Description
385311658 Flush Ball Ring Seal — Complete Dometic Bowl Seal Kit
Slow bowl water loss or faint sewage odor in your RV bathroom almost always points to a worn flush ball seal ring. The iFJF 385311658 is an exact-replacement seal for the critical junction between the flush ball and toilet bowl in Dometic 300, 310, and 320 series gravity-flush toilets. Made from durable, chemical-resistant polymer, this seal restores the water-tight and odor-proof barrier in under 30 minutes — no tools required, installed entirely from above the bowl.
Key Features
-
Exact OEM Fit: Precision-molded to Dometic specifications for 300, 310, and 320 series toilets — drops into the seal groove without modification or trimming.
-
Dual-Seal Function: Creates a positive water barrier to keep bowl water from draining into the holding tank AND an odor seal to prevent sewage gases from entering the bathroom.
-
Chemical-Resistant Polymer: Engineered to withstand formaldehyde-based and enzyme-based holding tank treatments — won't swell, soften, or degrade.
-
Tool-Free Installation: The only Dometic toilet repair that requires zero tools — accessed and replaced entirely from above the bowl in 20-30 minutes.
-
Budget-Friendly Maintenance: The most affordable Dometic toilet seal on the market — replace prophylactically every 2 years for peace of mind.
Compatibility
| Brand |
Series |
Toilet Type |
| Dometic |
300, 310, 320 |
Gravity-Flush (All Models) |
Specifications
| Spec |
Value |
| Part Number |
385311658 |
| Material |
Chemical-Resistant Polymer |
| Seal Type |
Flush Ball Ring / Bowl Seal |
| Installation |
Tool-Free — Above Bowl Access |
| Includes |
Seal Ring + Installation Grease |
Symptoms of a Failed Bowl Seal
- Bowl water drains completely within 1-2 hours of flushing
- Holding tank odor noticeable near toilet (especially on hot days)
- Mineral buildup or black residue visible around flush ball opening
- Toilet requires multiple flushes to clear waste (insufficient bowl water)
- Gurgling sounds from toilet when not in use
Installation Guide (Tool-Free!)
- Turn off water supply to toilet. Flush and hold pedal to drain bowl completely.
- Step on flush pedal and hold open to expose the seal ring in the bowl opening.
- Use fingers or a plastic pry tool to lift the old seal ring out through the bowl — it sits in a groove around the opening.
- Clean the seal groove thoroughly with a rag — remove all mineral deposits and old grease.
- Apply a thin coat of included silicone grease to the new seal ring.
- Press the new seal firmly into the groove. Ensure it's fully seated all the way around.
- Release pedal, turn water on, fill bowl, and check for water retention.
Frequently Asked Questions
Q: My bowl is dry every morning — is this the fix?
A: Yes, this is the classic symptom of a failed flush ball seal. The seal can no longer hold water in the bowl, so it slowly drains into the holding tank overnight. Replace the seal ring to restore water retention.
Q: Do I need to remove the toilet from the floor?
A: No. Unlike many RV toilet repairs, the flush ball seal is installed entirely from above the bowl. Simply hold the pedal open and access the seal groove through the bowl opening. No dismounting required.
Q: How often should the flush ball seal be replaced?
A: Replace every 2-3 years under normal use, or at the first sign of bowl water loss. If you full-time RV or use harsh holding tank chemicals, inspect annually. The seal is inexpensive — proactive replacement prevents odor problems.
Q: Will this stop the holding tank odor in my bathroom?
A: Yes, if the odor is coming through the toilet bowl. A worn seal allows tank gases to bypass the flush ball. Combined with good tank vent maintenance, a new seal eliminates bathroom odors.
Q: Why does my seal keep failing quickly?
A: Frequent seal failures usually indicate mineral buildup from hard water or abrasive chemical treatments. Use a water softener if you have hard water, and consider enzyme-based tank treatments instead of formaldehyde-based products.
Q: Is this genuine Dometic or aftermarket?
A: This is a high-quality aftermarket replacement manufactured to Dometic OEM specifications. It matches the exact dimensions and material properties of the factory seal at a significantly lower cost.
Related Products
