Tecreddy RV Toilet Seal Replacement for Dometic 300/310/320 2-Pack — OEM 385311658 Rubber Gasket, 4" OD/2.75" ID

Tecreddy RV toilet seal replacement is a two-piece rubber gasket kit designed to restore a reliable flush and stop leaks in Dometic 300, 310, 320, 400, 410 and 420 series toilets.

If your RV toilet leaks, won’t hold water, or has a worn flush ball seal, replacing the gasket is often the fastest, least expensive solution. This Tecreddy kit contains two factory-molded rubber seals sized to match the OEM part number 385311658. The seals are engineered to fit the listed Dometic models and are intended to be a direct, long-lasting replacement so you can avoid full toilet replacement or costly service calls.

How do I know this gasket fits my Dometic RV toilet?

These seals are made to replace part number 385311658 and are compatible with Dometic models 300, 310, 320, 400, 410, and 420. They do not fit model 210, 510 or other unlisted models, so verifying your toilet model or the OEM part number is recommended before purchase.

• Fits Dometic 300/310/320/400/410/420 series
• Replaces part number 385311658 exactly
• Not compatible with 210, 510, or other unlisted models
• Measure outer diameter 4" and inner diameter 2.75" to confirm

What makes these seals durable and leak-resistant?

The Tecreddy seals are pressed from special-grade rubber using original-device molds to match original contours and ensure an accurate seating surface. The material resists compression set so the gasket retains shape through repeated use, improving reliability compared with brittle or poorly formed replacements.

• Special rubber compound for longer service life
• Factory tooling reproduces OEM geometry for proper sealing
• Designed to resist flattening and maintain a water-tight seal
• Sold as a two-piece kit so you have a spare on hand

Is installation difficult — do I need tools or a plumber?

Installation is straightforward and typically requires no tools or toilet disassembly. The worn gasket can be popped out and the new seal seated by hand; install the marked side facing up to ensure correct orientation. Most users can complete the swap in minutes without specialized skills.

• No toilet removal or plumbing work usually required
• Push out the old seal and press the new one fully into place
• Observe the marked side up orientation before seating
• Keep the spare gasket for future maintenance

What dimensions and pack size are included?

The gasket measures 4.0 inches outer diameter with a 2.75 inch inner diameter, matching the specs of the original Dometic seal. This listing supplies two identical seals so you can repair two toilets, keep a backup, or replace a second worn part later without another order.

• Outer diameter: 4.00 inches
• Inner diameter: 2.75 inches
• Pack quantity: 2 seals
• Marked side indicates correct installation orientation

Who is this for? The Tecreddy RV toilet seal replacement kit is ideal for RV owners, fleet maintenance teams, and DIY enthusiasts who want a cost-effective way to stop leaks and restore flush performance on compatible Dometic toilets. If you want a direct-fit, factory-molded replacement without replacing the entire toilet or scheduling professional service, this two-pack provides the parts and dimensions you need to get back on the road with confidence.