Prior to a trip departure date, we work to check many of our systems. One such system is our Bigfoot Quadra Leveling system (Quadra = a pump for each leveler). This week, Jim noticed that one of the reservoir’s fluid (automatic transmission fluid - ATF) was cloudy. With a little research, we discovered that cloudy ATF means that the fluid has been polluted/invaded with water (I’m sure many if not most of you already knew this, we didn’t). Jim searched Quadra’s website for help. When none of the written troubleshooting documentation proved adequate, he emailed Quadra’s support folks and Clinton promptly responded with assistance.
Clinton explained: Water may get into the leveler’s reservoir by force if the vehicle is driven in wet conditions such as heavy rain or deep water puddles. It is important to make sure the tank cover is properly in place and in good condition (make sure there are no cracks and that the cover is not broken) to help prevent water and moisture from forcing its way into the tank. Moisture may also get into the tank from condensation from temperature changes.
He also provided instructions for replacing the ATF fluid in the fluid reservoir (tank) and cylinder. The tank is a 64 oz. reservoir (plan for replacement fluid and the disposal of waste fluid accordingly). As a side note, we are using Motorcraft MERCON LV ATF.
We studied Clinton’s instructions, researched double-acting cylinders (to understand how fluid moves in and out of the cylinder: see How Do Hydraulic Cylinders Work? - hydrauliconline.com (http://www.hydrauliconline.com/hydraulic-cylinders/how-do-hydraulic-cylinders-work/)), and revised the instructions so that they made sense to us. We will be using a transparent waste fluid jug for the final part of the draining procedure to visually verify that all of the milky pink fluid has been removed. The following is our modified procedure. Note that the procedure can be messy and we were advised to use eye protection, put cardboard or drop cloth under the work area, and anticipate sputtering/splashing of fluid as the pump empties the reservoir and begins to draw air.
Procedure for replacing fluid in tank and cylinder/jack.
- Before beginning the flushing procedure, fully extend all four pistons/jacks to ensure that all limit switches are functioning.
In manual mode, the limit switches seemed to be bypassed - Next, fully retract all pistons and visually confirm that all are fully retracted.
- Remove the hose from the top of the cylinder (the cylinder extend port) and place the hose end in a jug or drain pan of some sort.
- Using the system controller, run the pump in extend to pump all of the old fluid out of the tank. The piston will not move.
The pump pulls air before all of the fluid is expelled, leaving approximately 6 ounces in the bottom of the tank. - Now, add 4 to 6 ounces of new ATF fluid to the reservoir, and again use the controller to pump out the fluid. Check this drained fluid to verify that the it is clear (uncontaminated). Repeat this step as necessary.
We could not get all of the contaminated ATF out of the tank. After four flushes, we resorted to using a siphon to remove most of the contaminated fluid. We used a quart of fluid in this process. - Place the hose back on the top of the cylinder and tighten the fitting.
- Using a spout on the new ATF container(s), fill reservoir with new ATF to about 1” from the top.
This took most of two quarts. - Next, drain the old fluid from the bottom of the cylinder and its associated hose. From where the hose connects to the pump, remove the hose that goes to the bottom of the cylinder (That is, remove the hose from the retract port at the outside edge of the pump).
Beware! When the fitting was loosened, the pressure in the hose/system shot some fluid out. Maybe two ounces. Fortunately, most of it landed on the cardboard. - Place the hose end in a jug or drain pan.
- Before running the pump, you must place a finger over the empty fitting on the pump to prevent the pump from sucking air while it is pumping to extend the piston. Now you’re ready to run the pump in extend to extend the piston and force all the old fluid out of the retract side through the hose into the jug or drain pan. The piston will move!!!
Fully extend the piston to be sure to get all the old fluid out of the bottom part of the cylinder.
As a side note, we actually extended the levelers in pairs to avoid tweaking the RV frame. - It may be necessary to add fluid to the tank towards the end of the stroke of the cylinder to avoid running the tank fluid level too low.
We had to add fluid twice.
Note: Do not allow the amount of fluid in the tank to drop past 1½" depth. - Once the piston is fully extended, place the hose back onto the pump and tighten the fitting. Optionally, retract the piston slightly to add new fluid to the retract side of the cylinder, and repeat the flush. Reattach the hose and tighten the fitting.
We chose not to reattach the hose and manually retract the piston some. As expected, this left a bit of contaminated ATF in the retract side of the cylinder. - Now fully retract the piston.
- Once the piston is fully retracted, check the fluid level in the tank. The fluid level in the tank should be between ¾” and 1” from the top. Add or remove fluid as necessary.
We needed to add an additional quart of ATF. - Thoroughly clean the tank assembly (wipe down with a rag and use some brake parts cleaner) to remove grease and grime.
- Extend and retract all jacks a few times, keeping an eye on the tank assembly and checking for leaks (there shouldn’t be any significant leakage of ATF).
There was some noise on our first extension that we took to be caused by air in the line. - As per the user manual’s bleeding procedure, fully extend all four jacks and leave at full extension for 30 minutes. The weight of the motorhome will cause any air to be purged from the cylinder and hoses. After 30 minutes, retract all jacks.
We left the jacks fully extended for 40 minutes. It looks good.
Glad to have this task completed.
Now onto the fun stuff (well, after evaluating systems not yet checked).
Sue and Jim
Great post - love the details and pics!
One suggestion I have is to check the system at some point in the near future to verify there is no more water contamination. I have quite a bit of experience with water contamination of axles, transmissions, transfer cases, fuel tanks, and even engines. Hey, it's a Jeep thing :)
The one common fact is that it is quite rare that one system flush removes all the water contamination. Axles and fuel tanks seem to be the easiest while transmissions (manual), transfer cases and engines seem to be the absolute toughest. My guess is that your leveler system is somewhere in-between.
Thanks again and please keep us updated.
Thanks for the kind words and the suggestion Chet.
Jim checks all four leveler reservoirs a few times a year. I expect we will also be checking again while on our upcoming trip.
The one reservoir that had water contamination was for the right rear jack. It sits just behind the right duallys. We are guessing that some of the water that was thrown by those tires managed to evade the tank cover (it has a cutout near the top and is forward facing) and sneak into the weep hole in the reservoir cap. Jim fashioned a steel water shield and installed it between the leveler tank cover and the duallys. It’s hard to get an image to capture what he did… the photo below was the best I could do and should help illustrate Jim’s solution (understandably, he likes his approach better than wrapping the whole thing in plastic wrap… ok, my idea was not a permanent solution).
We expect to flush that leveler when we return from our trip in November.
We have been using our levelers for the last couple of weeks in temperatures ranging from 20 to 90 degrees. Other than having the limit switch stick on one leveler when the temperature was a rather cool 22 degrees, they have performed flawlessly. All of the reservoirs have remained free from contaminants. We still have not seen any rain or driven through water, so Jim’s water shield remains untested. Rain is in our forecast for early next week...
Sue