Replace Low Pressure Aluminum Pipe with Rubber Pipe for Air Conditioning System

Hi there. I have a 1999 Mercury Villager and a few days ago I decided to turn on my A/C, and to my surprise, there was no cold air blowing out. I opened my hood, connected a gauge to the A/C low pressure port, and it indicated that there was no Freon in the system. I drove to my local Walmart, bought a few cans of R-134a. As soon as I started refilling the system, I could hear a hissing sound in the back of my vehicle. At first I thought that my tire popped, but after further inspection, it turns out that there is a tiny hole in the low pressure aluminum pipe for the rear A/C. The “tiny” hole is able to empty all the Freon in the A/C system in about 25 min.

I lifted my car and started looking at ways to fix this leak. At first I thought about using some JB Weld, but after some research, it appeared that it wouldn’t work. Next, I thought about using an ATP splice kit, but there is a slight problem. The hole is right next to the frame of the car. The reason this is a problem is because the pipe is very stiff and doesn’t want to move. And I can’t cut the pipe without moving it. Also, the ATP coupling wouldn’t fit for very same reason (pipe doesn’t want to move). Finally, I can’t remove the entire pipe and replace it. The screws holding the pipe in place are rusted and weak. If I try to unscrew them, they will break. In fact, I managed to break one of the screws trying to do just that.

At that point, an idea popped into my head. What if I replace a portion of the aluminum pipe with a rubber pipe. The reason I said portion is because I would have to cut about 1/2 - 3/4 feet of aluminum tubing out and replace it with rubber tubing. As I said in the previous paragraph, the pipe dosen’t want to move so I can’t fit a coupling. But if I move about 3 inches forwards and 3 inches backwards from the hole, the pipe bends away from the frame of the car, so I would be able to cut the pipe and replace it with rubber tubing.

So my question to you guys is will my idea work? Can I replace a portion of the aluminum tubing with rubber tubing? What kind of rubber tubing should I use?

Thanks you in advance!

Edit - I decided that I’m going to replace the entire low pressure aluminum pipe going from the rear evaporator to the compressor. I am having trouble finding the aluminum pipe for my car online. If anyone knows where I can find it, please leave a comment with the link below.

***** Below are the photos to help you better understand the situation *****

Picture of how I want to cut the pipe

Another view of how I want to cut the pipe

The Hole

Before I broke the screw

After I broke the screw

You broke a screw already, skip band aid and do it right.

Nope. The rubber barrier hose you would need is specifically designed for A/C systems, rather stiff, and needs special equipment to splice and connect into the existing aluminum tubing. It also needs to be able to stand over 100psi, the high side needs to be rated to 450psi.

There are shops that can fabricate a piece for you if you bring the whole assembly in to them.

You’d be better off looking for a plug off set to eliminate the rear A/C altogether.

Yes, a section of aluminum can be cut out and replaced with a length of rubber hose but there are a few things to keep in mind.

It’s best if the ends of the remaining aluminum tube are flared a bit before placing rubber hose over it. This will require a flaring tool and the cuts should be made with a tubing cutter. A hacksaw can leave aluminum debris inside the line and care must be used to make sure it’s removed if a saw is used.

You MUST use a length of hose made specifically for A/C use and it MUST be a tight fit over the flares, be at least a few inches longer on each end, and clamped accordingly. Yes, that hose is stiff and requires a little wrestling to get it in place.

The dryer/accumulator should be replaced and the system evacuated (meaning to pull a vacuum) before recharging. Any recharge should involve adding some refrigerant oil also.

If you can remove the line without too much difficulty you might check with some auto parts stores such as NAPA or O’Reillys. They have various hoses and specialty tools and can possibly repair that line for you by crimping a replacement rubber section into place. The crimp clamps will hold better than screw types.
Hope that helps.

You replace the entire low pressure line assembly from the rear evaporator to the accumulator with one from RockAuto for about $125.00.


Why not just ALUMI-WELD it? It works just like Solder with a simple Propane torch…tho I always use MAP Gas which is a mixture of 3 Gasses (Methane, Acetylene and Propane) it comes in a Yellow can instead of Blue for Propane and burns a good deal hotter. Available at Home Depot. Its just like you were “Sweating” a copper pipe… Just clean the area to be repaired really well with Emery Cloth and maybe a Stainless wire brush? Just have the area clean clean and the Alumi-Weld will do the rest. I’ve used this stuff on Radiators and other thin pieces of Aluminum before with no problems. Alumi-Weld is usually available at Plumbing Supply houses and or Sears Hardware or similar stores…Walmart might even carry it? You can locate other avenues to purchase it locally by looking it up online. Otherwise just order it off the internet. That stuff would fix you up in a Jiffy and will be stronger than the original material.


Did you ever hear the story of the little Dutch boy and the leak in the dyke?

The little Dutch boy saw a leak in the dyke, so he stuck his finger in it. Then another leak appeared. So he stuck his finger in that one. Then another appeared…


In that area, a new aluminum tube will fail in a few years as well, maybe ten years but it will fail. The only way to use a rubber replacement is to remove the existing tube and take it to a shop that can swage the rubber hose to the ends of the current pipe.

I’d have to agree with @Tester on this. The third photo shows a lot of corrosion.

I think I’m going to listen to @Tester and replace the whole low pressure line going from the rear evaporator to the compressor.

Break the screws if you have to, knock the remains through with a punch and proceed from there.

Dont worry about those little bracket screws,a lot of ways to fix these…Aside from sentimental value is it worth getting involved in the cascade of aggravation,that will follow after this patch,on a 99 model vehicle that is starting to rust(the rest of the line is immediately suspect.