ran a 3,000 psi hydraulic system ( I think the newer transport airplanes are even higher) and the airline was strict regarding changing the fluid and filters based on operating time. But these are powerful systems.

Most hydraulic systems in TT's,FW's, Toy Haulers, MH's are far less powerful and run many less hydraulic components,so I also have to question the need to change the fluid.

I don't have an issue with changing the filter(s).

ezawacki · 05-04-2021, 01:01 PM

I was on the phone with Lippert last week (26 April 2021) asking about how to manually open and close the slides on a 2013 Sierra 365SAQ. During the conversation the tech mentioned that Lippert recommends changing the fluid in the reservoir every 5 years. ATF fluid.
Now I'm acquainted with hydraulic fluid from my days in the P-3 Orion, even though I wasn't an AMH. I had to think about it if hydraulic fluid expires or gets old after 5 years. I always went by the color or the smell method. Anyway, that all said I decided to change it anyway. Honestly I don't think that I would have considered changing it if it wasn't mentioned.
I don't have any issue with the slides hope it stays that way. One of my favorite sayings is if its not broke don't fix it.

jd4010 · 05-04-2021, 01:43 PM

Personally, I wouldn't worry about changing the oil. Here's why:
1) Hydraulic fluid and ATF are not hygroscopic
2) The oil in these systems probably rarely goes above ambient temps unlike a transmission, power steering system, etc that can easily go 175 to 200+ degrees. Hence, it doesn't break down as fast or even at all

The only time I would change the oil is if the oil was contaminated. For example, when I bought my 2019 5er, didn't realize the hydraulic oil reservoir was missing the cap until 2020. Ugh. So I got a new cap, drained and refilled the system.

ezawacki · 05-04-2021, 02:19 PM

Quote:

Originally Posted by jd4010

Personally, I wouldn't worry about changing the oil. Here's why:
1) Hydraulic fluid and ATF are not hygroscopic
2) The oil in these systems probably rarely goes above ambient temps unlike a transmission, power steering system, etc that can easily go 175 to 200+ degrees. Hence, it doesn't break down as fast or even at all

The only time I would change the oil is if the oil was contaminated. For example, when I bought my 2019 5er, didn't realize the hydraulic oil reservoir was missing the cap until 2020. Ugh. So I got a new cap, drained and refilled the system.

Totally understand that. In tune with the same thoughts. Makes me wonder why they (Lippert) would recommend that maintenance task.

Scrapper · 05-04-2021, 03:02 PM

Even though hydraulic fluid and ATF are not hygroscopic you still have contaminates from wear to the pump, valves, seals, ram components and hoses. Most of the particles settle to the bottom of the reservoir but you still have microscopic contaminates which stay in suspension and create more wear on the parts the fluid flows through. It then becomes a vicious cycle the longer the fluid remains in the system. It helps if there is a filter like your engine has that the fluid flows through on the return line but most small hydraulic systems just have a screen on the pickup tube inside the reservoir tank.

ezawacki · 05-04-2021, 03:19 PM

Quote:

Originally Posted by Scrapper

Even though hydraulic fluid and ATF are not hygroscopic you still have contaminates from wear to the pump, valves, seals, ram components and hoses. Most of the particles settle to the bottom of the reservoir but you still have microscopic contaminates which stay in suspension and create more wear on the parts the fluid flows through. It then becomes a vicious cycle the longer the fluid remains in the system. It helps if there is a filter like your engine has that the fluid flows through on the return line but most small hydraulic systems just have a screen on the pickup tube inside the reservoir tank.

I'll look to see what my hyd system has.

5picker · 05-04-2021, 03:27 PM

If you have contaminates in your hydraulic system from the pump, seals, rams or hoses, you got bigger fish to fry.

I would never worry about changing it. Lippert recommends it so if 6 years down the road, you actually do have an issue for some unknown reason, they can deny any responsibility by stating you didn't change the fluid as recommended by the factory.

Scrapper · 05-04-2021, 05:22 PM

Quote:

Originally Posted by 5picker

If you have contaminates in your hydraulic system from the pump, seals, rams or hoses, you got bigger fish to fry.

I would never worry about changing it. Lippert recommends it so if 6 years down the road, you actually do have an issue for some unknown reason, they can deny any responsibility by stating you didn't change the fluid as recommended by the factory.

