Air Conditioning.

TonyK

TonyK

True Classic
Last year I found that the High Side or compressor discharge hoses were leaking on my 87 X 1/9. Time to do some AC repairs.

For those of you that don't know much about AC systems the X has a good system with very good componets. The evaporator and condensor are made of copper. The hose fittings are all steel. Okay, means nothing, well keep reading. 134a and the oil used in the AC system become corrosive with moisture and attack aluminum. That is why most new systems loose condensors and evaporators. The X copper units will only leak by abuse and if that happens they can be repaired with a bit of copper tubing and a propane torch and solder. The fittings too are reusable. If you take a look at the X AC hoses they have some wild fittings that have custom bends in the fittings. So here is a small sample of how to rebuild a hose and reuse the fittings.

I purchase all my fittings from AC Source, see this Link.

http://www.acsource.com/hosefittingsbeadlock.aspx Warren Willingham is great to deal with so if you have any questions, just email him and he gets back to you fast.

So to reuse the fitting you must first cut off the Ferruel with a dremel tool 180 degrees apart.


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Next use a screw driver to split and remove the cut Ferruel.


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Replacement Ferruels can be purchased from the AC supplier and use a C clip to hold the Ferruel from slipping off of the fitting. I purchased this Master Cool Cripping set on ebay for $149 plus shipping. You can try and take the fittings to a Hydralic shop, but the tech has to know about barrier hose and that over crimping it will puncture the nylon inner hose and you will have a new leaking hose.


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Use a 3/4" wrench to hand tighten the cripping dies.

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Finished hose. New Barrier hose with old fittings. Also I will add that the fittings could be changed to use a new dryer canister to fit the X's front trunk.


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This is a picture of the Ferruels that come with C clips that snap into the groove of the old fitting.


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More to come as I progress.

4 years ago I did my son's 85 Mazda RX7, he seems to be the only one driving a First Gen RX7 in the summer heat with the windows up.

TonyK.

Grimsby Ontario Canada.
 
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Great Info!

Wow, that is really cool. I had no idea about the X's A/C. Everything I've ever heard was negative and the popular opinion seemed to be that the best idea was just to remove the whole thing!

I wonder how a more modern, efficient compressor would work with the other original components for less of a load on the engine.:hmm:

Living in Florida I've often wondered about retrofitting some sort of A/C on my '74. You need it here! I had looked at some street rod "mini" units, but if the factory stuff is pretty good maybe that could be a route to follow.

That is awsome info on the hoses too. I had always thought that you need big $$$ equipment to remake those. Looks pretty straight forward. Thanks for sharing.
 
Great write-up Tony, I look forward to more.

I always wondered how those high pressure hoses were assembled. Thanks for the info!

Pete
 
mblommel said:
Wow, that is really cool. I had no idea about the X's A/C. Everything I've ever heard was negative and the popular opinion seemed to be that the best idea was just to remove the whole thing!

I wonder how a more modern, efficient compressor would work with the other original components for less of a load on the engine.:hmm:
Click to expand...

I agree with Tony. I've long said that the A/C system in 1500 X1/9s is actually pretty good, although the condenser itself is way too small IMO.

The late compressors are Sanden SD508s (IIRC), and are great. No need to change those, but the early compressors definitely need to be upgraded.

Great post Tony!! I'll be sending you my spare set of A/C hoses for you to refresh. ;-)

Cheers,
 
Air cond hoses

tony,
So if we send you a leaky hose. You up for useing that nice crimping tool to replace a worn out hose with a new hose in for anyone?
 
Makes me want to dive into mine.

Awesome work, and awesome knowledge. I wish the heck there was someone like you in my neck of the woods. Custom thinking (aka "knowing what you're doing") like that is in short supply.
 
Let's look at this a bit closer.

jdot317 said:
tony,
So if we send you a leaky hose. You up for useing that nice crimping tool to replace a worn out hose with a new hose in for anyone?
Click to expand...


In doing the AC system repair the most difficult part of the job in my eyes is taking the parts off and putting back on again. So let's say you are going to venture down this road a bit. First off the compressor the Sanden 508 seems to be about bullet proof, but I went to CarQuest and bought a new shaft seal kit and installed it.

