Need help with SMC solenoid valves

We have our pneumatics system all connected. We are using SMC single solenoid valve SY3140-6LZ with the SY3000-27-1T subplate. We put in the gasket and mount the valve on the subplate with the screws provided.

The manual seems to say connect air supply to P and connect A to one end of cylinder and connect B to other end of cylinder. We are using it to shift the AM shifter transmission. It seems to be working. In one position, it is okay. However when we switch to the other position, air starts coming out slowly but constantly from EA or EB which I assume are the exhuast ports. We tried to plug that port but then we can not shift.

What are we doing wrong? Can somebody please help?

SMC valve.jpg

SMC valve.jpg

How much air pressure do you have going to the solenoid valve?

I think you have it plumbed properly.

At first we use 30psi, then we increase to 40psi and it still did not work.

Did you double check to make sure the gasket is sealing properly?

Maybe try soapy water to find leaks?

The gasket is the only thing I can think of. When I put my finger on that port then no air leaks, so it is not leaking anywhere else. I guess if the gasket is not put in correctly, it will come out through another port. I will use another SMC solenoid valve and see if the same thing happens. Thank you.

Edit: I will post what I find out after Friday. We don’t meet on Thursdays. Some of my over dedicated kids want to work until 4am this Friday and then work our normal 8am to 4pm on Saturday. There is no internet access where we work.

The mounting design on those valves is not fantastic, with only those two little screws. I’ve had trouble with them before. I’d take it apart, inspect the gasket, and reassemble, making sure those screws are tight. I’d torque them back and forth incrementally, not all the way on one before the other is tightened at all.

It sounds like you might have a bad seal in your cylinder. The EA and EB parts are the exhaust ports for the valve. When you shift the valve, pressure is applied to the B port, and the A port is open to atmosphere. If air leaks across the piston seal, it will escape out the exhaust port.When you have a leaky piston seal, it usually leaks in both directions (air will seep out in either position) but there are conditions that will cause a cylinder to leak in only one direction. Try removing the cylinder from the equation (plug bot A and B ports). if you still have leaks, it’s the valve, if not, it’s the cylinder.