We have had the new pneumatics kit for about 2-3 weeks now. It is our first time using pneumatics. We have built a couple small systems to help us begin to understand how they work and what they can be used for. Today, my teammate tried to add pressure to the tank and the valve stem started leaking. If we get the lid on in time we are still left with some pressure but nowhere near the 100 psi we should have. If we don’t put the lid on, it will leak all of the pressure in the tank until its empty. Does VEX sell individual stem valves or is the kit just nearly useless now?
VEX only sells kits as of right now and there has been no answer as far as I know if/when they will sell separate parts. So your broken valve would cost $300 for a whole new kit. Also that is a custom valve as they don’t use the standard bicycle valve as in the past. Based on you saying you just started messing with pneumatics I assume you don’t have old parts. Look for an old SMC air tank that takes a standard Schrader valve (search this forum for links to part numbers and places to buy) maybe you can borrow used one from another team. Another issue with the new set is that even if you find a third party valve that fits, I’m quite certain it will not be competition legal. This official article tells you what’s competition legal. https://kb.vex.com/hc/en-us/articles/17984679227156-Legal-Pneumatics-for-Use-in-the-VEX-Robotics-Competition-VRC
@mbeem do you know if there will be individual parts available for sale by the end of the season? Some parts (especially the shrader valve) being custom means that teams are entirely at your mercy for getting replacement parts, so it would be great if this could be done before worlds.
Great news. Also individual air cylinders? Pretty pretty please?
My team had a similar thing happen when we tried using the new pneumatics for the first time. After investigating we found out that the valve stem came loose from the factory and we just had to tighten it with pliers. If it is genuinely a problem with the Schrader valve inside the stem then you can just buy a replacement kit from your nearest Autozone for about 10 bucks give or take.
Really good to know that inside the custom housing they used a standard automotive valve stem. Never bothered taking it apart so learned a new thing today.
@big_guy : OP, if you didn’t break the M5 thread (also make sure that little O-ring seal is there, could be another source of leaks if it fell off) - this is your immediate/cheap fix: tighten stem or unscrew and use a stem from another automotive/bike valve assembly.
The M5 thread is not broken, and the O-ring is still there. The air just comes out of where it goes in. Could you send a video or something showing how I can replace the valve?
Google found this one (among many others): Schrader Valve Leaking Air? Stop The Leak With This Easy Fix!
I don’t have a definitive solution, but this dude found a workaround.
Oh one last thing to this (sigh… editing posts…) don’t worry about that “valve core remover” tool. nice to have a specialized tool for the task, but I’d rather you invest into a quality pair of thin needle nose pliers, it works the same and will serve you in many more occasions.
Please before posting, look for others’ with the same problem. I made a post about the same thing
https://www.vexforum.com/t/air-tank-doesn-t-hold-air/122210
I found the source of the problem and fixed it! The schrader valve wasn’t broken it was just loose. I thought that maybe it somehow got loose so I just decided to try and tighten it with 2 zip ties (didn’t have thin pliers on hand) and it worked! It no longer loses pressure. Thanks for the information though, I will keep it in mind if the valve actually breaks in the future.
I did try looking it up, but your thread didn’t show up in my searches because I was specifically searching about the valve stem because I knew that’s where the air was leaking. It doesn’t matter now though, because I just had to tighten the schrader valve.