holding tank guages

Discussion in 'General RVing' started by Calgary Dave, Jul 21, 2008.

  1. Calgary Dave

    Calgary Dave Member

    I just finished borrowing a friends motorhome and after emptying both (black and grey) tanks the one guage still said 3/4 full. I shrugged this off as an old motorhome with a faulty guage.

    This weekend I've just purchased a TT that was meticulously taken care of. But this one too, says the black tank is 3/4 full even though the seller said it's been winterized. The grey tank, at first, indicated 1/4 full...after running the water lines to get rid of antifreeze it now says 1/2 full. But I doubt I even ran a gallon or two tops. At this rate it'll be full in another 15 minutes! (I haven't tried to drain the holding tanks yet, as I assumed they were both empty, as per winterizing. It's still in our driveway as I check everything out)

    Do holding tank guages normally tend to "go"....is there a way I can fix it? or at least know if its working properly?
  2. utmtman

    utmtman Senior Member

    Re: holding tank guages

    Two things to cause this one is dirty tanks even with a new rig. One needs to put some borax soap, dawn dishwashing detergent, and bleach down with half 1/3 to 1/2 tank of water and move the rig around to clean the gages. Than drain. Second is bad gage but that usually is when no matter what you do you get no changes on the gages.
  3. krautdog

    krautdog Member

    RE: holding tank guages

    The gauges on my 99 Mallard are kind of screwy too, I usually just take a peek into the toilet when I flush, the black water tank is translucent so, it's pretty easy to see how full it is. When it gets close to the top, I dump it.

  4. C Nash

    C Nash Senior Member

    Re: holding tank guages

    Most of those guages are troublesome but I have found that using plenty of water and rinsing good is the best cure to keep them working.
  5. Guest

    Guest Guest

    Re: holding tank guages

    I agree with Nash ,, and btw all holding tank sensors are NOT even 99% correct u have to test them for u'r self ,, by this i mean see how really full is full on the sensors ,, but it's an rv learning thing that all of us have come to take for granted over time ;) :approve: :approve: :approve: :approve:
  6. onthecoach

    onthecoach Senior Member

    Re: holding tank guages

    I have been told over and over that the gauges on MH are useless....however, my experience has shown that they are really quite accurate. I've had 2 MH's and the one thing that has ALWAYS worked well in both have been the tank guages. Thank God for small favors!!! :)

Share This Page