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A/C Hoses & Lines
A/C hose built to hold charge
Barrier and reduced barrier hose, beadlock fittings and the adapters between eras, for cars and trucks going back to when the system still ran R-12. Made up at both Long Island counters, frequently while the customer waits.
Why It Leaks
The refrigerant goes through the wall
Air conditioning is the one automotive system where a hose can be perfectly intact, dry to the touch, and still be the reason the system is empty by August.
When the industry moved off R-12, the replacement refrigerant turned out to have a smaller molecule. Small enough to pass slowly straight through the wall of ordinary rubber hose. Not a leak in any way you could find with soap and water, just a steady loss through the material itself, which is why so many systems from that era went from working to weak without anything visibly failing.
The fix was barrier hose, which carries a thin nylon liner bonded inside the rubber. Nylon is far tighter against refrigerant than rubber, and that single layer is the difference between a system that holds charge for years and one that needs topping up every season. Reduced barrier hose does the same job with a thinner liner, so it bends more easily in tight routing.
Which is a long way of saying that the layer you cannot see is the one that matters, and it is why an A/C line is not a job for whatever rubber hose happens to be the right diameter.
Inside The Hose
Peel back the layers
Drag from the outside in. Four layers, and only one of them decides whether the system still has gas in it next spring.
Outer cover
The skin that takes the engine bay. Heat, road salt, oil splash and the abrasion of sitting against a bracket for fifteen years. It carries no pressure and holds no refrigerant, but once it cracks, everything underneath starts ageing far faster.
Three Eras
What is in your system
Which refrigerant a vehicle was built around decides the fittings, the oil and to some extent the hose. Knowing the year gets you most of the way there.
R-12 systems
Vehicles built before the mid nineties. Original hose was non-barrier, which was fine for R-12 and is the reason a retrofit to modern refrigerant leaks unless the hose is replaced along with everything else.
- Typical years
- Up to the mid 1990s
- Original hose
- Non-barrier
- Retrofit note
- Replace hose, not just gas
R-134a systems
The long middle era, and the bulk of what comes across the counter. Barrier hose is not optional here. Fittings changed to a service port style that will not accept the older connections, which is deliberate.
- Typical years
- Mid 1990s onward
- Hose needed
- Barrier or reduced barrier
- Ends
- Beadlock, o-ring or flare
R-1234yf systems
The current generation on newer vehicles. Different service fittings again, and different handling requirements at the shop that services it. The hose itself still relies on a barrier construction to hold charge.
- Typical years
- Recent model years
- Hose needed
- Barrier construction
- Service
- Own equipment and procedure
Sizing
A/C sizes are their own system
A/C hose is called out by a number, and that number is not the hydraulic dash system. Four sizes cover nearly everything on a passenger vehicle or light truck.
Which size goes where varies by vehicle, so the old line is the reliable answer rather than a rule of thumb. Hydraulic dash sizing works on a completely different basis and is explained on hydraulic hoses.
Getting One Made
Bring the old line in
Original ends, new hose
Most A/C assemblies have a manufacturer specific block or manifold at one end that is not available separately at any price. It gets cut off the old line, cleaned up and beadlocked onto new barrier hose, which is what makes the job possible on vehicles nobody supports anymore.
A customer review on our profile describes exactly that, a forty year old line for a 1984 BMW rebuilt at the counter while he waited. That work sits on OEM hose assembly replacement.
One thing to sort out first
The system has to be discharged properly before the line comes off, and refrigerant recovery is work for a shop with the equipment and the certification to do it. We make the hose. We do not recover or charge refrigerant.
Have it evacuated, bring us the line, take the new one back and have the system recharged. That order saves a wasted trip and keeps the refrigerant where it belongs.
Before You Buy
Common questions
Barrier hose has a thin nylon liner bonded inside the rubber. Modern refrigerant passes slowly through plain rubber, so without that liner the system loses charge through the hose wall itself with no visible leak anywhere. On anything running R-134a or newer, yes, you need it.
That is the classic signature of non-barrier hose on a modern refrigerant, usually on a vehicle that was retrofitted from R-12 without replacing the lines. There is no leak to find because the refrigerant is permeating through the hose wall. Replacing the lines with barrier hose is the fix, and topping it up every spring is not.
Usually, and on older vehicles it is often the entire reason the job works. Manufacturer specific blocks and manifolds get cut off, inspected and beadlocked onto new hose. If a fitting is corroded through or the sealing face is damaged we will tell you rather than build something that will weep.
No. Recovery and charging need dedicated equipment and certification, and that is a job for a shop set up to do it. Have the system evacuated first, bring us the line, and take the new assembly back for recharging. We build the hose and nothing beyond it.
Bring the old one. A/C uses its own numbering, #6 through #12, and which size runs where varies between vehicles. Measuring the outside of an old hose gives the wrong answer because the wall thickness varies with construction. The old line settles it in seconds.
Regularly. Original A/C lines on older vehicles are almost never available, and rebuilding them from the sample is routine here. Bring the whole assembly if you can, and a photo of how it routed before you took it off. Ask at either counter or through the contact page.
Get It Made
Bring the line and the ends
Have the system discharged first, then walk in with the assembly. Size, ends and routing all come off the old part, and most lines are beadlocked and back in your hands the same visit.