Sailing Sea Dream of Clyde · video

What this video covers

Loss of vacuum pressure and backflow from the holding tank into the toilet bowl indicate a failing Jabsco Y-valve on a Lavac marine head.0:02 On a Westerly Discus, the vacuum-flush system relies on airtight seals to function; worn gaskets and significant calcium buildup—caused by the reaction between seawater and ammonia—often compromise these seals.0:21 To service the valve, first close the through-hull fitting to prevent flooding.0:55 Remove the valve from the bulkhead using a 7/16-inch socket to undo the mounting bolts.2:41 Disassemble the unit to access the internal gaskets and ports.2:38 Use vinegar to dissolve rock-hard calcium deposits from the valve housing.4:37 Replace all internal gaskets, applying marine-grade grease to the new seals and openings before reassembly.5:49 Ensure all screws are snug but not overtightened to avoid damaging the plastic housing.6:37 Proper maintenance of these seals restores the vacuum necessary for the Lavac head to flush effectively and prevents waste from returning to the bowl.7:06

Boats in this video

More from Sailing Sea Dream of Clyde

How To Replace Rigging & Emergency OFFSHORE RepairsMay 2026Sailing Into The Wilds Of Alaska - Starting The Inside Passage With A BANG! - Ep. 108May 202624 Days Across The Pacific: From Tropics to GlaciersFeb 2026This Is What Sailing Hawaii Actually Looks Like | Hilo to HonoluluFeb 2026

From Sailing Sea Dream of Clyde — see the channel’s boat, crew, and every analyzed video.

The Sailing Directory Newsletter

One email with the fleet's best finds — the moments, boats, and stories worth your watch time. Enter your own address to get your own copy.