The head started leaking and I rebuilt it with new O rings and seals. However, it is still leaking. I know about the screw and have tightened it several times but it is still leaking. Any suggestions????

silicone grease on the "O" rings and surfaces they contact.

This never got much feedback so I'm necro'ing as I have the same issue. I found the OTHER thread where everyone is joyous that tightening the inner set screw worked. Unfortunately, it did not work for me.

Part #'s were provided for a repair kit which is now discontinued per Aqua Pure's site. This was that thread, but again, any part #'s that might help me are NLA and no one ever talks of actually tearing into the head of an AP101T except to say a nylon shaft broke:

[www.plbg.com]

I'm going to remove that set screw today and then not sure if I also need to remove the screw in the top of the handle to get it apart??

It seems to me this can't be rocket science and it must seal with just a couple o-rings? Maybe I'm over-simplifying?

It seems dumb to spend $100 on a new head if a couple o-rings will stop the leak.

Can anyone provide any actual tech on what to expect if I disassemble the head of an AP101T??

Ok well if anyone finds this in the future it comes apart with nothing more than a straight blade screwdriver.

If you're getting a leak from under the on/off handle it could be the two o-rings on the nylon shaft which passes through the body, but the most likely culprit is the pressure relief valve. It's a pinhole under the handle but is covered by the white plastic eccentric built into the shaft. You can see this if you remove the handle.

I honestly never reached a full understanding of how the valve works. My nylon shaft and eccentric broke during one of many test assembly attempts and I believe pieces wound up missing.

In the end I plugged the pinhole for the relief with a small brass screw from inside and made a stepped shaft to approximate the failed nylon-- being a machinist has its advantages. I don't need the on/off functionality as my plumber buddy was smart enough to put a ball valve just before the filter in the supply line.

So, I still have filtering capability but no more on/off handle on the filter itself.