Replacement for Valve Stem in the new V5 pneumatics kit?

Not sure what the defect is… But It’s safe to assume my students. I assume this is sourced from somewhere else. Does anyone have an idea? The web page just says, Valve Stem.


Since no one else has replied yet, I’ll give you what info I can… I am not yet familiar with the new pneumatics kit, but here is the replacement Schrader valve we ordered from McMaster-Carr this year for the old SMC kits.

I don’t know any of the sizes for the new kit but the linked page has many different options. Perhaps you could find a matching part there.

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The thread size is M5. The schrader valve is a custom made part for VEX. We do intend to sell the various “jewel cases” in the pneumatics kit, so it’s coming. I don’t have an exact timeline, but I’m hoping we’ll have some in stock by end of the year.

And yes, M5 thread fittings can break if they are torqued too much. Be careful, the fittings will seal well below the breaking point. Snug is good enough.


Given that the entire kit can’t function without this part, surely there is some way to purchase a replacement part from VEX, maybe through Support?

I could just use an unofficial part for now and swap it for competition. But for now, I’m probably going to have 2 kits per team given the interest, so I’ll have enough of them floating around.


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Would it be possible to glue a piece of the pneumatic tubing to the broken end of the stem and then attach the other end of the tube to the air tank via standard connector?

Ideally, it would be wise for GDC to either allow such remote Valve Stem connections before lots of them gets broken (just like they allow USB pig-tail extensions) or let people buy replacements from a third party vendor like


This is not an official ruling, but please do not trust glue or adhesives to hold upwards of 100psi. There are probably some out there that are capable, but there are certainly more types that are not.


I’ve seen this with teams of the old kit - they pressurize the system with a 4mm tube and then use a shut-off valve to isolate the system. It’s a smart way to do it, as the Schrader value disconnection does lose some air pressure by the nature of it (I’ve seen a 20psi loss if you’re clumsy about it).

Or I’ve over-pressured the system knowing it’s going to have losses when it’s disconnected from the Schrader air supply. The GDC rules are 100psi at the start of a match, but the system can handle a bit more. Just make sure you’re with in the GDC rules at match start.


a description is here.


Ours did the exact same thing

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@mbeem Given that this seems to be at least a non-isolated incident, is there a way to purchase a replacement from VEX support?


Can the new V2 Pmeumatics kit have the Schrader valve replaced with the part used with tubing to do this method?

@TrialAndError That’s fine, but you’ll need a valve to shut off so the air does not leak out when you disconnect from the external supply.

@sazrocks Getting spare Schrader valves (among other components in the system) is in the works, but unfortunately, I do not have an ETA at this time.



So @JRstearns 's team’s only option currently is to buy a whole new kit? That’s really unfortunate, and makes these kits really risky to buy for competition teams. There needs to be a way to get replacement parts, and soon, before the competition season really gets going.


Given that VEX is currently not providing any replacement components for the new pneumatic kits, I’d recommend all teams who purchase these kits stock up on remote fill Schrader valves from the old pneumatics kit.

If your fill valve from the new kit breaks, you can replace it with a straight or angled fitting and run a tube to this component to still be able to use your $300 kit.

This would be a great component for VEX themselves to include in the new kit.


It really does stink but it’s not looking good for us right now. :frowning:

This would work. You can use any value you want as long as it doesn’t remain on the bot. This would also help keep it at 100psi. with the shutoff valve.


Looks like the Q&A provides some relief: Legal Substitutes for discontinued pneumatics parts : Robot Events

* KQ2S04-M3G is a legal substitute for KJS04-M3
* KQ2L04-M3G is a legal substitute for KJL04-M3
* The use of KQ2LO4-M5A would not be legal, as it adds functionality not provided by the discontinued parts

Ours just broke! Could you please be more clear on how to use the depicted tire valve assembly to make this ridiculously expensive, new pneumatics kits work with “straight or angled fitting” and a tube? What is a straight or angled fitting anyway? Pictures would be extremely helpful!

You would think for the price it will be better quality