Hydraulic slideout

[biomedical247]

My 2021 alpine 3700fl will not alow me to retract the kitchen or the dining room slide-out. I can deploy them but when I try and bring them in they will not work. I hear the pump running but no movement so I have to loosen the hydraulic hose and manually bring them in. Any ideas.

[chuckster57]

Welcome to the forum

Do you know which hydraulic system you have? I believe there are 2 different ones and troubleshooting is different.

[ChuckS]

Your hydraulic slide system on your 2021 Alpine can be either Lippert ot the Equailzer system

Starting in 2021 some Alpines came with the equalizer hydraulic system

Your problem IS..
The Hydac valve is not opening to allow fluid flow when you try to retract the slides ..

If this is the Equalizer system outside in the pump compartment there is a bank of 10 amp fuses.

One of those could also be blown not allowing the Hydac valve to receive power to open when the retract mode is selected.

Lippert hydrauilc system is different and does not have those fuses..

If you have the Lippert hydraulic system then the issue is STILL the Hydac valve is not opening when you select retract mode for slides

The SMARTER way to allow the slid2s to retract is to manually open that Hydac valve with an Allen wrench before you select to retract those slides and then manually close the Hydac valve

[biomedical247]

Hydragear system

[ChuckS]

Originally Posted by biomedical247

Hydragear system

You have the wrong info.. Alpines came with Lippert and some 2021 units have the Equalizer system..

There is NO Hydragear hydrauilc system on any Keystone Alpine ever made

[ChuckS]

The attached image shows both the Lippert hydrauilc pump and the Equalizer Systems pump.

The Hydac valves are mounted directly to the pump manifold on the Equalizer Hudraulic system .. bottom image and Lippert Hydrauilc system has the Hydac valves mounted on separate manifolds not attached to the pump

[ChuckS]

Once you let me know what hydraulic system you actually have I can help you to locate the Hydac valve for the slides so you can manually open to retract the hydraulic slides.

That FL model Alpine also has at least TWO slides that are electrical driven and they are the Schwintek in wall slides

[biomedical247]

Equalizer hydraulic system. They have it mounted vertically. The valves sit on top of the tank not horizontal like the picture.

[biomedical247]

To bring the slide in I loosened s1 and s2 hydraulic line and as I ratchet in the sides the fluid drained into a container placed under them. When the slides were in I reconnected the lines. When I got to my new campsite I pushed the slide-out button and the slides automatically slid out. Note: I did replace the expelled fluid with new fluid before sliding out. But now they will not slide in.

[ChuckS]

Now that we know you habe the Equalizer Hydrauilc system in your 2021:Alpine the issue you have is NO 12 volt power to the solenoid that is mounted with the Hydac valve that opens and closes to allow the slides to move

You have normal operation in the extend motion so the Hydac valve and solenoid are both GOOD

You are NOT getting 12 volts DC to the Hydac solenoid when you select retract..

There is a bank of fuses located in your hydraulic compartment for slide out control

Check each one

Also your motion command to extend or retract the hydraulic slides passes thru the In Command Display to the BCM and the BCM sends the extend or retract signal to the pump motor and Hydac solenoid valve

You can locate the Hydac valve for the slides and on the end is a small Allen head screw..

This is for manual override if the system has a failure

Simply open the correct Hydac valve before you want to retract the slides and then operate normally via your display tablet

Close that small Allen head screw when sldies are in

The way you are doing it now IS INDUCING A LOT OF AIR INTK THE ENTIRE HYDRAULIC SYSTEM

This will cause you all sorts of problems with both the slides and six point hydraulic leveling system sooner or later.

The system is self purging though so you can run the slides and levelers a few times to expel the air

Edited post….
The hydraulic slides are connected in tandem so there is only ONE Hydac valve that needs to be opened manually to allow,slides to be retracted using the hyd pump

[ChuckS]

In this pic you will see S1 and S2 hydraulic lines .. the yellow arrows point tio the Hydac valves that must electrically open when you select retract for the hydraulic slides

I had to double check what I told you earlier and it appears the Equalizer Hydraulic system is using two Hydac valves for the slides..which is stupid

Picture for reference

If this is the case then on the end of each of those Hydac valves .. S1 and S2 is an Allen head screw.l

Simply open it before you wish to retract the slides and when slides are closed then close both Hydac manual over ride valves

[biomedical247]

Ok thanks I will check it out. Undoing the Allen screw bypasses the solenoid valve? It allows the fluid to flow back into the tank correct? So if I follow you even though the pump is running the fuse to the solenoid retract may be blown and not allowing flow?

[ChuckS]

When you manually open that manual override screw then it allows fluid to flow past the valve thru the lines to move the hydrauilc slide with the pump motor running

Manually closing the Hydac valves after OEM stop the pump running then holds the slides in their retracted position

Your issue is both Hydac solenoids for S1 and S2 return lines is not opening when you retract the slides .. hence the pump runs but slides won’t move

You need o backtrack both solenoid wires for the retract signal side to find out where you have lost 12 volts signal

Equalizer system uses an interface box located inside the pump compartment door for this and it is also interacted to the BCM for the in command system

Hope that helps you

[biomedical247]

It does thank you

[ChuckS]

This is a good clear image of S1 and S2 Hydac valves and solenoids .. arrows point to the small Allen head screw to open on each one before you want to run the hyd pump motor to close the slides..

On the end of each solenoid are two wires..

One is common ground.. the other two are fed over to a fuse block inside the hud compartment and should be fused .. I believe

These two wires must receive 12 volts when you select slide retract from In Command tablet so that they can electrically open the Hydac valves and allow fluid to flow to move the slides in

[ChuckS]

This is an image of the fuse bank you are looking for

[JRTJH]

ChuckS,

In your post #15, (the post with the photo of the two Allen head screws), there are two "inline fuse holders". One is yellow and clearly visible, the other is red and tucked down behind the Hydac valves. Do you know what those fuses are for ?? I remember seeing them, but never searched to see where those wires actually go.

[ChuckS]

Originally Posted by JRTJH

ChuckS,

In your post #15, (the post with the photo of the two Allen head screws), there are two "inline fuse holders". One is yellow and clearly visible, the other is red and tucked down behind the Hydac valves. Do you know what those fuses are for ?? I remember seeing them, but never searched to see where those wires actually go.

Sadly I would be guessing at what those two ATC fuse holders supply power to. The gauge of the wire is more than what is needed for a signal wire to a valve so I am gonna guess and say they might be for the solenoid circuit for the pump motor

I asked Keystone Alpine division many moons ago for more info on the Alpines they installed the Equalizer system on. Their response was not too helpful.. They used a third party install on this system on the Alpines they decided to try this system with.

I also contacted Equalizer Systems and their email response was.. And I Quote " We sold the hydraulic components to Keystone and how they installed it and what controls are used are known only by Keystone".. we only sold them the components