TheSamba.com :: View topic - Subaru/Vanagon A/C line adaptation question(s)

Fri May 03, 2013 8:08 am

So i've started to dig into my a/c conversion to the subaru compressor, and need some advice from those who have done it before

I have the original Subaru lines.

For the low pressure side i would like to adapt into the little metal piece that has the service fitting. (I would cut it so it just sticks out straight)

I noticed that the van line is bigger than the subaru line. If the shop were to add a length of hose between the subaru aluminum line and the van steel line can they make up for this difference?

For the high pressure side there is no removable piece to bring to the shop. Do i have to remove the entire hose from the condenser and bring it in? I am wondering if i can cut the little "disk" off the end and use a compression fitting? Can those hold 200+ lbs of pressure?

Also, as a side note, i noticed the line running from the drier to the evaporator (the one in the wheel well) was cut and spliced with a piece of tubing and clamped with hose clamps. The clamps appear to be a factory style clamp. Is this the way it cam from the factory or did someone make a repair to a damaged hose?

Thanks

Fri May 03, 2013 3:09 pm

Hey Brian:

The Subaru compressor, being from a 2005 model, was run on and designed for R134A refrigerant. The VW system was designed for and run on R12. These refrigerants use different compressor oils, PAG or Ester oil for the R134A systems, and mineral oil for the VW part. The oils are incompatible. If leftover mineral oil in your system mixes with PAG or Ester oil, it creates a sticky, gooey mess that does not properly lubricate the compressor.

Here's a fork in the road for you. It is possible to drain the oil out of the compressor, fill and drain it several times with mineral oil,and then leave the mineral oil in the rest of the system. BUT, you can only do this if you re-fill the system with R12 refrigerant, which is all but impossible to find at reasonable prices, OR if you use one or the hydrocarbon-based aftermarket refrigerants like RedTek.

Now, you can only use RedTek if you are doing the work yourself or know a tech willing to imperil his licence. Most AC and auto repair shops WILL NOT install anything other than R134A.

So, if you are doing this yourself, then you should use RedTek, since it operates at much lower head pressures than R134A.

The best approach, all around, is to replace all your hoses with new hoses. The R12 hoses are all quite old and quite leaky in most cases.

Regarding your hardlines, use the Subaru fittings that bolt to the Subaru compressor, and aluminum braze beadlock fittings to the ends after cutting off the Subaru hose fitting. There are many AC hose places that can take what you bring them and make up new hoses.

Regarding the jury-rigged hose near your AC receiver-drier, that is an accident waiting to happen and will be covered off if you get or make all-new hoses. You need to replace your receiver-drier, but don't open the new one nor install it until the last step in your work. They quickly absorb ambient moisture, which is the main function of the unit- - to absorb any moisture in the system to prevent ice forming in the expansion valve and blocking it.

Lastly, it is just normal maintenance to replace your expansion valve whenever the system is opened. You'll kick yourself if you don't since it is a $20 -$30 part and failure stops the system from working.

I made my own AC system from scratch (lots of fun) and ended up making some custom fittings and hose ends using aluminum brazing rods and a regular propane torch. Here's the link to my write-up:

http://www.thesamba.com/vw/forum/viewtopic.php?t=5...p;start=40

Try to post some pics of your Subie compressor and the fittings and I'll give you any hints I can think of.

Fri May 03, 2013 6:49 pm

Thanks Brian.
I was just about to ask the same questions

Mine is from 92 legacy 2.2. Were compressors in 92 all designed for r12?

Thanks

Fri May 03, 2013 9:42 pm

I have a case of es12a refrigerant, which from what i understand is just like red tek. It runs at the lower pressures, is compatible with all oil, and is really cheap (like $5 a can)

I plan on flushing/blowing out the whole van system with some air line drier and/or alcohol as recommended in some other threads. Then i will use PAG oil in the whole system.

I am going to take a chance and not replace the expansion valve. At $5.00 a can it's not the end of the world if i need to open the system up again to replace it.

As far as the lines are concerned, i tried to go down to Napa where they do hydraulic lines but they couldn't do what i need.

The problem is that the subaru lines are smaller. The low pressure side is 1.3 mm smaller than the vw low pressure pipe, and the subaru high pressure side is 0.7mm smaller. Subaru uses metric sizes and VW uses standard sizes.

Here's some measurements just for reference:
VW High side steel tube .5" (1/2) (12.7mm)
VW Low side steel tube .625" (5/8 ) (15.8mm)
Subaru high side aluminum tube .475" (12mm)
Subaru low side aluminum tube .57" (14.5mm)

I contacted a hose supplier in salt lake city about an hour from where i live. They can only get A/C hoses in standard sizes but they said they could use some sort of adapter on the subaru side to make it all work. I will take a ride down there tomorrow and see what they can do, and how they do it. I'll post all the parts they use, some pics, and the configuration i came up with when i get the chance.

Targis58,
your 92 is most likely r-12, so you are going to want to use a red tek type refrigerant as well. It is going to be a bit different than my 09, but i suspect you will also run into size differences.
There is a great write that i used as a reference that may help you as well. Click on the subaru engine 3 link. There is a tab on the page for how he did his a/c conversion. I think his is a 93 so yours would be similar if not identical.
http://www.weidefamily.net/vanagon/

Sat May 04, 2013 11:37 am

So i went to have the hoses made today. Here is what i ended up with:

so i cut the low side vw tube that had the service fitting so it went straight out, and installed a 5/8" compression fitting that crimps onto the hose. The other end they used a 14.5mm compression fitting to connect to the subaru low pressure hose. Done. overall length was 11" (this will be different for everyone depending on how much of the subaru line they keep)

The high pressure side i cut the little "disk" off exposing just a couple inches of the 1/2 inch steel tube. I used a 1/2 inch compression fitting to connect there, then to the new hose. On the Subaru side they used a 12 mm compression fitting on the aluminum subaru tube. Done. Overall length was 40" again, this may be different based on the subaru application.

overall cost was $100.

