Quad Seal Stem replacement on Flomatic 424 valve block

Hi all,

Have you ever experienced a leak from around the soda valve? Drip. drip. drip. The liquid flows down the back of the splash plate coming frombetween where the valve and valve block meet. It can be quite a nuisance. In this blog, I will discuss one cause of the leak on a Flomatic 424 valve block.


This valve can be found on many Lancer beverage dispensers.  I did a previous video on replacing a valve block on a Flomatic 424 valve, which also tends to cause a similar leak. There is an accompanying blog released two weeks ago regarding that replacement, check it out!  Another reason for the leak is due to the quad seal stem. This is a little rubber insert inside the valve block that helps to seal the opening where the valve is inserted into the valve block. Over time these seals can become worn and will start to leak. They are basic to replace and should only take a few minutes. Call Donastar if you need to source the part or any restaurant supply component.


All you will need is a Phillips screwdriver and the replacement seal stems. First thing you will need to do before removing the valve is to ensure the water and syrups are off. Try running the valve once shut off to release any extra fluid in the line and relieve any built up pressure. Next remove the valve cover by lifting up. Turn the 2 paddles on the valve block towards the dispenser, left is water, right is syrup. Next you can unplug the micro switch wire by pulling firmly to disconnect. Lift the metal retainer clip up. If this is too snug to do by hand, a pair of needle nose pliers work great. Once the clip is removed you will have access to the valve block. Now you will notice the two rubber inserts (Quad Seal Stems). To access these inserts, you need to remove the 3 screw holding the small metal plate. Once removed you can insert your screwdriver into the hole gently and simply pull the old ones out. Insert the new ones and re-attach the metal plate with the 3 screws. Attach the valve by reversing these steps and you are all set to go!


For additional questions or concerns, please visit for contact information or call us at 833-366-2782. We are happy to help! We have lots of other content on diagnosing and fixing beverage issues, please check those out for a fast/free way to keep your cups full!


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