X7 (and 407) Condenser Hose Repair

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EDC5
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X7 (and 407) Condenser Hose Repair

Post by EDC5 » 25 Jan 2020, 13:33

Before Christmas I noticed that my AC had stopped working, upon checking the pressure it was completely empty. I traced the leak to the condenser as upon filling with gas you could hear a hiss from the front of the car.

Replacing the condenser didn’t seem like a huge job so I set about that, unfortunately the aluminium pipes were corroded solid against the face of the condenser. I had to use a chisel to separate the pipe from the old condenser.

I managed to free the top hose successfully, however the bottom one snapped leaving half of it still in the old condenser.
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Oh bugger....

The problem with this hose is that it runs from the front bumper up the side chassis rail all the way to the bulkhead..... not an easy job to replace.

In fact, I think the hoses are put in before the engine. I honestly can't see how you can get access to change the hose without taking the engine mount off or taking the driveshaft out.

After speaking to a mechanic friend who said that in the past, he has had a new piece of pipe hydraulically crimped onto the flexible section of AC hose.

I decided to try a slightly different approach by using a donor hose end and joining it to my existing pipe using a brass flare refrigeration fitting.

First, I had to find a donor hose and I found a sorry looking 407 at the scrap yard.

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Luckily access was really good and the hose came off with no trouble whatsoever (guess I was just unlucky with my car!)

I cut the hose off the 407 much futher back than I needed to give me options as to where I wanted to make the join.

Here's a comparison of the donor 407 fitting and my corroded one.

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I did a test fit and found that I would join the entire length of the donor hose to the end of my original pipe (it would fit well with a 90 degree bend)

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Using the flaring tool, I put the end on the pipe:

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and then the union:

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I did the same with the small bit of pipe I had left at the end of my flexible hose section:

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And finally joined them together:

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The join held a vacuum and now I will wait to see if it holds before getting it gassed.

I’m not sure if this will work but the alternatives seemed very expensive / impossible, so we shall see!

Sharkie
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Re: X7 (and 407) Condenser Hose Repair

Post by Sharkie » 26 Jan 2020, 22:38

It will probably work. Aluminium is not best for flaring since it doesn't work harden the same way as copper does. And it reacts a little with brass too, just keep that part covered from salt, maybe spray it over with some clear coat and wrap in pvc foil.
Looks like a nice job and it will probably hold. Vac result only shows big static leaks. Best to fill with nitrogen and see what happens. R134a only holds like 20 bar on a hot day, so it's not such a big deal. You will find plenty of other leaks elsewhere. I've recharged mine but alu pipes started to leak as they were porous on the bends. Put a pipe screw clamp on it and a bit of rubber and call it a day :rofl2:

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EDC5
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Re: X7 (and 407) Condenser Hose Repair

Post by EDC5 » 26 Jan 2020, 23:54

Yeah, I've only ever used these brass flare fittings with copper but it was my only choice. Luckily the alu pipes were 3/8" so fitted my flare nuts; I expected the Citroen to use metric sizes.

Apart from this I was considering taking the car to a hydraulics shop and asking if they could join the two flexible sections of hose with a crimp union, but that could be difficult as access would be hard under the bonnet.

I hope this does work as so far the repair has cost £3 for the donor hose and about £2 for the flare fitting (and £60 for the new condenser).

I didn't know that about the reaction between brass and aluminium? Hopefully if it does corrode then that will seal it up good :lol:

I do have some clear coat spray so may do that, thanks for the advice.

I have the equipment for filling and checking the AC pressure but no nitrogen to test with. i might take it to a garage and have them pressure test it for me.

Sharkie
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Re: X7 (and 407) Condenser Hose Repair

Post by Sharkie » 01 Feb 2020, 13:02

Just fill it up after you pull a deep vacuum for a couple of days and check if all the fans are working properly. Compressor oil might be full of moisture and also the desiccant may need replacing since the system was open, you have to take this on your mind.
Spray all hoses with detergent and check for bubbles if anything.

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EDC5
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Re: X7 (and 407) Condenser Hose Repair

Post by EDC5 » 01 Feb 2020, 14:43

Fortunately, the filter/drier/receiver is integrated onto the side of the condenser so it has new desiccant already 😊

I think I am ready to trust it enough to fill with gas soon. Hopefully it will hold!