R12 and R134a are two different types of chemicals used in vehicle refrigeration systems. If you mix the two together, you can corrode the system and cause major damage.
The r134a will degrade the rubber and your refrigerant will leak out. The two are not to be mixed anyways, get the conversion kit, it gives you the new O-rings so you don't pollute the atmosphere and break laws. Best to have it done professionally, in order for the ac system to work properly after being opened it will need to be vacuum pressurized prior to the r134a being put in.
This should NOT be done... You will contaminate the whole system and have to repalce everythig A/C. The A/C will not work if it is mixed. Very expensive.
it depends on what is mixed together
R134a is a refrigerant gas
nothing happens
Nothing "happens".
Can you mix r134a with r410a?
Hydrogen sulphide explodes when it is mixed with oxygen.
Sodium sulfate dissolves when mixed with water.
BOOM!
nothing
you get warm.