Solenoid problems.

Recently my team has been facing some issues with the pneumatic solenoid, whenever we pump air into the pneumatic system it just leaks out of a solenoid (through the holes that are supposed to release air when a piston is extended or retracted). We have tried changing the solenoid a couple of times but it has not worked. Are any other teams facing similar problems? and is there any way to fix this? Thanks in advance.

Have you tried wrapping Teflon tape around the fitting before screwing it into the solenoid?

This sometimes happens, but usually stops after a few seconds of pumping. I don’t think we’ve ever had to do anything special.

Yes we have tried doing that, it leaks out of a hole without any fitting. Thanks for the tip.

Is it a single or double acting solenoid.

its a double acting solenoid.

Thanks for the reply, our problem has also been quite inconsistent, sometimes happening and sometimes not, hopefully it will solve it self…

O okay good. The single acting solenoids start leaking air too much past 100 psi so I thought that might be the issue.

Try plugging those two holes with your fingers while pumping and it should hold after a few pumps. Otherwise, wrap teflon and electrical tape around the entire solenoid, covering those holes.

ok thanks for the tip, will try it out next week and see what happens. Thanks again.

Double-acting solenoids (like their double-acting cylinder counterparts) don’t have a return spring. Consequently, the spool (the valve unit inside the solenoid that switches the air) can get knocked to a position between “side A” and “side B” when the pressure is off, which can cause the leak you observed out the exhaust ports. It takes about 25psi of pressure minimum for the pilots to push the spool back and forth: so, power up the cortex so the solenoid gets a signal to move to the A-side, then start pumping up, and as soon as the pressure gets high enough, the spool will move into position and the leak will stop.

If it doesn’t stop leaking, you have a bad solenoid, which isn’t too common, but I’ve seen a couple over the years.

I can’t believe you had this problem today. I was just logging onto the forum to ask this very question. Today we had the exact same thing happen to our double action pneumatic solenoids. We replaced the one that was acting weird with a different one and in about 15 min the second one was doing the same thing.

We have had a new driver using the robot and i’m now guessing it’s because he is letting the psi in the tanks get below 25psi? Will test it again tomorrow. Thanks!

Thanks for the explanation and tips, the problem does seem to happen at lower pressures. Thanks Again.