Single hydraulic slide extends slowly but retracts normally.

[twaggenspack]

I have a 2003 wildcat TT with a single hydraulic slide. The slide extends slowly but retracts normally. I have cleaned and oiled the support rails (logically if the rails were sticky, it seams that it would extend OK and retract slowly). Fluid level is OK, and the slow extension is smooth. Hydraulic motor sounds normal, with no bogging down or racing throughout the cycle. Any ideas?

[bubbles]

Yeah; If it ain't broken, don't fix it.

[twaggenspack]

Does anyone know how the pump operates? Does it electrically reverse to extend and retract or does a valve switch directions and the pump turns in only one direction?

[bubbles]

The pump is reversible. The slide switch reverses polarity, that's why it is a MOM/OFF/MOM switch. Fluid level is checked with slide fully retracted. This is the scenario for a typical hydraulic actuated system (levelers and/or slides).

[twaggenspack]

Thanks Bubbles... That adds another piece to my puzzle. I'm going to run it in and out again to listen to the motor again... Is it possible (anything is possible on an RV..) that the pump may be bad in one direction? Does anyone know the pressure it puts out? I may have a gauge to put on the lines to check for pressure. If not, I'll try to get the model off the motor if I can find it to look it up.


Again, I don't think I have a mechanical bind due to the difference between extend and retract. And because lines flow in both directions, I can rule out a restriction. I'm down to checking the motor, electrical or power of the pump......

[bubbles]

I believe my Lippert system does pressurize to approximately 2700psi. I do have levelers and slides and if my Lippert system pressure does fall to below 1500psi static (power off) then an alarm will sound. I don't know what kind of pressure reading should show while slides in transient (retract/extend). Maybe someone with more knowledge about your particular unit can chime in with more definitive information. I have a motorhome not a trailer. Good luck.

[TitanMike]

Originally Posted by twaggenspack

Thanks Bubbles... That adds another piece to my puzzle. I'm going to run it in and out again to listen to the motor again... Is it possible (anything is possible on an RV..) that the pump may be bad in one direction? Does anyone know the pressure it puts out? I may have a gauge to put on the lines to check for pressure. If not, I'll try to get the model off the motor if I can find it to look it up.


Again, I don't think I have a mechanical bind due to the difference between extend and retract. And because lines flow in both directions, I can rule out a restriction. I'm down to checking the motor, electrical or power of the pump......

I'm not so sure a pump can be bad in one direction and not the other but I do know that it's possible for hydraulic cylinders to be.

If the seal on the cylinder's piston has a bad lip on one side pressurized fluid can pass to the other side bleeding off pressure. Putting pressure on the other side will stop the leak as the lip (if it too isn't damaged) is now stopping any leak/flow to the other side. Most hydraulic cylinders that can be pressurized in both directions have a double lipped seal so that pressure forces the seal against the cylinder wall on the pressure side and merely slides on the other.

One clue to the seal condition might be motor sound when the slide is at full retract or full extend. When a hydraulic cylinder reaches the end of travel pressure goes to max and motor sounds more labored. You can also usually hear the sound of the pressure relief valve bypassing fluid. Kind of like when you turn your steering wheel to one side limit or the other and hear the power steering pump bypass fluid. Try holding the switch down in both positions. If you don't hear a change in the pump sound when it reaches the full out position it's POSSIBLE you have a bad cylinder.

This of course assumes there are no other issues.

[wrapperman]

My understanding is the motor does not run in reverse but different valves operate in the valve body to reverse the flow of fluid causing the cylinders to extend or retract.
We have a 2013 378 XL with Lippert hydraulics.
Please correct me if I'm wrong.
Have you contacted lippert yet. They helped me to diagnose an issue I had once, even after the unit was 5 years old.
Very nice and eager to help. All I had to do was call tech support and they told me what to check for. No waiting for a call back either.
When you find out please let us now.
You may just have a valve that needs to be seated closed manually. Sometimes they do loosen up over time.

[bubbles]

Originally Posted by wrapperman

My understanding is the motor does not run in reverse but different valves operate in the valve body to reverse the flow of fluid causing the cylinders to extend or retract.
We have a 2013 378 XL with Lippert hydraulics.
Please correct me if I'm wrong.

You're wrong. look at your emergency retract/extend for your GT378 slides/levelers. Your system uses a Trombetta type contactor that reverses polarity for the motor to run in both directions. The emergency retract/extend procedure is to use a hand drill with a hex socket in the back of the motor to run it clockwise or counterclockwise for those actions.

[wrapperman]

Originally Posted by bubbles

You're wrong. look at your emergency retract/extend for your GT378 slides/levelers. Your system uses a Trombetta type contactor that reverses polarity for the motor to run in both directions. The emergency retract/extend procedure is to use a hand drill with a hex socket in the back of the motor to run it clockwise or counterclockwise for those actions.

interesting. Mine must be different than yours.
As per Lippert manual it says to run your drill in only one direction and manually open or close the reversing solenoid valve to operate the slide either in or out. Also I just looked at my motor and it had a permanent ground wire from one ot the motor terminal to chassis ground.
I do not have a polarity reversing solenoid but a single solenoid like an auto starter solenoid.

[bubbles]

Originally Posted by wrapperman

interesting. Mine must be different than yours.
As per Lippert manual it says to run your drill in only one direction and manually open or close the reversing solenoid valve to operate the slide either in or out. Also I just looked at my motor and it had a permanent ground wire from one ot the motor terminal to chassis ground.
I do not have a polarity reversing solenoid but a single solenoid like an auto starter solenoid.

Well, I learn something everyday. So I might be able to help others with an issue would you please post the manual or provide google search info.

[wrapperman]

Sure he is a pic of the solenoid. I'll look for the manual and what page it is on.
I said this because just 1 month ago I helped someone retract their jack by this method. He has a 2014 Winnebago with the same Lippert Hydraulic system as mine.
I also traced the ground wire from the motor to the chassis and measured the resistance for that wire to the chassis to make double sure. Let me know if you found something different as I like to know as well. I'll also look deeper into my system and let you know if I'm mistaken.

[twaggenspack]

Well, I took a picture of the pump and looked it up. Mine retracts with a hand crank, so it is different than both of yours. As I stated, anything is possible on an RV...any type!


My pump is a Dewald from Lippert. The pump runs in both directions. Two solenoids determine pump direction. Manual retraction is done with a lug wrench in a manual pump located in between the motor and pump along with a relief valve.





https://support.lci1.com/dewald-slide-out-system

[twaggenspack]

2 questions...


1) I know you can pump the slide back in by turning the knob on the pump and using a lug wrench, pump the slide back in, but how do you extend the slide manually?


2) If the cylinder is bad in the extend direction but good in the retract direction, could I switch the hoses at the pump and conform that the cylinder is bypassing?


Thanks for your help...

[DougW]

Since you are asking I suspect this is a significant difference in speed, if it is only a bit of a difference in speed it would be normal.

As a hydraulic cylinder extends it need enough fluid to fill the full diameter of the cylinder to push the rod out. To retract it needs only enough fluid to fill the area around the rod. Some difference in speed is normal and since these systems use a rather small electric motor the difference in speed is sometimes noticeable because the motor does not move fluid at a high rate.