We're getting ready to pull out on a short trip to Durango, CO only to find the left rear jack is having fits. It lowers but will not extend. The RV dealership had the jack specialist they use take a look and he found oil was needed. That has been corrected but the jack is still not extending. They advised although it is a sealed unit, the tech can drill some holes and repair it. I feel I'm getting the readers digest version of this but he is saying the cost will be $600 per jack and I need two. Any ideas? I don't know why they need to fix two since only one is failing but, although this won't affect our trip, I like things to work correctly. Does anyone know what type of HWH jack system was used in my case? If I need to replace a jack (or two), where is the best place to look that won't make me feel violated when the smoke clears away?

When I hear 'experts, aka techs' say they can fix it by drilling a hole in it, a huge red flag goes up. If there was supposed to be a hole in it, HWH would have made it that way. Call HWH, talk to the people who made the thing, and they'll tell you what to do. If the RV dealership is so sure of how to fix it, get a guaranteed price and a two year, unlimited warranty on their work and materials. My guess is that they'll disappear into the sunset.

I'm with Jim. Never seen an hydraulic thingie fixed by drilling a hole where none was before.

If the system were low on oil, the cylinder might have gotten airlocked, and the dealer's plan is to refill and bleed it through the new holes. But that should be able to be accomplished by disconnecting the hose and adding oil with a small tube...and certainly, jacks aren't like earrings - one shouldn't need a pair...

I went to the dealership and spoke in person with a technician instead of the service writer. It turns out the tech that will fix it actually has to cut the top off of it and rebuild the internals. I'm assuming the top is then welded back on. I don't have any plans of doing this since I can get a new jack from PPL or someone for less, depending on which model jack it is. Having said that, I'm sure the jack I need is actually more expensive than the lobotomy repair job. The upside is having it work as intended.

I'm not so sure that surgery or replacement is necessary, although I'm certainly no expert on HWH (or any other) levellers, nor do I play one on TV. But having been a Navy ship's Chief Engineer and a field engineer with a major oil company, I can say there's not much to go wrong with hydraulic rams, and wear (unlikely in your case) is the usual culprit in failure, and blowby is symptomatic of wear. Even with excessive wear, the jack should at least extend to the ground, although it might not lift the coach.

Try this HWH site; it shows the folddown is activated by a smaller cylinder, then the main extends the jack. I'd suspect that there's a valve or bypass port in the smaller cylinder that routes fluid to the extension cylinder when the jack is fully erect.

There should be an hydraulics shop in your area. If it were I, I'd remove the offending jack and take it to that shop and see if they can figure it out. Many shops will examine it for free, as it's not the usual boring, repetitive stuff they routinely deal with.

I'm just not convinced that jack has actually worn out to where a rebuild is required.

Thanks Rusty, I'm with you! I'll wait and see what they have to say in the morning. The "visiting" tech is supposed to come back and take another look. If I don't get warm fuzzies, I'll take it to a hydraulic shop as you suggest.

Actually, I should have looked more closely at the movie and the routing of the piping. It's apparently a bypass port that opens at the end of the folddown cylinder's stroke that opens, routing fluid to the extension cylinder. Note the external tubing that exits the folddowm cylinder at the bottom, which is routed to the extension cylinder.

I would be more confident in my "reverse engineering" if the fitting on the extension cylinder were mounted higher on that cylinder, but there could be a port routing fluid to the cylinder in the ram itself.

In any event, I'd demand the "visiting" tech produce prints of the design clearly showing the operation, before I'd take his pronouncements as gospel.

I have worked on HWH jacks, and if the fluid was low, air is in the system and it will NOT work correctly until the air is out. NO, didn't drill holes!!

My procedure was to jack the coach up by the axle (bottle jack) as high as I could get it and then put the jack down on that side. Because the side was jacked up the HWH jack could extend quite a bit further then when the coach was in the normal ride condition. Then I would slowly lower the bottle jack down with the HWH jack still extended, then would retract the jack. Air in the system would then be forced out and because there was more fluid behind the air, after a couple of these cycles, the jack HWH jack would start to function normally.

Most leveling jacks are self bleeding but if the fluid was very low, a lot of air in there will take some work to purge.

HTH

That's totally logical - and cheaper and more rational than turning loose a "tech" with a drill or angle grinder.

"My procedure was to jack the coach up by the axle (bottle jack) as high as I could get it and then put the jack down on that side. Because the side was jacked up the HWH jack could extend quite a bit further then when the coach was in the ..."
Caution: RV lore says NOT to jack up (only) one corner; the dreaded frame twist/crack/break may occur (not to mention the interior items which may fall off or refuse to open evermore).

Actually, this is the first time I've had a complaint with this RV dealership. When I scheduled it for service over three weeks ago, I told them the jack was the most important thing other than de-winterization. They had this tech out to work on four other jacks yesterday and didn't even have him check mine. Mine wasn't even on the list. Now he is booked up with the other jacks. Here we leaving on Friday morning, they've had the coach since Saturday and, out of four things scheduled, only the de-winteizing has been accomplished. I think I'll take a copy of these postings in and see what they say about the jacks. The phone isn't getting the results I need. Armed with a bit of information here, I think this might do the trick.

quote:

Caution: RV lore says NOT to jack up (only) one corner; the dreaded frame twist/crack/break may occur (not to mention the interior items which may fall off or refuse to open evermore).

So does that mean you can't go over a curb with one wheel without twisting the frame?? That is what this amounts to!

You are right--- it is "lore"!

My Southwind would pop its windshield if driven on unlevel camp sites. Both for previous owner and me. It popped its windshield for the current owner in really strong winds. His RV repair place used through-bolts to sanwich 1-inch flat stock in front of and behind the divider strip to help hold things together.

quote:

Originally posted by bill h:
My Southwind would pop its windshield if driven on unlevel camp sites. Both for previous owner and me. It popped its windshield for the current owner in really strong winds. His RV repair place used through-bolts to sanwich 1-inch flat stock in front of and behind the divider strip to help hold things together.

Who said parallelogram going down the road?

"So does that mean you can't go over a curb with one wheel without twisting the frame?? That is what this amounts to!"
Welll... Tire sidewall flex, shocks, springs, wheel travel, all ameliorate the potential problem when a wheel rolls over a curb. Myth or fact, I wouldn't (don't) do it.