Air Conditioning repair - FAS 2.0

[VicVan]

At the bottom of this first message, I will include the relevant information collected in this thread. Original message:
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Hi all,
I am repairing the stock Air Conditioning in my 1990 Westy. I've never used it since I bought the van seven years ago. The compressor had a crack, and a shorter belt had been installed. When installing the FAS engine 3 years ago, I left the compressor (new) unconnected.

I will change condenser, receiver-drier, all hoses and fittings (most likely Aeroquip EZ-Clip system). The compressor is new (came with the 2001-2005 Jetta AVH engine in the FAS kit). The sticker says R134a, so I am thinking of filling the system myself with Redtek.

I am going through the A/C master topics, which prove very useful.

A couple of questions:
1/ How do you decide how much PAG oil to use?
2/ How do you decide what size of hose to use?

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Summary (last updated Sept. 14th, 2025)
- Quantity of oil will be 240 cc (see page 2)
- Size of hose will be similar to original sizes (See DeLvxe's parts list page 1)
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'90 Little Blue Truck, 2WD auto, FAS GenV 2.0 NA (AVH)

[VicVan]

A few pictures of the easy part. I was suprised by how good and clean everything looked, compaared to what some of you have posted. Was the A/C used at all? Who knows.

Looks brand new!

I have yet to test the blower motors, but the resistors look good. Their mounting brackets are the only things that broke. Even the drain pipe bits are in good condition.

Evaporator

I will be modifying the wiring as per the Wiring master topic. Will be discussed further in this topic. Looks good anyway.
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'90 Little Blue Truck, 2WD auto, FAS GenV 2.0 NA (AVH)

[dhaavers]

Wow, that is super clean, nigh pristine!

[Following edited for bad info…my apologies]
IIRC, there is a chart for oil amounts in Bentley, yes? I believe #10 hose is for high pressure, #8 for the low pressure side.
It’s been 10 years since my last AC project so I may have forgotten & of course this needs verification but it’ll also bump your thread.

- Dave
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86 White Wolfsburg Westy Weekender
"The WonderVan"
<EDITED TO PROTECT INNOCENT PIXELS>

[vanis13]

[AustinGoneWild]

One thing you can do to make things easy for you, is to remove your refrigerant hoses and take them to a local tubes and hoses type shop. They should be able to build new hoses with fittings. New hoses will contain refrigerant much better than the old R12 hoses.

Edit: also wanted to add that GW has replacement brackets. 255070124D is the part number.

[VicVan]

[MartinJS]

[MartinJS]

Sorry, just realized previous poster said hose and fittings shop, not AC shop. Mine I had made by local automotive AC shop.

[MarkWard]

Not sure if the compressors are similar, but using the TDI compressor I found adapters to convert the compressor to conventional AC hose ends. Probably in my notes.

I also had to modify the inside of the compressor to get compatible low pressure values to work with conventional expansion valves.

I also used R134. If you don’t have the equipment an AC shop can recover it if you need to change a component. Red Tek, you’re likely blowing it off into space. Ok if your ac works first swing, not if you find you need to modify the compressor. I’m not familiar with your compressor, but similar era.

Later compressors do away with the clutch completely. That’s another hill to conquer. I’ve not taken that on. I understand it’s solvable.

[wesitarz]

[VicVan]

[VicVan]

[VicVan]

[DeLvxe]

I am at the tail end of doing what you are doing: just finished putting the system together and about to pull a vacuum.

This is an all new system in a subaru swapped 1991 camper. I used EZ clips throughout, replaced the compressor, condenser, and receiver. Cleaned and reused the evaporator and expansion valve. I am working on a write up and parts list, but will add the draft to your post. The system will use 134a refrigerant.

About your oil question, the info is in the Bentley. If I remember correctly, it is 0.3 oz in each of the receiver, the high pressure hose, and the low pressure hose. The evaporator gets 5.something oz of oil. I used PAG 100. Feel free to DM me your phone number if you want to talk.

To get you started, here is my parts list and diagram of the system. Yours should be exactly the same with the exception of the connection to the compressor -- this wil depend on the location / orientation of your compressor, the specific adapters, and how you want to route the hoses.

I suggest you take all the hoses out -- go ahead and cut them to make it easier. Pay careful attention to hose routing and take some photos. you can take some measurments of the three sizes of hose (-6, -8, and -10), but you should be able to use the lengths in my parts list.

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1991 manual camper with EJ25

[Abscate]

The refrigerant dictates the oil type, not the compressor. Make sure you know what’s in the system before adding any oil.
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🇺🇸 🇺🇸 🇺🇸 🇺🇸 🇺🇸 🇺🇸 🇺🇸 🍊 🍊 🍊

[MartinJS]

[vanis13]

[VicVan]

DeLvxe! Wow! That is going to be so helpful. Thanks. It might be helpful to talk on the phone, when I'm further along.
Compressor: Is it the same model than the stock Subaru-provided one?
Hoses: you used the same sizes for the new hoses?
Fittings #8 and #9 on your list: what are these? where is the OEM port?

[dobryan]

[vanis13]