AC hose question

supertruck said

My 73 Sport was a factory AC car. As part of my build I'm replacing the underhood pieces. Have a Sanden compressor and new condenser and dryer. My question concerns the hoses. On the stock setup, the hose from the small firewall connection to the dryer was a piece of formed metal tubing. I can make this work again, and it's not as bulky as another hose would be. Is there any reason this piece won't work as long as it's cleaned up? I am an absolute novice with AC and so don't know what works and what doesn't.

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Hi,

There's no reason you can't reuse the metal line if it it in good condition and not all rusted up. If you are new to A/C work some things to consider- you want to get all traces of the old mineral oil out of the system by flushing the evaporator and any lines you reuse. If your new condenser is a universal parallel flow type your old stock plumbing will not likely match up to it without some modifications. The receiver drier should be the last piece you replace before you vacuum out the system. Never leave anything open on the system with the new receiver/drier in place. It will absorb moisture and become useless. If you are going to R-134A which you likely will be, use the proper oil. Polyester based oils are compatible with both R-134A and old er R-12. It will also mix with traces of the old mineral oil in the system. PAG oil does not go well with mineral oil if there is any left in the system. The old RV-2 hose ends will not mate up the the Sanden so you will need new hoses. Study the shop manual on A/C systems in these cars and how to change O rings and things like that. Follow the oil capacity for your Sanden and not the shop manual RV-2 amounts. Use new R-134A compatible O rings, usually green, not the old black R-12 rings. Make sure the fan shroud and any hood seals are still in place and the fan thermal clutch is in good condition. you want the maximum air flow through the condenser.