18913 no range shift

Having issues with an 18913. Transmission was rebuilt about 40k ago. Started out with a slow hi/lo shift at the beginning of the day, and also splitter would be slow in the am. After that it was fine the rest of the day. This week I couldn't split the top side. Last time it did this I added some air tool oil to the regulator and it cured it. No go this time. Removed the slave valve and it seemed slow. Took it apart and it was still slow, so replaced with new. Same thing. Now I'm getting air on the H/L line at the shift knob along with the S line. I've triple checked that I have all lines correctly connected. Have had the regulator apart and it's clean. At a loss for what I'm missing. Seemed like a simple stuck slave valve to me.

 

Finally figured out the issue. The regulator that was changed just before I had the transmission rebuilt was bad. Put shop air to each individual outlet, and all worked. Put it all back together and out shop air to the inlet on the regulator and no go. Bypassed the regulator and all worked. Changed it out and seems to be ok. These new parts have 0 quality anymore.