A bathtub drain that won’t stay open is typically caused by mechanical issues in the trip lever assembly, spring mechanism, or corroded linkage. The problem often stems from a worn-out spring, misaligned linkage, or buildup of grime preventing the lever from locking in the open position. Most solutions involve disassembling the overflow plate, inspecting the internal components, and either cleaning, adjusting, or replacing damaged parts.

Key findings from the sources:

• Spring mechanism failure is a common cause, requiring inspection or replacement ^[6]
• Corroded or misaligned linkage can prevent the lever from staying down, often fixed by cleaning and lubricating ^[3][7]
• DIY repair kits (costing ~$16) can replace broken levers without professional help ^[1]
• Adjusting the threaded linkage may resolve improper sealing or drainage issues ^[4]

Step-by-Step Solutions for a Bathtub Drain That Won’t Stay Open

Inspecting and Repairing the Spring and Linkage Mechanism

The trip lever system relies on a spring-loaded mechanism to hold the drain open or closed. When the lever won’t stay down, the spring is often worn out, or the linkage is obstructed. Start by removing the overflow plate to access the internal components.

• Remove the overflow plate: Unscrew the two bolts securing the plate with a screwdriver. This exposes the lever, spring, and linkage ^[6].
• Check the spring: The spring should provide tension to keep the lever in place. If it’s stretched, rusted, or broken, it must be replaced. A functional spring will resist movement when pulled ^[3].
• Inspect the linkage: Look for corrosion or misalignment in the metal rod connecting the lever to the plunger. Clean any buildup with a wire brush and apply plumber’s grease to ensure smooth movement ^[7].
• Test the mechanism: After cleaning, manually move the lever to verify it stays in both the up (closed) and down (open) positions. If it still fails, the spring or linkage may need replacement ^[4].

In many cases, simply lubricating the parts and realigning the linkage resolves the issue without requiring new components. However, if the spring is damaged, replacement parts are inexpensive and widely available at hardware stores.

Adjusting or Replacing the Plunger and Trip Lever Assembly

If the spring and linkage appear functional but the drain still won’t stay open, the plunger itself may be misaligned or worn. The plunger is the rubber or metal component that seals the drain when engaged. Over time, it can become caked with soap scum or lose its seal.

• Access the plunger: After removing the overflow plate, pull out the linkage to expose the plunger. Use a flexible retriever tool if the plunger is stuck in the drain pipe ^[4].
• Clean or replace the plunger: Remove debris from the plunger and the drain hole. If the rubber is cracked or deformed, replace it with a universal plunger kit (~$10–$20) ^[1].
• Adjust the linkage length: The threaded rod connecting the lever to the plunger may need shortening or lengthening. Turn the adjustment nut to modify the tension, ensuring the plunger fully retracts when the lever is down ^[7].
• Reassemble and test: Reattach the linkage, ensuring the plunger moves freely. Test the lever multiple times to confirm it holds in both positions. If the issue persists, the entire trip lever assembly may need replacement ^[10].

For severe corrosion or damage, a full replacement kit (including lever, spring, and plunger) is often the most cost-effective solution. Videos like The Handyman’s guide demonstrate how to install these kits in under 15 minutes, saving up to $250 in plumber fees ^[10].