Winnebago HWH Hycraulics

IMO the odds are pretty good that the problem is either a lack of hydraulic fluid or a bad solenoid.

checking the level of hydraulic fluid in the tank is simple. retract all rooms and jacks before checking. use a clean cloth or paper towel to wipe the dipstick after removal and then dip it again. since the other jacks are working and the reluctant jack is in front, I'm betting that you do have enough hydraulic fluid in the tank but it's an EZ first step.

the owner's manual should have a diagram that shows which solenoid is which. if not then you might want to give Winnebago Tech Support a call. They're very good at helping owners diagnose problems. 1-800-537-1885. You'll need either the VIN of the chassis or the serial number of the coach. both should be on a placard inside the coach or on your owner's manual.

Once you've identified the solenoid make sure that it is closed tightly. Since you have the part have the tech replace it and then test the jacks. if it were me, I'd watch him make the swap. If the jack still doesn't work have him explain, in detail and in plain English, what he means about a "valve". another possibility is a bad jack. the jack might be damaged, or dirt might be preventing it from fully extending. those are possibilities but, in my experience,34-seasons, it is most likely the solenoid.

good luck and safe travels.

https://anyrvparts.com/products/hwh-rap0642-oem-rv-12-volt-2-5-325-series-hydraulic-leveling-jack-solenoid-valve-cylindrical-body-cam-release-replacement-part

This link shows what the solenoid looks like.

https://www.rvtechlibrary.com/chassis/HydraulicsandHWHSystems.pdf

Page 28 shows how to tell which solenoid is which. You look at the solenoids from THEIR side. The center ones are the front jacks the outer ones are the rear jacks.

Now, you have changed your statement. You originally stated the RF jack would not operate, then you stated it came down 2 or 3 inches. Which is it? There are NOT 8 solenoids for the jacks. ONLY 4 for the jacks. Which are mounted side by side. If you have other solenoids, then those are for the Slide out rooms 2 solenoids per room. These are mounted on EACH SIDE of the HWH manifold and are BELOW the 4 jack solenoids.
IF the jack will NOT retract fully in STORE mode, you need to release the T handle(old 2004 solenoids have these) on all 4 solenoids. Newer oones have the spring loaded release. This will open up all 4 solenoids and see if the jack retracts(all 4). With the manual release open, if one jack(RF) fails to retract, you need to use a pry bar like an 8 foot 2x4 to lever it fully retracted. IFTHIS RETRACTS THIS JACK, The jack cylinder needs replaced/Rebuilt as the inner seals are bad. This is a seperate problem from NOT extending. Now, IF you have the manual solenoid releases open and you operate the pump, all 4 jacks should extend while the pump is running. Have someone observe this while somebody operates the jack pad. It will take a few minutes for all 4 jacks to extend and hit the ground. IF you stop the pump before they extend fully, the jacks will retract(all 4). IF the RF jack extends fully, then the solenoid is the problem. BUT, It can be 2 problems. The fuse for it is blown and sends no signal to open the solenoid. OR, the jack solenoid electrically is bad. A BAD solenoid will sometimes blow its fuse. So, replacing the solenoid is the thing to do since you already have it. Doug

Doug I'm so sorry. Thank you so much for this information. I guess it makes a difference if it doesn't extend or it only extends 2 or 3". This last time it would only extend 1". I have blocks piled up from the ground but it won't extend enough to get the coach perfectly level from side to side. It's off my an inch or two. But level front to back.

Does the RF jack FULLY retract? No shiny part visible. THIS IS IMPORTANT
Are you using Auto Level?
Have you tried to manually extend just the front jacks?
IF just extending the front jacks AND both jacks fully extend, then your fluid level would come into question. Doug

Doug, Last time I tried the jack did Fully retract. I am using the auto level sort of. I check with a level inside and raise the front or rear or one side or the other as needed. The passenger front jack will not extend just extending the front jacks or the side jacks. Does that help clarify?

SINCE YOU HAVE THE SOLENOID, REPLACE IT. If it still does not extend check the RF jack fuse. Doug

I can not help directly but I believe this link may help

https://www.winnebago.com/Files/Files/Winnebago/Resources/Diagram/Wiring.htm

Also you may want to go over to the Winnebago owner forum for some good info also

https://www.winnieowners.com/forums