What replacement plunger do I need for a YHS (standard) series Boshart yard hydrant?

The YHS series repair kit has two plungers with slightly different diameters due to a slight change to the valve bodies back in 2011.

When the plunger is removed for replacement, simply select and install the plunger that matches the one you removed. They are easily identified. Older models, prior to early 2011, have a brass threaded core that does not extend to the top edge of the rubber. On the newer models, manufactured in late 2011, have a brass threaded core which is flush with the top edge of the rubber.

Regardless of the date of manufacture, the kit will have exactly what you need. The inserted instructions card provides clear directions on which plunger to use.