I installed the HF air compressor auto-drain kit and had a hell of a time working with it, only to have the nylon 250PSI tubing keep popping off of the cheap t-fitting they include in the kit. Not only that, but the tubing actually started melting.
I went to the local hydraulics shop and got the 250 psi nylon air hose for truck brakes, which is reinforced w/fiberglass, and this hose is MUCH easier to work with - the wall of the tubing is thinner.
I also got a decent T-fitting to replace the HF junk one that had a total of 4 pieces - the T itself and the three nuts. The new one has 7 pieces (3 ferrules), and works like all the other plumbing fittings I have worked with in the past.
The existing hose on the compressor for the pressure valve is about as thick-walled as the HF tubing was, but with a little perseverence, a small open-end wrench and some gooseneck pliers, I was finally able to get the hose on the integral tube support and the ferrule down far enough to start the nut.
Once the original line was connected to the tee at both ends, the new tubing worked great - no problem at all on the new fitting and hand tighten onto the integtrated tube stiffener and clamp down with the nut on the fitting down at the auto-drain valve which I did not change.
I used the compressor today 5 times more than what had caused the previous tube to part ways with the old fitting and start melting with no problems.
To anyone out there that has troubles - try just the tubing first - that was 90% of all of my frustration in the original install.
I don't regret getting the better T-Fitting, but it probably wasn't necessary - I just did not want to make two trips - besides, I feel a lot more comfortable with a ferrule in there.