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Topic: Audit monitor reading conundrum (Read 662 times) previous topic - next topic

Audit monitor reading conundrum

When we first took ownership of our 1994 U240 GV I was noticing inconsistent tank readings ( black & gray ) so, as many on the forum have suggested previously, I used the dawn / calgon  formula on many outings and managed to get both tank sensors behaving again. The last couple of trips I am finding that the monitor is showing that the tanks are needing to be emptied, although we could not possibly have filled both tanks that fast, every 2 days, both tanks. Is this a sign that the sensors are finally breaking down or is there another reason, sensor adjustment on the audit?
Geoff & Pat Haygarth
1994 U240 SBI GV 36ft Cat 3116, Allison 6 speed
 Build #4448
2015 Jeep Wrangler Sport

Re: Audit monitor reading conundrum

Reply #1 –
Geoff,

Chasing "clean gray and black tank sensors" can drive you crazy.  Only long-term solution is to go with the more modern external tank sensors.

But, If you fill your potable water tank and live off that, you will never run out of gray or black tank space before needing to refill the potable tank.  That is what many of us do.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Audit monitor reading conundrum

Reply #2 –
Quote from: wolfe10 –
Chasing "clean gray and black tank sensors" can drive you crazy.  But, If you fill your potable water tank and live off that, you will never run out of gray or black tank space before needing to refill the potable tank.  That is what many of us do.

What Brett said, in spades!  We've had sensor lags on all three of our coaches, as long as the potable, VDC, back-up camera and propane sensors work, I can live with it.  ^.^d
1993 U-240 "La Villa Grande"..CAT 3116 w/ Pacbrake PRXB...Allison 3060 6-speed..
Previous: 1983 Airstream 310 turbo diesel, 1979 Airstream 280 turbo diesel
                                      Build # 4297
                                      PNW natives
                      Home base:  'Cactus Hug' (Ajo, Arizona)
                        DW Judy & Chet the wonder dog
                        Full-Timers 'Sailing the asphalt sea'

Re: Audit monitor reading conundrum

Reply #3 –
I find when bouncing down the road, the tank levels are all over the place.  I attribute that to "stuff" splashing around in the tanks, and "wetting" the sensors above the actual level.  I always take my tank readings first thing in the morning, before moving the coach.  I figure after the tanks have all night to settle down, I will get as close to a correct level as is possible with 23 year old technology.
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Audit monitor reading conundrum

Reply #4 –
As usual great feedback and advice, thank you all.
 We are returning home tomorrow for 7 to 8 days and then we are back out for a few weeks, so, I will do as Brett advises and run off the potable system.
 I am also contemplating the new outside sensor system but am unsure how I access the tank walls on our 1994 u240 GV so the tapes can be applied.
Geoff & Pat Haygarth
1994 U240 SBI GV 36ft Cat 3116, Allison 6 speed
 Build #4448
2015 Jeep Wrangler Sport

Re: Audit monitor reading conundrum

Reply #5 –
It's really not a big deal, we don't use anything but our body fluids in the black tank, no t.p: once cleaned, one mite be back in business. Grey tank (I'm the dishwasher) debris is held in the sink strainer and deposited elsewhere.  I break all the rules when at full hook-up: both dump valves are left open.  We  take care of our "business" first, then do dishes, which gives the lines a "flush".  Problems zero.  ^.^d
1993 U-240 "La Villa Grande"..CAT 3116 w/ Pacbrake PRXB...Allison 3060 6-speed..
Previous: 1983 Airstream 310 turbo diesel, 1979 Airstream 280 turbo diesel
                                      Build # 4297
                                      PNW natives
                      Home base:  'Cactus Hug' (Ajo, Arizona)
                        DW Judy & Chet the wonder dog
                        Full-Timers 'Sailing the asphalt sea'

Re: Audit monitor reading conundrum

Reply #6 –
Thanks Mike.
 Has anyone gone through the process of installing the new style tank level sensors on my year of GV?
Geoff & Pat Haygarth
1994 U240 SBI GV 36ft Cat 3116, Allison 6 speed
 Build #4448
2015 Jeep Wrangler Sport

Re: Audit monitor reading conundrum

Reply #7 –
Geoff,
I did not replace mine with the external sensors. I went with these: http://www.rvprobes.com/buyprobes.html . Not much difference. Black water tank showed full all the time w/ the old system and the new ones show full only half the time. Never correct unless I am sure it is close to full and I don't need gauges to tell me that.
'91 U240 GV / 36'
CAT 3208 w/Allison MT 643  4 speed
'10 Ford Flex

Growing old is mandatory
Growing up is optional

Re: Audit monitor reading conundrum

Reply #8 –
Hi Jerry,
 Thanks for responding, was it difficult to access the tank walls?
Geoff
Geoff & Pat Haygarth
1994 U240 SBI GV 36ft Cat 3116, Allison 6 speed
 Build #4448
2015 Jeep Wrangler Sport

Re: Audit monitor reading conundrum

Reply #9 –
Geoff,

Have you "explored" both ends of your wet bay?  On our '93 U280 the tanks are semi-accessible from both ends.  I realize your U240 may be different, but the means of access is probably similar.

On our coach, to access the tanks on the driver side, I would have to remove two sets of panels.  One set covers the hose and electric cord reels, and the other is the one that provides mounting for the outside faucet, and covers the dump valves.  The first 3 photos below show those two bays with the panels removed.  You will notice that all 3 tanks are "sloped" on this end...the tanks are "longer" at the top than at the bottom.

On the curb side of the coach, the fresh water tank is visible when I look into the water pump/water heater bay.  The black and gray tanks are behind a panel (in the adjacent bay) covered in gray "wooly" material.  You can see in the photo where the "washout" hoses attach to the tanks.  I have never removed this panel, but I can see the top edge of both tanks, so I know they would both be totally accessible at this end, by removing the cover panel.  In the photos, on the water tank, you can see some of the original sensors for the Audit tank level system.  Mine still work just fine, so I have never messed with them.

The good thing about the curb-side end of the holding tanks is that they are flat and vertical.  It would be much easier to affix the external sensor strips (SeeLeveL) to this end of the tanks.  The only bad thing (at least on my coach) is that the top half of the fresh water tank is kinda hidden up behind the water heater.  I can, however, see and reach the top of the tank by doing a little bit of creative bending and stretching.

You will just have to remove all the panels covering both ends of your holding tanks, and see what it looks like behind them.  It's no big deal - just a bunch of screws and perhaps some caulking compound holding everything together.  Once you do that, you can decide which sensor system will work best for you.
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Audit monitor reading conundrum

Reply #10 –
Thanks Chuck,
 I will be going to the RV this weekend, I can tell by your photos ( thank you ) that ours is a lot different to yours in layout. But the plan is to remove a panel or two and see what I can.
Geoff
Geoff & Pat Haygarth
1994 U240 SBI GV 36ft Cat 3116, Allison 6 speed
 Build #4448
2015 Jeep Wrangler Sport