Leaky air con

[marinaman]

Hi all
Just a quicky on the  BMW Mini as you chaps know all the answers.  tried on a Mini forum but got nothing.
bought few weeks ago and owner said had air con topped up.
After 2 weeks its warm again,  took to Kwik fit for their free service if it wont fill.

Their machine tested and the system held pressure.
Refilled.  2 weeks of cold air.
2 weeks later  warm again,  took back to KF who told me they would refund .
stated their top end machine would have not filled if a leak detected,  he calculated the system had lost 500grams from the amount put in over 2 weeks  which is a decent leak and the machine should have failed to fill.

He has refilled for free to assure the machine is not at fault and again it detected no leaks so refilled.

Bit beyond me,  anyone know why no leaks showing but its losing the gas after 2 weeks , i have a feeling it will leak out again and wondered about these leak stop agents,  found a decent sounding one online maybe better than the usual STP or Carplan type products,, wondered if anyone knew anything about them.
I know the system needs a dye etc etc but KF cant do that, may sell car soon anyway so just wanted a summer cool.
Heres the link to this supposed miracle sealer and the bumpf

https://www.errecom.com/en/product/extreme-ultra/
https://www.amazon.co.uk/gp/product/B06 ... UTF8&psc=1

EXTREME ULTRA ULTIMATE ONLY 6ML LEAK STOP FOR AIR CONDITIONING AND REFRIGERATION SYSTEMS EXTREME ULTRA is an ultimate Refrigerant Gas Leak sealant that solves all the problems related to small refrigerant gas leakages in AC/R systems. After more than 4 years of R&D efforts and thousand of tests, Errecom projected a 6ml dose leak stop that can work with all types of refrigerant gases included R32, R134a & R1234yf, EXTREME ULTRA 6ml new formula treats A/C and Refrigeration systems up to 21KW (6 tons). EXTREME ULTRA locates the refrigerant gas leaks and permanently seals them, without reacting to moisture and oxygen. EXTREME ULTRA is a polymer-free solution that repairs leaks up to 0.3 mm. BENEFITS Only 6ml can treat A/C & Refrigeration Systems up to 21 KW (6 tons) New advanced formula Less product in the system Permanently seals refrigerant Gas leaks both in metal and rubber components of A/C and Refrigeration systems Safe to AC/R system components Harmless to recovery unit components Non reactive to humidity and air Polymer-free Visible to any UV lamp Not flammable, Not irritant, Safe for the operator Compatible with all refrigerant gases, R32, R134a & R1234yf included Significantly reduces compressor noise Ideal for preventative maintenance