Easiest Maintenance Item Ever - Replacing Valve Core


Well-Known Member
Here's what happened: I've got this cheap-o, off-brand electric compressor/pump, electric-drill type of thing. And for the last month or so, it seemed to be acting up-- it wasn't stopping at the target pressure, then wasn't stopping at all, then I wasn't sure it was reading the pressure right.

Anyway, after one tire top-off-- which was conservative, about 5 or 10 PSI less than usual per finger squeeze test-- I pull the hose off the valve... and the valve core comes right out with it, in the adaptor! Big pop, tire deflates completely.

Ordered replacements from the big e-tailer who I try to avoid, they arrived the next day, and... whoa, that was SO easy. Bonus: I'm not sure there's anything wrong with my compressor, it seems to be working perfectly now. Theory: The valve had some kind of malf in it, wasn't closing properly, causing the pressure reading to be off, and the auto-shut off to fail. All good now.

Moral of story: Get the tool and a bunch of spare valves if you are running tubeless. This is such an easy fix that if you suspect a bad valve, you can just try it and see if it works... (after deflating the tire)... for all of about a dollar.

I would add: Keep hands and face well clear of the tire whenever filling from an electric pump! Nothing bad happened to me, but still. Also, if your tire is totally flat, try to balance the bike up on a cinderblock or trash can or something (on the frame, which can bear weight, not the motor housing if it's plastic) until you can fix it so the tire doesn't lie flat with weight on it.
yes I went through valve cores like crazy using muc-off sealant. two or three fills and they would be toast sometimes. you can tell by how fast the tire fills when the valve is plugged. or push down on it and see how the air flows. I have found the valves in tubes tend to be loose out of the box.
Tube sealant can also build up below the valve in the tube stem. I'm in the habit of poking the chuck end of a 3/16" drill bit into the Schrader stem whenever I replace a valve core. If you do this, go easy so as not to damage the internal threads or the tube.