Great post and info, one thing that I think would be extremely beneficial to new users is getting a Dr. Drop kit so they dont have to cross their fingers and test with coolant for 24hrs, that just seems insane to me.  It could save them a lot time, and a whole lot of trouble.  Just like flushing your rads, doing a pressure test of your components before putting coolant in them.  The pressure tester can let you know of things you might not always be able to see, such as bad O-Rings or a manufacturing defect.  This unit has saved me many times and I am not joking when I say that.  Hope this helps. 
https://shop.aquacomputer.de/product_info.php?language=en&products_id=3415
 

There are different ways to test for leaks -- the one you listed is one of them -- I'm suspect about the 1 hr test telling you much about small leaks
 
Very small leaks - or if something comes loose - are what you find with an extended test by pressurizing the loop with your pump.
 
Because water / coolant is Not compressible it "could" still be an issue if you only use air pressure.
 
Leak-down tests such as the one you listed are better than nothing -- but not as good as running the loop
 
Remember a proper leak test --ONLY powers the pump -- No power to anything else
 
If loop does leak you do not want to have an electric short that kill your MB, CPU,RAM, GPU, PSU, or other things in your build
 
Remember---> everyone has leaks for time to time
 
AS you gain experience; you may be comfortable with shorter leak tests -- the risk is yours to take

Cool GTX
There are different ways to test for leaks -- the one you listed is one of them -- I'm suspect about the 1 hr test telling you much about small leaks
 
Very small leaks - or if something comes loose - are what you find with an extended test by pressurizing the loop with your pump.
 
Because water / coolant is Not compressible it "could" still be an issue if you only use air pressure.
 
Leak-down tests such as the one you listed are better than nothing -- but not as good as running the loop
 
Remember a proper leak test --ONLY powers the pump -- No power to anything else
 
If loop does leak you do not want to have an electric short that kill your MB, CPU,RAM, GPU, PSU, or other things in your build
 
Remember---> everyone has leaks for time to time
 
AS you gain experience; you may be comfortable with shorter leak tests -- the risk is yours to take

Sure thing, great info, yeah having a spare small PSU to run the pump or using a 24 Pin ATX bridge tool .  Never want to do a leak test with everything powered on.  I still will stand by this tool since it can save an individual a lot of trouble.  If something is airtight it is watertight.  

I tried to be specific, so if anyone New to Water Cooled reads this ....... just running the bases
 
My industrial experience for leak-down testing is usually >30 psig for 12 hours ....
 
I'll admit I've never tried the product you listed or any competitors product
 
What brand / part number are those Quick Disconnects (QD) fittings pictured in your Mods Rigs page ?

Cool GTX
I tried to be specific, so if anyone New to Water Cooled reads this ....... just running the bases
 
My industrial experience for leak-down testing is usually >30 psig for 12 hours ....
 
I'll admit I've never tried the product you listed or any competitors product
 
What brand / part number are those Quick Disconnects (QD) fittings pictured in your Mods Rigs page ?

The QDC's I use are CPC Male (NS4D22006), Female (NS4D17006), these are the QDC's that EK sells them and they only cost $18.22 which is a steal if you ask me, yes you get the whole QDC and not this of having to buy two pieces to get one QDC.  These have a 10mm barb for tubing.  I would not use the EZ-Nylon clamps they come with though, they are absolute junk.  They are a plastic clamp and even tightening them with "Soft Jaw Plastic Pliers" tears them up.  You can use this clamps, I helped setup my friends loop with them, you just have to tighten them to 2x Audible clicks of the clamp and no more or you will scrape the plastic on them.  If you get these QDC's  I would recommend the Bitspower (Bitspower Luxury Clamp For 5/8" OD Tube).  These are 100 times better because they are metal and you get to tighten them via an Allen key so its very easy and wont get damaged.  These are plastic QDC's and are well built and of excellent quality, they are also very chemically resistant, so your home brew or pre-mix coolants would be safe, you can check there chemical data sheet to know for sure. I tried the full metal ones in the past and they are giant and can be difficult to install in tight spaces, plus they require most of the time 2x compression fittings which makes them to large in smaller cases.  Also when you disconnect these QDC's there is not giant gush of liquid or spill, usual just a few drops inside the QDC's so they are very safe. 
 
https://www.bitspower.com.tw/index.php?main_page=product_info&cPath=172_238_239&products_id=2841
https://www.cpcworldwide.com/Product-List/Product/1679
https://www.cpcworldwide.com/Product-List/Product/1679 
https://www.ekwb.com/shop/ek-qdc-10mm-gray
 
As for the Dr.Drop I recommend you try it out some day or you can make your own, all credit goes to B Negative at Overclock.net, his post was the one that got me interested in this alternative.
http://www.overclock.net/forum/61-water-cooling/1534282-how-correctly-leak-test-your-loop-101-a.html 
 
 

I have one noob question.
Where is better to install drain valve.
On Inlet or Outlet Port.
 
For few days should arrive, I bought XRES Revo 100 Glass, small version for better compatibility with different cases.
One of 3 Top ports will be inlet. That mean bottom Inlet will be closed, I could install Drail valve there on Outlet port.
 
 

 
 
1 .Outlet option is Male to Male rottary - X Spliter - waterblock and other end to drain valve, one will be closed with Plug. 
2. Inlet will be closed with Plug or Male to Male Rotary - Drain Valve - Plug.

Place the drain at the lowest point of your system, with easy access
 
You should Never run the pump dry as water cools and lubricates the pump
 
I prefer the line leading back to the pump or the lowest radiator in the rig

still like the Vertical orientation a little better. Horizontal one and like if it was mounted is the fill port stuff. does it matter much no...no  don't worry about the drain, leave ya some more slack with hoses and just pull it out and dump it from the cap man and jump it lol

Is there really a need to go to watercooling if you delid and go liquid metal?
Maybe not as much fun / expensive / cool-lookin' ...
My cpu (admittedly old but kinda why I'm asking/posting) gets unstable before any thermal issues arise.
(with a joke of air cooling / stock-ish intentionally just to see)

sdcgsb
Is there really a need to go to watercooling if you delid and go liquid metal?
Maybe not as much fun / expensive / cool-lookin' ...
My cpu (admittedly old but kinda why I'm asking/posting) gets unstable before any thermal issues arise.
(with a joke of air cooling / stock-ish intentionally just to see)

Many good AIO coolers that are better than any Air coolers for someone who does not want a to do a custom loop
 
Water is much better than air to move the thermal load from source to discharge point.  With the radiator dumping the heat outside of the case it is effective.
 
Most users also like the fact that they can dial back on the fan RPM for a quieter experience with liquid cooled system