AC hose question

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.

Just FYI- the flow is the other way, from the dryer to the TXV ( thermostatic expansion valve ). Compressor discharge is out to the condenser, through the liquid line to the filter/dryer, etc.

Yes, if it is in good shape, threads are ok and you can replace the O-rings, by all means reuse it. Post a pic - most are a hose from the dryer to the TXV, but I haven't paid attention to the A body stuff like I do the B body.

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.

Thanks guys, just what I needed. The compressor, drier, condenser, and evaporator are new. The metal tubing I want to reuse will be thoroughly cleaned. I'm gonna post a pic of how it attaches to the firewall end - it threads onto another fitting that's metal/ rubber. You can tell I'm new to AC work.

Here are a couple pics of what I'm trying to reuse. I figured I could have a new hose fabbed since this one is old and too short anyway. Is it worth trying to save these, or should I bite the bullet and buy new hoses for under hood?

I hope to be working on my cars AC soon, My plan is to cut off the crimped connector on the hose and then replace both the hose and crimp connector. I am going to buy a crimper but I would think a local AC repair shop to you could help you out.

In my second pic above, what is that canister thingy on the right side of the hose? Some type of filter? Don't remember seeing them on all AC systems.

That's a muffler. Really.

Supertruck - take apart your TXV capillary tube and compensator tube (slides out) from the suction line before they break. Not reusing the suction line are you? Then again, you'll likely get a new TXV w/ the kit.

Demonic said:

That's a muffler. Really.

Supertruck - take apart your TXV capillary tube and compensator tube (slides out) from the suction line before they break. Not reusing the suction line are you? Then again, you'll likely get a new TXV w/ the kit.

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You may want to consider replacing the Expansion (TXV) valve as well. If it's stuck from sitting for many years it will be a headache that will cause you to remove your new refrigerant and replace the valve. You are going to need new hoses made up to mate with your new Sanden compressor with the fittings angled properly to mate up with the compressor fittings. You need to first mount the compressor on the engine to see what that will look like. I've used a company called Cold Hose in Florida to rebuild A/C lines and they did a great job for $30 a hose with fast turn around time. That can on the end of the suction line is a muffler to deaden the impulses of the RV-2 compressor. It also has a fitting that matches the RV-2 suction port, but will not match your Sanden. Sanden compressors also have their suction and discharge ports in certain positions and may need to be "clocked" to fit your application. Mount up your compressor and you'll see what I mean.

Thanks Pete. I have the compressor mounted now. The old stock hose is too short so I know I'll need a new one. Since I've never messed with AC before, I'm unsure how to get the hoses with the length I need plus the end fittings I need. Plus I really like the idea of the metal tubing I have now for one of the hoses - much neater than another big hose running there. I may end up taking it to an AC service center and let them do the hoses for me.

supertruck said:

Thanks Pete. I have the compressor mounted now. The old stock hose is too short so I know I'll need a new one. Since I've never messed with AC before, I'm unsure how to get the hoses with the length I need plus the end fittings I need. Plus I really like the idea of the metal tubing I have now for one of the hoses - much neater than another big hose running there. I may end up taking it to an AC service center and let them do the hoses for me.

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Off the compressor you'll need the flexibility of the hoses for anything that connects to body components. The Sanden compressor fittings are standard A/C fittings #8 I think, and you'll most likely need right angle ones. But, a good A/C shop should be able to make up the hoses for you. As you install A/C components keep open ports sealed with plastic caps to keep dirt from getting in. And again, you'll need to find out what the oil capacity of that Sanden is. You will need to reuse the evaporator suction line end with the ports for the expansion valve sensing tubes. The shop will have to redo that end by brazing on a new barb fitting to handle the new barrier type hose.