I forgot to mention dust/dirt collecting on the ram then being pulled into the seals when retracting the slides or levelers. The dust/dirt grinds away at the ram seals allowing what starts out as un-noticable leakage which gathers more dust/dirt causing more leakage. Once past the seals on the rams the dust/dirt starts grinding away at seals and seats in the valves along with the seals and pistons or vanes in the pump. If your rv has an older style gear pump then dust/dirt becomes more critical.

Dirt and dust is the enemy of any hydraulic system and the wear it causes on the system is just the way it is.

Then you have the wear and tear on the hydraulic hoses caused by flexing which can cause the inner lining to crack and break allowing plastic/rubber particles in the fluid.

Over 26 years working with hydraulic systems on the car shredder, forklifts, end loaders and rubber-tired and crawler cranes has taught me something even if it is oil tastes bad when getting an oil bath from a blown hose or ruptured pipe.

ezawacki · 05-07-2021, 12:30 PM

Well, I changed my hydraulic fluid anyway. I didn't want to do it and agree with the thought of if its not broke then don't fix it. The only reason I did it was because I already bought the fluid and thought might as well do it. Also with the fluid I bought a siphon from amazon. The removal of the fluid with the siphon went slow but steady. By the time I got to the bottom I could see grime/dirt at the bottom. Wasn't sure if it was dirt so I focused the siphon hose towards the corner and sure enough it sucked up some dirt. Got as much out as I could. In the photo attached you can see the dirt at the bottom and the clear part that was already removed with he siphon. It was hard to focus the camera through the hole. Refilled the reservoir with ~ seven quarts of fluid. Cycled the slides a couple of times. Works good.

Some remarks: Trailer is a 2013 FR Sierra 365 SAQ. There were no issues with the slides or landing gear. The color of the old fluid was a dark red. The color of the new fluid was like a bright red in comparison. Lippert said it would take 7 quarts to refill and they were right on. Slides seemed to perform better after refilled with new fluid.

Scrapper · 05-07-2021, 08:42 PM

Quote:

Originally Posted by ezawacki

Well, I changed my hydraulic fluid anyway. I didn't want to do it and agree with the thought of if its not broke then don't fix it. The only reason I did it was because I already bought the fluid and thought might as well do it. Also with the fluid I bought a siphon from amazon. The removal of the fluid with the siphon went slow but steady. By the time I got to the bottom I could see grime/dirt at the bottom. Wasn't sure if it was dirt so I focused the siphon hose towards the corner and sure enough it sucked up some dirt. Got as much out as I could. In the photo attached you can see the dirt at the bottom and the clear part that was already removed with he siphon. It was hard to focus the camera through the hole. Refilled the reservoir with ~ seven quarts of fluid. Cycled the slides a couple of times. Works good.

Some remarks: Trailer is a 2013 FR Sierra 365 SAQ. There were no issues with the slides or landing gear. The color of the old fluid was a dark red. The color of the new fluid was like a bright red in comparison. Lippert said it would take 7 quarts to refill and they were right on. Slides seemed to perform better after refilled with new fluid.

If you didn't get rid of the old fluid you could pour it over a magnet, if it has steel/iron particles the magnet will attract them. It's not going to tell you the dirt is not some other contaminate but it will let you know if the pump or valve has wear.

Larger hydraulic reservoir tanks have a drain plug with a magnet built in to catch metal contaminants but most small hydraulic units don't have a drain plug near the bottom of the reservoir. The metal contaminates the magnetic drain plug catch is so fine it looks like graphite powder when spread on a sheet of white paper or rag. I believe an add-on hydraulic filter would do wonders even on a unit such as in your rv.

https://www.amazon.com/LENZ-Spin-Fil...NsaWNrPXRydWU=

ezawacki · 05-08-2021, 10:29 AM

Quote:

Originally Posted by Scrapper

If you didn't get rid of the old fluid you could pour it over a magnet, if it has steel/iron particles the magnet will attract them. It's not going to tell you the dirt is not some other contaminate but it will let you know if the pump or valve has wear.

Larger hydraulic reservoir tanks have a drain plug with a magnet built in to catch metal contaminants but most small hydraulic units don't have a drain plug near the bottom of the reservoir. The metal contaminates the magnetic drain plug catch is so fine it looks like graphite powder when spread on a sheet of white paper or rag. I believe an add-on hydraulic filter would do wonders even on a unit such as in your rv.

https://www.amazon.com/LENZ-Spin-Fil...NsaWNrPXRydWU=

Scrapper,

Looking for a magnet now. I still have the old fluid in a container in the back of the truck. I like the idea of the add on hyd filter. I'm gonna look into it. Thanks..

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