Liberty Fresh Water Gauge

[tdelorme]

I let my fresh water tank run completely empty on a trip a couple of weeks ago. No big deal as we were pulling in at home when it happened and when I parked I flipped the water pump breaker.
Now, the next day after we unloaded the coach and I backed her into the bus barn, I hooked up the hose and started filling the fresh water tank and dumping the waste tank. Standard stuff. The waste tank is always fast and the fresh water takes another ten minuets or so and I watch the gauge so that I don't overfill and spill a bunch of water on the barn floor. This time, the gauge doesn't register the water going into the tank. The gauge just keeps flashing the red empty light even though the tank is in the process of being filled. When the tank is full and a little water starts to spill out of the overflow, I shut the fill valve, unhook the hose and turn the gauges off.
I don't give it much thought, believing that when I turn the gauges back on all will return to normal. No such luck, even with the fresh tank full, the gauge empty lights are still blinking and the levels shows zero.
Any thoughts appreciated. I can call Liberty tomorrow, but I've got some time today to work on the problem and would like to get it fixed.

[Alek&Lucia]

Ted,

Locate your Fluid Level Sensor SYM and try to reset it by pushing the little button on the bottom,

Alek

[Jon Wehrenberg]

On top of the fresh water tank is the black box for the level sensor. On the box is a very tiny button which if pressed kicks on a small internal compressor that blows air into the sensor level tube. The box should be velcroed onto the top of the fresh water tank and you should be able to get your hands on it by opening the door and finding it on the top of the tank above the fittings going to the water pump.

Manually press that button and let the thing cycle. You should hear a fairly quiet buzz to indicate the compressor is working. It should shut off after a minute or so. This is the noise you should periodically hear when the bus is in a quiet place. If there is no change in indication there is a procedure for re-calibrating the level sensor. One thing that will screw up the level readings is if the tube going into the back of the black box is leaking at the connection. The way it works is by blowing air in the tube and then the head pressure on the tube is read by the box and translated into a small light. If the tubing connection leaks water rises in the tubing and the internal tubing pressure is ambient which is read as an empty tank.

[sawdust_128]

Once these sensors start to go, they continue to get worse. Sometimes very quickly. Alek can verify that as he watched and helped me with one this summer.

Also, Alek is the expert on these. He gave me quite an education on them, helped me get the order completed at a good price and then made sure it was installed correctly. Yep he pushed me and my dammit tools right out of the way. Thank you Alek and just so you know, it still works great.

If I remember correctly, the newer modules can be repaired. I now have all newer modules installed in my coach. You guessed it, the one that failed this summer was an older version.

[tdelorme]

Well thanks for the help, but nothing has worked so far. Alek, the little reset opening is so small it's hard to tell if there is a button in there or not. Tried all three locations of the level indicators, but still reading zero.
Jon, the black box was right were you described and the pump runs when the button is pushed, but no positive effect. There is no leak anywhere around the tubing running into the box. If fact, there is no water in the tube, just air.

[sawdust_128]

Ted, there's just not much else to do. It sounds like the sensor has made the journey.

[Jon Wehrenberg]

Ted,

Swap it out with the holding tank box. But make sure they are interchangeable. In the interest of good sanitation I would suggest you not swap tubes.

If the holding tank box works you know the problem is in the black box.

[Alek&Lucia]

Ted,

You said that you hear the buzzing sound. That is good, but maybe the air pressure is low.(bad SYM Sensor or plugged line)
Unhook the air tube and try to blow it with compressed air can ( dust remover for computers), also put few drops of bleach to it, and lets drain to the tank. Sometimes algae will form/grow and plug the tubes.

Here is some additional info:

http://www.headhunterinc.com/assets/...s%20series.pdf

Headhunter contacts:
Ph # (954) 581-6996 Toll Free: (800) 662-8557

Alek

[tdelorme]

Good idea, Jon, I will try that.
Alek, that link needs to be posted over on the "articles" page. That is just a ton of good information for troubleshooting these sensors.
Thanks for the help. I will update when I get her fixed.

[Jerry Winchester]

Here is the Liberty wiring schematic for those sensors.

acmeelec.jpg