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Jtschnel · 05-17-2023, 08:44 PM

We have a 2022 Allegro Bus 45FP. The rear toilet is a macerator type. Occasionally the water has leaked out of the bowel but flushing several times has cured.

After our last trip the coach only sat for two weeks and I noticed the water had partially leaked out. I flushed it several times and now it drains within 10 seconds, can’t seem to get it to hold water. The coach is stored in a clean climate controlled building.

Any suggestions?

Old-Biscuit · 05-17-2023, 09:24 PM

2 possible causes

Pump discharge pipe is looped and top of loop needs to be higher than level in bowl
Vacuum breaker device on discharge pipe is not opening allowing water to siphon out

Jtschnel · 05-17-2023, 11:09 PM

Quote:

Originally Posted by Old-Biscuit

2 possible causes

Pump discharge pipe is looped and top of loop needs to be higher than level in bowl
Vacuum breaker device on discharge pipe is not opening allowing water to siphon out

Thank you for the information. I’ll look for an exploded diagram showing the location and what the parts look like.

Would both of those items be housed in the back side of the toilet? If so, they’ll be easy to access via the emergency door.

vettenuts · 05-20-2023, 06:57 AM

Mine leaks down, but not that fast. I do occasionally flush some Thetford RV Toilet Seal Lube & Conditioner through mine. It's made specifically for RV toilets. Have you tried manually purging the bowl (both buttons pressed simultaneously) and then doing a flush?

Just trying to think what you can try without removal or digging in too deep. A call to Tiffin might provide some insight as well.

alank · 05-20-2023, 09:07 AM

OldBiscut hit the points to check, but didn't give any detail. Take one, or both side covers off behind the stool where you'll see the top 180* elbow. This elbow may discharge water down a drain pipe in the wall or back down in the center of the stool base to a drain. That elbow is made of rubber and has previously been reported as not being properly tied up in some coaches, so it doesn't droop over to one side or the other and let water run out of the bowl. Some wire ties, etc. can correct that problem. The other item to inspect is the vacuum breaker located at the very top area of the elbow. If it's not opening up, that can draw water out of the bowl.

Jtschnel · 05-21-2023, 08:08 PM

Quote:

Originally Posted by alank

OldBiscut hit the points to check, but didn't give any detail. Take one, or both side covers off behind the stool where you'll see the top 180* elbow. This elbow may discharge water down a drain pipe in the wall or back down in the center of the stool base to a drain. That elbow is made of rubber and has previously been reported as not being properly tied up in some coaches, so it doesn't droop over to one side or the other and let water run out of the bowl. Some wire ties, etc. can correct that problem. The other item to inspect is the vacuum breaker located at the very top area of the elbow. If it's not opening up, that can draw water out of the bowl.

Thanks for the guidance. I’ll try to look at it tomorrow and report back.

keithnjulieb · 01-15-2025, 12:04 PM

On our 2019 Newmar Ventana 4369 the rear toilet started not holding water every now and then and then all of a sudden it was all the time. Our solution was the fact the Vacuum Breaker Valve was clogged and therefore not venting causing the water in the bowl to siphon back out.

The fix is to access the back of the toilet, which in our case was easy as the rear toilet back to the emergency door. Just opened the door and used a step stool to see the top of the valve (see photos). There you will notice a small silicone tip sticking up about even with the top of the valve and then 3 small vent holes inside around the tip. First pour a Very small amount of boiling water in the top of the valve. The water on ours drained out very slowly. Then take a qtip and clean around the area. Now I used a jeweler's very small phillips head screwdriver, could use a paperclip, and very lightly cleaned out inside each of the 3 holes. Cleaned with a qtip again. That solved out problem!!!