The expansion valve is common and was only $20, changed that out as well. Now we get to the hoses. Well if you go to the link I posted you can purchase hose by the foot and the ferruels as well too. Cutting off the ferruels and cutting a section of hose is simple stuff.

Now we get to the cripping. Normally I would go down to the Hydralic hose shop and a Tech would crimp them with their big press, but the guy knew not to crimp the living #$%^ out of it. He wouldn't take any money, but I gave him a $10 bill and thanked him.

Chances are if you do all the work, remove the hose, the ferruel and cut and assemble the new hose, you will find someone to crimp it for you. Then you can go back home and install it. Even if you have to pay someone to pull a vacuum and charge it, still not all that bad of a deal.

Sending me hoses to crimp would in short order chew up enough money to allow you to purchase the very same crimper I have.

Having an X with working AC, what is it really worth, take it to a shop and expect to drop $2000, spend $400 and I bet you can change all the hoses and buy crimper.

Thanks for thinking of me to crimp your hoses, but I will just be taking your money that you can use to get your AC up and running.


TonyK.

Grimsby Ontario Canada.
 
Moving along.

I removed all of the high side hoses and reused the stock fittings.

These fittings are custom made for the X and although there are some new aluminum fittings that are close the stock fittings can be reused and will save alot of adapting. Fiat/ Bertone used two different style of fittings. The fittings shown have a Silver soldered Ferruel and to reuse there are two options.

Totally remove the old Ferruel and weld in a washer to hold the Ferruel from sliding off of the hose or cut and use the Furruel to hold the new Furruel.

The first set of pictures shows me using a washer and TIG welding it to the fitting. ( A lot of Work )
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The other way to do this is to cut the Ferruel with the Dremel tool like this.


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Then file or grind to a round shape and cut a slit in the new Ferruel like this.


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This is another shot of how you need to modify the hose fitting.


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With the hoses all made up I have tapped the ends to prevent any dirt from entering the end of the hose when installing it.


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Here are a few pictures of the hoses installed.


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O ring failure.

The O ring must be seated and captivated before you screw the hose nut fitting on. See this picture.


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This is a picture of 2 failed O rings. The fitting was not totally tightened down on the large ring. The smaller ring did not seat correctly. Both distorted trying to seal the fitting joint.


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A correctly charged system should show a 30 degree difference from outside air temperature, show on a 75 degree day.

I also found this surprize as the previous owner jumped this switch out because of failure. Problem was that the remainder of the switch leaked. I only found this when changing the high side hoses. This is the place to start as the high side hoses see the most stress of about 325 PSI as the return hoses never see more than about 80 PSI and are not exposed the the weather as they are run inside the cabin of the car apart from the last hose to the compressor. The X has long hoses and requires more 135a than a standard car.


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I had a used spare from Matt Brannon from MidWest X1/9 to fill the hole, but the problem was that the low pressure switch too had failed.

Hoping to be leak free, time will tell,

TonyK,

Grimsby Ontario Canada.
 
Very nice detailed repair illustrations!

I'm very happy to have the AC functional in my '87 - I did convert the compressor fittings to R134a, but that's all.
 
See this link.

http://www.nostalgicairparts.com/ac/expansion-valves-23.php

It should be part 94-9873 just check what is on your car before ordering.

I have encountered another issue with my A/C system.

I runs fine and holds gas, but... no drips. The evaporator is frosting and the frost switch is faulty. The evaporator now freezes up and stops the flow of cold air. This system has a frost switch at the return line of the evaporator. It should close at 35 degrees F. Then open again at 45 degrees F. When the switch closes it energizes a return valve solenoid that stops the flow of gas returning to the compressor. This allows the warm compressed 134a to enter the condensor and defrost it. When the Frost switch opens the pressure drops in the evaporator and cools the air again. I suspect because of the long lines from the compressor to the evaporator this allows cooling recovery much faster than turning the compressor off and on and waiting for the 134a pressure to build. The switch made by Eaton does not have a listing on the NET. I have ordered a universal switch and when installed I will post pictures.

