Slideout hydraulic line selector-knob stripped

[howson]

Yup. As I searched more, I realized that the collet is part of a larger assembly. On my own, I found several styles of drill chucks that are relatively inexpensive. Still trying to come up with ideas. The epoxy/cold weld idea is becoming less appealing. If it doesn't work, i will have messed up pretty bad.

Does anyone know if the hydraulic lines are under pressure. I assume not, but if I remove the valve, I should expect leakage -- and I assume I'll need to bleed the line somehow. Sounds like an awful job.

-Steve

Chad covers R2 the hydraulic valve in this video. He was surprised how easy it was to do.

[steve&renee]

I took the earlier suggestion to call Lippert about ordering parts. Lippert told me they make the hydraulics, but Grand Design installs the valves -- so I should call GD. Did that yesterday, and sure enough, the GD parts department found the part number (and a picture) of the manifold/valve assembly that has the knobs. It's a Lippert assembly!

So with the GD supplied Lippert assembly part number in hand, I googled. The assembly is available from several sources -- from $145 - $180. Ouch.

Then I called Lippert again. Got to their parts department, and they had sub-part numbers for the assembly parts. And yes they have knobs. Two knobs in stock. $2.95 each. I ordered both, and with shipping, they charged me almost $20 bucks.

Now I have a question: when the knobs come in and I go to put one back on the stem, should I epoxy/cold weld the knob in place? The reason the original knob stripped is the valves get frozen/stuck with lack of use -- like over the winter for example. With clean flutes in a new knob, I'm leaning toward cold welding. . .

-Steve

[Cate&Rob]

steve&renee

Going back to your pictures with post 1 . . . the grooves on the brass shaft are filled with the plastic stripped from the original knob. The brass does not look to be damaged. I would carefully clean the grooves of the shaft and try for an “as new” fit with the new knob. (No added glue). The “learning” is that you have to be very gentle with this valve.

Rob

[Country Campers]

I would also clean the "threads" on the shaft , use a small brass tooth brush if you have one. I am curious if you could spay these threads with the ptfe dry lube to keep them moving freely. Just a thought to try to put off future problems. The threaded portion should just travel thru the nut that is shown in your picture , there should be a seal of some kind there, maybe just some packing gland material.

Brian

[steve&renee]

My knobs came in from Lippert this weekend. Here's my experience getting the valves functional again.

For the last couple of days, I've been spraying the valves with penetrating oil. Still couldn't turn the valve with knob still attached by hand, so I used some vice-grips perpendicular to the knob axis to get some additional angular force. The added force broke the valve free, and while it was stiff, I could turn it all the way from open to closed. More penetrating oil and operating the valve, and the operation of that valve was satisfactory.

Moving on to the valve that needs a knob. I discovered that the new knob had no grooves to receive the splines. It's just a slightly undersized hole. To install the knob, start it onto the valve stem and tap the knob with a hammer. The stem splines make their own grooves.

With the new knob in place, I tried to operated the valve. Frozen solid. Used my vice-grips as before. Stripped the knob. In frustration, I tried to turn the stem with my vice grips. Frozen solid.

So if you look at the picture in post #1, there's a 9/16" nut holding the valve into the manifold. Decided I had no choice but to loosen that nut -- and hope I didn't get a mouth full of hydraulic fluid.

There was just a drop of fluid, and the whole valve/valve-stem came out as one piece. This was good. I took the valve to my workbench and placed it vertically in a vice. More penetrating oil and better tools, and I finally broke the valve-stem free. Got it so the valve-stem was turning really freely. And with it turning that freely, the knob fit securely enough that it was still usable.

Got the valve and knob reinstalled, and operated both to confirm the original slide-control functionality. Works as expected.

One thing I learned that may help someone else out. Once you extend the slides, the hydraulic lines are under enough pressure that the valves are quite difficult to operate. There should be a WARNING: DO NOT OPERATE VALVES WITH SLIDES EXTENDED - YOU MIGHT LOSE YOUR KNOB.

The other thing I did that I think everyone should do: When you open the valves for normal slide operation, don't open until the valve-stems reach a full, hard stop. That's probably what led them sticking open initially. Also, operate the valves frequently, and lubricate.

-Steve