You can always PM me Vic anytime you like.
OK, if you look at your new end cap you'll see that drilling and taping probably won't work and would reduce the integrity of the end cap. Replacement in your cased is called for. First remove the high pressure tubing. You'll need two open end wrenches, a 13/16" and a 7/8" I always advise against using adjustable end wrenches here. Once the high pressure tube is removed leave the male side of the fitting in the end cap. Now remove the two SS 1/4" plugs (one is shown and the other is on the opposite side unless the product tube is there, then remove it as well) I highly suggest that you find 1/4" plastic plugs to replace them, I've seen end cap failures at these points as well with the SS ones. They are no longer used because of this. It is a low pressure product point so the plastic ones are perfect. Now with the procedure I gave above un thread the collar ring. The collar ring is aluminum
so you can whack the piece of wood/starboard pretty good. The end cap is plastic and the high pressure vessel is re-inforced fiberglass
. As the collar ring un-threads it will bump into the SS fitting you left in the end cap, at this point take a screw driver and gently pry between the SS fitting and ther collar. You will see the end cap move outwards a small bit. Continue un-threading the collar and use the screw driver technique again, you may have to do this three or four times before the collar totally un-threads. Now with the collar and end cap removed remove the SS fitting from the end cap and then push the end cap through the collar. Compare the two end caps. You need to make sure your old SS fitting easily threads into your new end cap. Check to see if the old SS fitting has an O-ring on it. If it does it should fit fine, if it is sealed with teflon tape it may not thread into your new end cap and you will need to get the right SS fitting. Let me know on this. DO NOT force this fitting to work or you'll be getting another new end cap. Look on the inside of the new cap. There should ether be one or two interior
O-rings and there should be one exterior larger O-ring. If not hopefully you end cap came with new ones. It is possible to use the old ones if you don't have new but the interior
ones are fun to get in. Once this is done, give the O-rings a coating of silicone grease and the exterior threads of the membrane vessel a little silicone grease and reverse the process. Be careful not to cross thread the collar threads onto the vessel, take your time. Once the ring has basically bottomed out on the threads a really good hand tightening is all you'll need to seal it. Don't be tempted to whack it tight like you did to remove it. Replace the SS fitting and then the high pressure hose. Be careful when threading the SS fitting back into the end cap, once it bottoms out you should be tight enough, DO NOT over tighten, remember this is SS threading into plastic. These fittings are reusable many times so don't worry. Using the two open end wrenches re-tighten the SS high pressure fitting. Be careful not to move the the fitting that threads into the end cap. A lot of pressure here is required so be careful.
If you need any help don't hesitate to just PM me and I'll give you my phone
number so you can call me while you are doing this and I'll walk you through it step by step. Good Luck