I have never seen a return line valve in any other system that I have worked on.

TonyK.

Grimsby Ontario Canada.
 
I put is a used Volvo240 expansion valve, since I had one handy. They use the 2 capillary tube version, so I just capped & soldered the unused one.

My problem is that the high side pressure climbs to over 350 * idle, and the evaporator barely gets tepid. The expansion valve gets cold & a little frost on the low side, but the line out of the Evap is barely cold at all. I couldn't get the temp out the vents to register less than 80º * idle. On the road, it dropped to 65-70º. I have an aftermarket push fan bolted to the face of the condensor.
 
Pressure at idle

That idle pressure is okay providing that the condensor fan is off. The fan should kick in at about 250 PSI which will drop the pressure drasticly. Of course the other issue is flow through the expansion valve. The valve must open enough to allow the gas to flow and expand. If the system is over charged you will have the same problem as the gas cannot expand quickley enough and abzorb the heat in the evaporator. Your low side pressure should be no higher that 30 PSI and never a negative value. If the return is above 30 PSI the system is over charged. If the return is a negative pressure the sytem is under charged.

My system is cooling so well that the low side line from the evaporator is frosting and I am just making a big ice block. Turn the AC off and then the water starts to flow out the bottom drain. This should be automatic and not a manual fix. Will supply pictures and a write up when sorted out.

TonyK.

Grimsby Ontario Canada.
 
That pressure was with the condensor fan running - it kicks in * 250psi, but the high side doesn't drop (at least not when idling). Low side doesn't go over 30psi. I only put 3/4lb of R134a into it, as the high side was climbing rapidly.

I mounted the fan directly on the condensor, it has to be better than the old Fiat fan

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no room for anything bigger/wider behind the grille.

I'll order a new expansion valve. Trying to find a source for a short r/drier that has the male/female combo fittings so I can do that at the same time.
 
Frost switch.

Well my A/C has been working for 3 months now but I have noticed another problem, no drips from the evaporator when the unit is running and the return line becomes frosted over. What is happening is that I am making a big block of ice which in short order stops the effective cooling of the passanger compartment.

Looking at the diagrams the Fiat system has a frost switch that is held on by a clip on the return line and the clip shares the same spot as the capilery for the expansion valve. What is supose to happen is when frost or the temperature drops to 32 degrees at the outlet the frost switch closes and energizes the frost solenoid valve in the return line of the A/C system see pictures.


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I took a picture of the hose from the compressor return and the frost valve to show it's location, which is under the cooling system expansion tank. Here is close up.


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What happens in this system. When the frost switch closes it energizes the frost solenoid valve and allows the pressure to build in the evaporator to high side values. Since the gas cannot expand at the expansion valve the warm Freon is pushed into the evaporator to defrost it. When the Frost switch hits a temperature of 45 degrees F. the switch opens and the sudden drop in pressure causes the evaporator to rapidly cool. The compressor will continue to run even if there is no flow but when the temperature of the compressed Freon hits a preset valve ( switch is just infront of the Dryer) the compressor clutch drops out and unloads the compressor.

Complicated, YES.

What I found was someone had removed the Frost Solenoid. Most likely because it was defective or the frost switch was stuck closed.

I ordered a new frost switch from Nostalgic Air Conditioning but the contacts were normally closed and open when frost occurs or at 31 degrees F. and close at 45 degrees F.


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The capilery was wound around the return line of the evaporator and I modified the clip to hold the expansion valve capilery to move closer to the hose fitting.

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Completed the new switch is installed on the side of the heater box with one screw. The compressor clutch yellow wire was cut and when frost is detected it opens the feed to the clutch and air solenoid.


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Now my drip line drips when the A/C is running.

TonyK.

Grimsby Ontario Canada.
 
Nice Work! Thanks for the detailed pics & part availibility - good to know where replacement parts can be found. Did you find a replacement drier? When I looked on their site, I only saw "shorty" male/male setups, no female/male like the X1/9.
 
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