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Old 07-20-2021, 08:01 PM   #1
Join Date: Sep 2010
Posts: 35
Question Black Tank Flush Nozzle Access

I have a Forester 2015 2861DS. The black tank flush is not working. Already verified that the anti-syphon valve is working and am now trying to see if there is access to the nozzle itself. I am thinking that it may be in the 4" x 4" box than runs across the side wall behind the toilet. The toilet supply line is inside this box.
Has anyone been inside that box?

Thanking you in advance!
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Old 07-20-2021, 08:35 PM   #2
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Join Date: Aug 2019
Posts: 1,062
takes good water pressure .
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Old 07-21-2021, 10:13 PM   #3
Join Date: Sep 2010
Posts: 35
Thomas ho,

Thanks for the reply!

I always use the flush at the same place with the same pressure however now I have a plugged jet and have not yet figured out where I can get to it to clean it out.
If it means dropping a tank, then I won't be doing that!

The way the tank is mounted, inside a compartment, I can see the front with the tank level sensors, the right side is against the grey tank and the left side is against the side wall of the compartment. That only leaves the top or the back side.

I'll probably try filling the tank with water and some cleaner and then drive around for a while to see if it dislodges whatever is stuck in it!

Thanks again!
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Old 07-21-2021, 10:31 PM   #4
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Join Date: Jun 2021
Location: Central coast Calif.
Posts: 777
It seems like water pressure alone would clear the nozzle and driving around would have little effect. Try some air pressure from a compressor. If it is plugged that should do it.
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Old 07-22-2021, 08:12 PM   #5
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Join Date: Apr 2020
Posts: 3
Clean tank by dumping water down toilet. When clean fill tank with water until water is almost to top of piping at toilet. Hook a pump up to black tank flush hose and pump water backwards to pull water through flush valve.
Worked for me, I think sediment got into flush valve. I have since put a hose filter on black tank fitting to prevent sediment from plugging the valve.
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Old 08-26-2021, 09:31 PM   #6
Join Date: Sep 2010
Posts: 35
Smile Update

Thanks to all of the people that took the time to reply!

I still do not know the access location for the flushing nozzle(s) but I got lucky.

Completely filled tank while parked at home, added extra blank tank cleaner, waited 2 weeks, drove 50 miles to just outside the campground where we were spending 4 days and dumped at a rest area (free). Tried the flush valve and IT WORKED!!!

Lucky me!!

Thanks again to all!

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black, black tank, black tank flush, flush, tank

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