Leveling jack routinely binds up

[memphis02]

Just wondering if anyone has suggestions on what to do about it or know specifically what is causing it?

I originally thought it had to do with what Robbyr refers to as the "airliner creep" where the whole coach wants to roll forward when lowering it off the jacks onto the suspension. I'm still not totally convinced that 'that' isn't the issue and is either binding the jack or causing an air bubble / vacuum in the jack. I do tend to take special care to chock the wheels and remove all air from the suspension, though.

Since this seems to happen to only one jack (Front Driver Side), I thought I'd ask the group for suggestions as it has been happening a bit more frequently, lately.

The problem description is as follows: Picking up the jacks by hitting 'retract' on the bigfoot cp will result in all but the aforementioned retracting. It will raise about 1/16" of an inch off the block, then stop. The pump runs, however, will not lift the leg. I am able to lift the front up with the opposing jack, crib the affected one, lower the opposing jack, forcing the affected one up. Normally after doing this procedure once or twice, the jack will raise and lower as normal.

To me, it sounds like either the cylinder is bound up by the lateral motion from the suspension OR it's getting a slug of air somehow causing the pump to cavitate or lose prime.

thoughts?

[Jagiven]

Could be a number of things if it is just one cylinder. Could be a bend, miss alignment within the cylinder assembly itself. Pneumatic and hydraulic cylinders are very similar to each other. Pneumatic are much more common, I would try a few google searches and you can find some good results.

First thing I would consider is spraying a lubricant on the cylinder, when it is fully extended. What to use? that is the real question, as you do not want to contaminate the hydraulic fluid.

[RVermont]

I have replied a couple times but keep getting kicked out. So I must be too verbose.

On my 2018 the drivers side retract hose is fed from the passenger side cylinder. So from a supply perspective if one works the other should too. Do you have switches on your cylinder? On mine there are no switches on the cylinders. The retract position is sensed by a build up of hydraulic pressure which triggers a switch at the pump.

If you have switchs on each cylinder you probably have individual supply lines.

Is it possible one of the manual valves is set incorrectly? This would prevent the unit from building pressure.



Sent from my iPhone using Tapatalk

[RVermont]

To complete my thoughts. If your unit is similar to mine with a pressure switch. A bound piston would allow the pressure to build and the pump would stop with the foot still being in the lower position. So if the pump is running and not moving it could be air or lack of fluid or a valve that is not operating correctly.


Sent from my iPhone using Tapatalk

[Robbbyr]

Originally Posted by RVermont

On my 2018 the drivers side retract hose is fed from the passenger side cylinder. So from a supply perspective if one works the other should too. Do you have switches on your cylinder? On mine there are no switches on the cylinders. The retract position is sensed by a build up of hydraulic pressure which triggers a switch at the pump.

If you have switchs on each cylinder you probably have individual supply lines.

Is it possible one of the manual valves is set incorrectly? This would prevent the unit from building pressure.

The older Seneca models use the Bigfoot leveler system, each jack has its own separate pump/hose/oil tank assembly. They are not linked hydraulically, but each is tied in electrically to the control assembly. There are no bypass valves as in some other type leveler systems.

Memphis - I am guessing you have checked the fluid level in that jack's tank, you need to remove the cover on the pump assembly to get to the tank and the fill cap. Definitely requires a trip under the rig to do that!

If the hydraulic tank has fluid in it (it may not be all the way "full" if jack is down) and the pump is running trying to lift it, I fear it could be a binding cylinder. When I have talked to Bigfoot they were very aware of our Seneca's installation, telling me previously that Jayco should have installed an air dump system and should have gone with larger cylinders to better withstand the creep forces introduced by our rear air suspensions.

Having said that, I have found Bigfoot's willingness to discuss issues outstanding, even when out of warranty. If they/you narrow it down to a cylinder issue, it may still be in warranty for the cylinder itself. Have your Bigfoot serial number available when you call, should have been a sticker on the control panel.

Good luck, let us know what they determine. Us other Bigfoot owners may be helped in the future.

[memphis02]

Thanks Robby! I'm planning a trip under there, this weekend with my best hydro guy (Father). The first time I checked into the problem several months ago, fluid was at an acceptable level nor was any found to be leaking.

I plan on giving bigfoot a call to discuss the issue with them; however all evidence points to an issue within the cylinder, in my non-expert opinion.

[tjbroussard]

Same thing occurs routinely on my 2014 37FS. I have found that the use of wheel chocks seems to help, thus seems related to shift of the coach as suggested. Still its always anyones guess if they will come up. As Robbie stated, the help desk tech at BigFoot is fantastic. Great customer support.

You are not alone....

[Robbbyr]

Another thing that the Tech from Bigfoot thought was a good idea, given the "Airliner creep", was the use of polyurethane jack pads. Since they allow for a slight amount of "slip" it seems logical they won't put as much of a lateral bind on the cylinders. I can't measure it scientifically, but it makes sense!

I use a poly pad from Bigfoot (not the leveler company!) that will outlast me. I built a divider box and mounted it in a basement compartment to contain them.

I'm thinking whatever I can do to help the cylinders live can't hurt!