How to Replace a Flat Cap on HydraPak Bottles

Quick answer

To replace a flat cap on a HydraPak bottle, first identify the correct cap size (42mm or 63mm), remove the old cap, then thread the new cap on hand-tight. This guide covers both sizes.

Step-by-step replacement guide

1. Identify the cap size: Check the bottle's opening diameter. Use a ruler to measure the inner diameter of the opening: 42mm or 63mm. Alternatively, refer to the bottle's product page or original packaging. Common mistake: ordering the wrong size. Double-check before purchasing.
2. Remove the old cap: Unscrew the old flat cap counterclockwise. If it is stuck, rinse the bottle with warm water to loosen debris. Do not use tools that could damage the cap or bottle threads. Checkpoint: Inspect the bottle threads for cracks or damage before installing the new cap.
3. Install the new cap: Place the new flat cap on the bottle opening and turn clockwise until it is snug. Tighten only by hand. Over-tightening can strip the threads or crack the cap. Common mistake: over-tightening. Hand-tight is sufficient for a leak-free seal.
4. Test the seal: Fill the bottle with water, close the cap, and turn the bottle upside down over a sink. Check for drips. If it leaks, remove the cap and reinstall it, ensuring the threads are aligned. Checkpoint: A small drip indicates the cap is not seated correctly. Re-thread and try again.

Flat cap options

• Flat Cap - 42mm: This 42mm flat cap is a replacement for the Stash 750ml bottle and Seeker 2L, 3L, 4L, and 6L containers. It does not fit SoftFlasks or the Seeker 10L. Ensures you select the right cap for your bottle to avoid leaks and compatibility issues.

  

• Flat Cap - 63mm: This 63mm flat cap fits all HydraPak products with a 63mm opening, including the Stash 1L bottle and Expedition water storage container. Provides a secure seal for larger bottles and containers, keeping your water clean and leak-free.