When converting to a r134a you should recover all the r12 in the system first. Then pull a 30 inch hg vacume to dehidrate the system and make sure it holds that vacume for at least 30 min. if you don't loose the vacume you don't have a leak,if you do this means you have a leak and needs to be corrected before adding any refrigerant (r134a).
Now find out how much refrigerant r12 the system holds. This will be on a sticker under the hood some were. let's say it holds 38 oz you will need to do a little math. The r134a works of a higher head psi so you will need to take the amount of r12 in oz's 38 x .80 = 30.4 oz of r134a. this will be the proper amount you need.
you will put this in the suction side of the system. The high psi liquid line is the smallest line and the suction line is bigger.
I hope this helps you.
Darrell
Darrell ODell
June 2005
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