We have recently been getting a large number of calls regarding air leaking from the exhaust ports on the Airpower and Jettronic electronic valves.
99.5% of these inquiries are not related to a valve problem but an issue with your gear system (especially with these poor quality cylinders being produced in Asia). In an effort to minimize these calls, I thought I would post some valuable information here so you can diagnose these types of leaks on your own.

Typically, if air is escaping the system through the exhaust port of these electronic valves, you have a internal cylinder(s) leak. What this means is air is passing the piston seal internally within the cylinder, allowing air to escape out the opposite port of the cylinder. This type of leak is quite different from a connection type leak and can not be discovered using the usual practice.
A simple method to test whether the leak is within the valve itself or in your gear system is to pinch off the opposing cylinder feed line(s) at the valve (IE: If the gear are in the down position, pinch off the gear up line. If using a multi-valve, pinch of both opposing gear and door lines). If the leak stops when the line(s) are pinched off, the leak is in your gear system, not the valve! If you still have a leak, it is possible the valve is defective and will need to be replaced.

Regarding the EV5U and EV5U-PRO valves, we have also had several calls reporting the brake valve will not actuate. These valves have a feature built in that deactivates the brake function with the gear in the retracted position. It is possible to plumb these systems in reverse, whereas the brakes will not function in the down position.
When plumbing the EV5U and EV5U-PRO valves, the first step is to make sure you are starting the programming sequence with the valve in the correct starting position. The simplest method of checking this is by activating the brake function of the valve. If the brakes operate, you are in gear down mode with the valve. If they do not function, flip the gear switch to the opposite position and test again. Once you have confirmed which direction is gear down, you can continue with the sequence program and all will operate as desired.

One further note regarding the EV5U and EV5U-PRO valves. They have a failsafe feature built in; should your gear switch be in the gear up position upon power-up, the gear will remain down. You will need to return the switch to gear down then back to gear up in order to retract the gear.

I hope this helps clarify some common inquiries regarding the operation of these valves, If you have any further questions, I am happy to assist....

Todd