Refurbishing AC rubber lines. What are they made of?
 

I'm gonna tackle the AC system next. Gonna take out all the lines and rather that buying new (expensive), gonna take the lines and have a local hydraulic shop replace the rubber parts onto the hard lines. Anyone know what special rubber (butyl? urethane?) is used for good quality hoses for our AC system? It would be nice to know ahead of time what "should" be used to handle r134a and oil for many years of service.

thanks!

https://www.google.com/url?sa=t&source=web&rct=j&url=https://m.alibaba.com/showroom/r134a-goodyear-galaxy-ac-hose.html&ved=0ahUKEwiZxp6UmK_bAhWEzVkKHeBNAdoQwqsBCDEwAQ&usg=AOvVaw2WAN H9ricFcrNhNVIqOQog

they should have the correct hose (tell them its air conditioning hose, barrier/barricade type for R134)

Hey Jaime! I'm doing something similar and you just gave me a super tip! Didn't realize I could replace a torn hose so cheaply.

However, my hose in question runs from the compressor to eh evaporator; it has a split in it. Peeking into the split, I see metal, kinda like a coil. Is it possible that hose is actually a flexible metal hose wrapped in a rubber casing?

As an FYI but a different use since you mentioned Butyl.

Butyl Tape is used to seal the tail lights and the heater fan assembly. The product works well. Not to be confused with the Butyl Urethane hose if you happen to do a search on RL so not to confuse the 2 Butyl's

Hey guys thanks! So, just specify that it is for r134a and they should know about it. I figured this is a contentious area with the EPA as the law requires the use of specialty hoses but I wanted to make sure I was aware of the specifics in hose material composition to hold my local business honest ;-)

Hey Dan, it may be that spiral metal is to keep things from kinking? I have read that the change to r134a resulted in new hoses as the actual gas permeates the hoses used on r12, hence the yearly "top-off" and loss of r12 to the atmosphere from ac systems using r134a today. That's a lot of vehicles through out the world.

Thanx all

Jaime

simple explanation is that R134 molecules are smaller than R12.
the original R12 hoses, being rubber have pores that R12 couldn't escape from but R134 can.

R134 "barricade/barrier" hose is designed to account for this so it doesn't leak out.

R12 hose design

R134a hose design

The hose from the evaporator to the compressor is the suction side of the system, so maybe they put a metal coil inside the hose to prevent the hose from collapsing under some operating conditions?

Also, if both of the metal piping ends of your original hoses are curved fittings you need to mark their relative direction to each other so that your new hose may be reassembled with the same "clocking" position as the originals.