Limit switches on Quadra/Bigfoot Hydraulic Levelling Systems

Let me start by saying the Bigfoot hydraulic leveling system is one of the best out there.  Powered extend and retract, and in the case of the system I have, automatic levelling and separate pumps for each jack.

When I bought my rig, used, the control panel always showed all jacks were up.  Everything worked fine, except automatic retract, and I wouldn’t get an audible alarm if I turned the key with the jacks down.  A little bit of troubleshooting pinpointed the limit switches as the problem.  It was obvious that they were rusted and not making contact.  When passing through Bigfoot’s neck of the woods, just inside Michigan north of Middlebury, IN, I stopped in to see about buying new switches.  Evidently, they’re not that expensive, and probably fail with some regularity–they sent a guy out to meet me in the parking lot with a bag with four new switches and the splice connectors to install them.

Standard limit switch on Bigfoot jack.
Standard limit switch on Bigfoot jack.

It looked pretty simple.  The switches threaded into a fitting welded to the side of the hydraulic cylinder, and I’d have to cut and splice the two switch wires back into the harness.  The front two switches turned out to be about that simple–a little bit of wrestling getting them loose, but overall not too bad.

The back was a different story.  They’re right behind the rear axle, and had been sprayed with all manner of road debris, salt, rain, etc., for over 200,000 miles.  They were in tight.  The fitting that holds them in sits very close to the cylinder, and the switch itself is such that you can’t get a deep-well socket onto the nut.  Essentially, the only two options left were a closed-end wrench, which was too thick to fit between the nut and the cylinder, and an open-ended box wrench.

DSCN1352
New limit switch installed with hose clamp.

The box wrench would show that it wasn’t going to be strong enough to turn the nut.  We’d tried all the tricks to loosen the rust on the threads.  What now?  Well, the existing switch was going to be trash anyways, so we cut the plastic upper part off, leaving just the metal nut.  That allowed a socket to fit on.  Home free, right?  Not so fast–the socket got us a good grip, enough to twist the nut free of the threaded portion, still solidly held in place.

Time for plan B.  Leave the unsealed switch behind for one that’s meant to be in a nasty environment.  Here’s what I ended up with:

It’s an ME-8169 Flexible Coil Spring Arm Limit Switch, available for less than $5.  As cheap as it is, and not coming from a name brand, I wasn’t expecting much.  It was mounted with a hose clamp around the hydraulic cylinder, and the springy actuator meant that we didn’t have to get carried away with how accurately it was mounted–going beyond where the switch actuated just meant that the actuator flexed, instead of breaking the switch.

That took care of one of the other problems with the original switch.  Inevitably, especially when parked in mud or gravel, stuff would end up on the jack pads.  If it was stiff enough, it would actuate the switch early, and would either crush the switch internally or bend (and jam) the actuator pin.  This was less of a problem with the upgraded jack feet (that’s another post), but far from ideal.

After almost 2 years, both switches still work reliably.  The front ones work too, so the factory style may be good enough if you can get the old ones out.  But even at a fraction of the price of a real, name-brand industrial limit switch, the flexible actuator switch is a step up from the factory design.

 

 

4 Comments Add yours

  1. Ryan Blair says:

    I have a 2002 Master ???? by Georgie Boy. Second Owner with 30057 miles on it. I believe what your last post was on Actuators or jack pads, may be my issues.

    Over the 4th of July went camping, my right side front would not go down. End up putting 1 2×8 in rear and 2 2×8 boards in front tire, drove forward until I was level. Shut off rig was 100% level, extended both slides.

    As I continued to read I discovered that the pistons on my Motorhome will only extend out 11 1/4 inches total. Piston is a total of 17 inches externally. I was well over 11 1/4 inches not allowing my piston to extend outward.

    Further reading Bigfoot Original design states that if when pushing manual buttons if flat jack stand does not get a reading it will not allow piston to extend outward?

    Makes sense now but did not at the time of setup.

    Thank you.

    Please note: When you are driving and you notice your all up light goes off, alarm starts what I did to stop it?

    Went to Hardware store bought 4 rubber boots that fit alarm pins, installed a boot on each pin. Allowing all up light to stay on.

    1. Dave says:

      Hi Ryan,

      I’m not sure which Bigfoot system you have, but mine at least is not aware of what the individual jacks are actually doing. There are timeouts in the auto-leveling process where it will stop if there’s no movement (as in fully extended jacks or jacks that aren’t working), but it doesn’t know anything about the jack’s position. I’ve not run across a situation where the control panel wouldn’t enable a jack’s operation in manual mode.

      As far as the alarm, I did have a switch where one of the actuators rusted through causing the alarm to go off. I just unplugged the control panel while traveling until I was able to fix it. Note that when the actuator fails (i.e. the switch contacts are closed), automatic leveling won’t work as it fully retracts all of the jacks before starting.

  2. Carl Barrier says:

    (don’t cha hate it when you drop phone and loose all that typing) I’m so glad to find this info on the Bigfoot switches. I had not thought these types of limit switches could be uses. I had tried the rubber tip. I tried the Bigfoot trouble shooting guide. When retracting the cylinder would drop back down about 1/4″ and cause the red light and alarm to come on. According to Bigfoot, the hydraulic pump needs replacing because internal checks valves stopped working. I found these comments when looking for a used pump.

    Having worked as the Millwright for 18 years at a saw mill, I’m very familiar with these types of “limit switches” made by Cutler Hammer and Allen Bradly. One switch body could be configured to do unlimited number of things, I.e. roller tip, spring tip, stiff adjustable wire, etc. And the contacts could be wired as single post single throw, double post, double throw, so on and so forth.

    Wish I had my hands on one this Sat. morning. I’ve been in Critical Patients at hospital for past week and supposed to be on bed rest at home, but would climb under RV and rig up a spring switch right now.

    If it wasn’t for bad luck I’d have no luck at all. Couple months ago when leveling RV for slide out, heard and felt a big jolt. Got out and looked under chasis is to see what happened? Didn’t see any thing wrong. Later went to get gas. Heard scraping sound. And again looked. Didn’t see anything. Back at home, parking RV in my pea gravel driveway, backing up felt as if rear tires stopped, got out and still did not see anything, couple of times, and then saw it!!!

    Looking back(ass)wards, the original big bang was the wielded bracket broke loose and the whole Bigfoot assembly jammed up and stuck into the subfloor, out of sight. The scrapping was the assembly being dragged along by the battery cables. It was out of sight behind the back tires. In the pea gravel driveway, the RV not being able to move was the assembly getting jammed into the tires. Trying to move, back & forth, making large pits and scrapings in gravel, lead me to look behind the tires. And, all the above lead me to buying a whole new assembly from Quadra.

    Still makes me wonder if there are uses parts out there in the RV World. Sorry for the dierhear of the mouth. What else is there to do when on (wife enforced) bed rest.

    1. Dave says:

      Glad you found it useful! Best wishes for a speedy recovery!

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