I had the same problem with the GMC that I bought last year. The first
problem was that the dump valve had been moved from the tank to the end of
the hard drain line at the end of the coach. The coach had sat with a semi
full tank for a long time. When I opened the drain valve, a trickle of
liquid came out. Looked down the tank and it was fairly full.
Parked the coach so the end of the valve opening was over a dump station
catch basin and routed out the plugged pipe. Messy sludge. Seems that the
previous owner used a lot of toilet paper and the residual sludge filled
the line and most of the tank. Once the drain line was cleared, I connected
the drain hose to the dump station hole. I then went in from the toilet
with a wand and flushed out the tank. That took quite a bit of time because
the paper had filled a lot of the holding tank. The problem is that the GMC
tank is shallow and a big wad of toilet paper can have a tendency to just
build up beneath the toilet. This is especially true if the tank does not
have much liquid in it. Traveling with the grandsons recreated the problem
and had to use the wand a couple of times.
Changed the valve location next to the tank. Also added a RV quickie flush
and hosed it to a quick disconnect high up in the wheel well. When at a
site and connected to a drain, I dump and follow with a flush to make sure
the tank is dumped. Then add a gallon for sloshing the AquaChem treatment.
We have travel the last 9,000 miles with no problems. Even the level
indicators work after a water flush.
Chuck Botts, San Diego, Ca. The spring flowers and trees are blooming and
the transient humming birds are joining the locals in feeding off the
feeders in the back yard. I guess our "winter" is nearly over here in
Southern California.
problem was that the dump valve had been moved from the tank to the end of
the hard drain line at the end of the coach. The coach had sat with a semi
full tank for a long time. When I opened the drain valve, a trickle of
liquid came out. Looked down the tank and it was fairly full.
Parked the coach so the end of the valve opening was over a dump station
catch basin and routed out the plugged pipe. Messy sludge. Seems that the
previous owner used a lot of toilet paper and the residual sludge filled
the line and most of the tank. Once the drain line was cleared, I connected
the drain hose to the dump station hole. I then went in from the toilet
with a wand and flushed out the tank. That took quite a bit of time because
the paper had filled a lot of the holding tank. The problem is that the GMC
tank is shallow and a big wad of toilet paper can have a tendency to just
build up beneath the toilet. This is especially true if the tank does not
have much liquid in it. Traveling with the grandsons recreated the problem
and had to use the wand a couple of times.
Changed the valve location next to the tank. Also added a RV quickie flush
and hosed it to a quick disconnect high up in the wheel well. When at a
site and connected to a drain, I dump and follow with a flush to make sure
the tank is dumped. Then add a gallon for sloshing the AquaChem treatment.
We have travel the last 9,000 miles with no problems. Even the level
indicators work after a water flush.
Chuck Botts, San Diego, Ca. The spring flowers and trees are blooming and
the transient humming birds are joining the locals in feeding off the
feeders in the back yard. I guess our "winter" is nearly over here in
Southern California.
