GENERAL PROCEDURES 1 . Perform a leak test and replace any leaking components. Since HFC‐134a has a molecule that is about 80% the size and weight of a CFC molecule it will leak from rubber hoses and O rings. Replacement hoses and O‐ rings must be made of non‐permeable material. NOTE: Rubber hoses and O‐rings used in CFC systems become permeated with refrigerant oil. The refrigerant oil fills the pores & creates a reasonable seal. Although it is ideal to replace all rubber hoses & O‐rings with the non‐permeable type, these oil soaked rubber components will provide an acceptable seal for HFC‐134a.
