Hydraulic Slides alarming out

[Grammy&Grandad]

The bold part of your reply......That is totally normal. Both slides are hooked up on the same hydraulic lines and as the system starts, the lines are pressurized. The slides each have a different weight and the slide that is the lightest will keep moving in or out, whichever direction you are trying to put them. Once that slide has completely cycled, the hydraulic pressure with then cause the other slide to move to it's full stroke......again, perfectly normal.

One other thing comes to mind here, and I'm just throwing it out there as a possibility. If one of the solenoids in the hydraulic system is NOT fully opening when it is supposed to, in effect partially blocking the hydraulic line, that would be similar to a hydraulic system "dead heading". If you are familiar with that term, you will understand exactly what I'm talking about. If not, it simply means that the pump is trying to move hydraulic fluid and since the flow is restricted, the pump is working harder than it should be. The result of that is the motor current goes up and possibly to the point of drawing enough current to kick out the 80A breaker. As I stated in my previous response, the current is already around 70 amps when the pump is operating the landing gears. Some additional blockage of the line (a solenoid partially closed when it should be fully open) might just be enough to cause an issue with high current on the motor circuit. Like I said, not saying that IS the problem, but just another possibility to explore.

Xrated makes a very good point. And it is surprising that Techs sometimes don't know to check for partially closed solenoids or isolation valves as described! I had a landing gear issue in the shop once and they called me to report that they were stumped why the system would not retract. I reminded them that I had closed the Solenoid to be able to retract manually in order to tow in to them. They were a little embarassed...I would think that this is a common check when hydraulics don't or partially work.

It is easy to check that all the solenoids or open completely - and I'd check all of them, plus take traveldawg's suggestion to make sure those isolation valves are fixed correctly so that you are getting full-open fluid flow in the lines.

[[email protected]]

We ran into this problem while closing the trailer up in 32F conditions for the first time this year. We generally try to avoid closing things up in the snow, but it was unavoidable. I already knew about the problem, so I let the factory breaker cool and after a couple of tries got everything closed up. I already have the replacement breaker, so it will be installed in a week or two when I have time.

[screamineagle]

was your factory breaker a 50 amp or a 80 amp?

[[email protected]]

2016 build date so it's the 50A.

[FT4NOW]

@screamineagle , you mentioned no leaks, there is a possibility of leaks where the hydraulic lines connect to the slide cylinders, you wouldn't be able to see those connections without dropping the coroplast. I'm not saying you should drop the coroplast just to check, but it wouldn't hurt checking if you were down there anyway.

I wonder if it could be a problem with the main electronic unit from the MyRV system. Maybe there is something that it "thinks" it is seeing and reporting a fault code. I dont know if that could be tested or if LCI considered that as a possibility when you spoke to them.

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[Thumper111]

Good morning, here is the current update.
I contacted Lippert, grand design steered me that way. he gave me a gambit of tests to run. I was trying to avoid taking it to the dealer. I was working fine last year when it was put into storage.
Unplugged from shore power or plugged into power it does the same thing, Static voltage on the battery was 12.7 volts. Running the slides it drops to about 12.4. When the slides drop out ( FAULT OCCURED is the message) The voltage continues to hold. They were suspicious of a weak battery ( Brand new Interstate group 27 SRM27, 600CCA, 750 MCA, 160RC.) I do a lot of business with interstate so I contacted my source and he had me bring the battery in to check it out. He exchanged the battery for a new one that checked higher voltage static over 13 volts. I bought a second battery and installed in the system. The unit does have the 80 amp breaker in it. All the tests that Lippert could walk me through voltage wise were fine. I also checked and tightened all connections
In the system. Fluid level is fine, I did add fluid last night. Last night after adding fluid I actually got the slides to work good about 4 times in a row. Thought I had it. Walked away came back, cycled and Fault.
The one thing that makes me suspicious is the fact that when I bring the slides in they are supposed to come in one at a time. they do not do this cleanly, One starts moving and the other moves slightly or stops until the other is done. I did not see this when I took delivery. Also I did not mention before that I hooked the vehicle to the fifth wheel a month ago on a nice day to do a short road trip to test the pullrite 4452 adapter with my 2915 hitch. Took it to a parking lot to check cab and box clearances.
I had problems with the leveling system also faulting out. It took me about 3 times of resetting it to get it to go to hitch height or auto level. I'm getting pretty frustrated with this and the rig is going to the dealer next week. But I'm not stupid, mechanical engineer, mechanic, toolmaker. Been around the block. But it is my first 5th wheel with all the bells and whistles.

So in the nutshell in my eyes:
Its not a battery problem, new battery and an additional one installed.
Its still cold here in upstate NY, but this unit is supposed to be capable of 4 seasons.
There are no leaks that I can see.
All connections are tight.

I'm frustrated!!!!!!!!! Ive got $140K in equipment that I am struggling with and spring is here.
Brand new 5th with hydraulic problems
Brand new 2020 diesel GM that I cannot get to recognize the 5th wheel in the factory tow system
Brand new hitch that I have to buy additional adapters to make it work

UHG!

And Lippert has now kicked it back to Grand Design.

I had a similar problem with my 2020 377MBS, being an electrical guy my first suspicion was the breaker, dealer changed it to the 80 amp but it was a piece of junk in my opinion. I purchased a good quality resettable 80 amp breaker and it helped a bit but not to my liking. I removed the wire between the battery and the breaker and the breaker and the pump. The factory wire is only #6 , I replaced it with some #2 battery or welding cable, this completely eliminated the problem except on very cold days, like -0C or below. you can get additives to add to the reservoir that will keep the oil from getting thicker, cycle a few times to get it through the system and it operates like it should. Just some suggestions good luck moving forward.

[xrated]

I had a similar problem with my 2020 377MBS, being an electrical guy my first suspicion was the breaker, dealer changed it to the 80 amp but it was a piece of junk in my opinion. I purchased a good quality resettable 80 amp breaker and it helped a bit but not to my liking. I removed the wire between the battery and the breaker and the breaker and the pump. The factory wire is only #6 , I replaced it with some #2 battery or welding cable, this completely eliminated the problem except on very cold days, like -0C or below. you can get additives to add to the reservoir that will keep the oil from getting thicker, cycle a few times to get it through the system and it operates like it should. Just some suggestions good luck moving forward.

I upped the wiring also when I switched out the 50A to the 80A breaker. Just make sure that ALL of the pump circuit wiring is upgraded.....battery to the breaker, breaker to the direction contactor, and the ground cable that is from the pump motor to the ground. Any one of those three wire that aren't upsized will be a bottleneck in the pump circuit.