Wed May 08, 2013 5:31 pm

I just wanted to follow up with the a/c conversion. After installing all the new lines, flushing the system out with a quart of a/c flush, and installing the new receiver/drier i vacuumed it down and it seemed to hold pressure. I charged it with 3.5 cans of es12a and it works! I got 33 degrees out of the vents! I can practically make snow.

I am a little concerned, however, that my a/c compressor is not shutting off. Maybe an issue with the temp/ pressure sensor?

Sat May 11, 2013 2:47 pm

Very nicely done. I just had our a/c hooked up in a similar manner. I have a '88 wolfsburg with a 2.2 subaru engine.
I wasn't as brave as you and found a reliable ac shop that did the work for me. It wasn't cheap but they made the hoses, replaced the drier, filled the system and got it running.
I found myself with the dilema of sticking with r12, using redtek, or coverting everything to r134. Its a tricky call because there are advantages to doing each option. Luckily, I found some r12 on CL of all places, at a price less than R134. And there are still shops around the handle r12 without blinking an eye. It is my understanding that using r12 in an vehicle that was orginally made for r12 is still legal.. .
Anyways, nice post because I know for me the process of getting the ac hooked up and running was difficult and I even used a shop.
Although my wallet is much thinner now, I am looking forward to staying cool this summer.

Wed May 15, 2013 6:19 pm

Brianfromutah wrote: I just wanted to follow up with the a/c conversion. After installing all the new lines, flushing the system out with a quart of a/c flush, and installing the new receiver/drier i vacuumed it down and it seemed to hold pressure. I charged it with 3.5 cans of es12a and it works! I got 33 degrees out of the vents! I can practically make snow.

I am a little concerned, however, that my a/c compressor is not shutting off. Maybe an issue with the temp/ pressure sensor?

Hey Brian: Good to see the performance in your AC. To answer your question, let's start by asking what wires are connected to your compressor? The late subaru compressors, (at least some of them) are variable-displacement and have two terminals, one for the modulated current that controls the variable-displacement compressors, and one that powers on the compressor clutch. The VW factory system cycles the clutch off when the evaporator temp sensor reaches a certain temperature in order to avoid freezing the evaporator and also to allow the thermostat knob to adjust AC output temperature. The sensor feeds the info to an amplifier and the thermostat knob also feeds info to the amplifier which then powers on or off the relay supplying power to the compressor clutch. That relay could be damaged and stuck on. You might have the thermostat knob on maximum cooling. There may be a wiring problem between the temperature sensor at the evaporator. Start with those items and let us know how it goes.

Thu May 16, 2013 6:59 am

Howesight,

This is a very helpful thread and I appreciate you sharing your expertise on this topic.

:wink:
CJ

Thu May 16, 2013 7:48 pm

When i was getting 33 degrees out of the vents it was about 50 degrees outside air temp. Now that it is hotter out it closer to 45 degrees... good enough though.

The Subaru compressor is a one wire style.

Thu May 16, 2013 8:45 pm

Brianfromutah wrote: When i was getting 33 degrees out of the vents it was about 50 degrees outside air temp. Now that it is hotter out it closer to 45 degrees... good enough though.

The Subaru compressor is a one wire style.
My one wire Subaru compressor seems to be doing something similar.

I believe my compressor is from an R12 car, though unless in 93 - 94 they were using R134.....

I got 55 degree outlet temp with 85 degree inlet at 30- 50 psi low side and around 130 psi high side.

This is using 3 cans Redtek and one of their oil cans

I posted to the main Redtek thread.

I do not think this is quite normal.

Fri May 17, 2013 6:39 am

I don't remember what my pressures were. I think 30 on low is ok, but i think its supposed to be around 175 high. If your not getting enough pressure on the high side you may have an expansion valve that's letting too much refrigerant by.

Also, what rpm are you reading the pressures at? Try revving it to 2500 rpm and check what you are getting.

Mon Aug 19, 2013 1:51 pm

targis58 wrote: Thanks Brian.
I was just about to ask the same questions

Mine is from 92 legacy 2.2. Were compressors in 92 all designed for r12?

Thanks

This would be great to know.
thanks

Mon Aug 19, 2013 3:20 pm

there should be a label on the side of the compressor stating what it was intended for. All vehicle manufacturers were required to change to R134A in 1994, but some made the switch earlier.

Sat Apr 09, 2016 9:47 am

I am just at the point I need to do AC lines, Can someone advise me on what is the best path. I was considering buying a crimper and hose and making my own lines?

What is the most cost effective way method? If I buy a crimper there are three of use right now that can share the cost.

Sun Apr 10, 2016 11:07 pm

david2676 wrote: I am just at the point I need to do AC lines, Can someone advise me on what is the best path. I was considering buying a crimper and hose and making my own lines?

What is the most cost effective way method? If I buy a crimper there are three of use right now that can share the cost.

Go to the website for Nostalgic Air. Buy bulk barrier hose and standard aluminum beadlock fittings. Remove the original Volkswagen hoses from one van and use them as templates to make all your new hoses. It's worthwhile to upgrade to a modern parallel-flow condenser at the same time for improved efficiency. Nostalgic Air sells the 16" x 22" unit here:

http://nostalgicac.com/condensers.html

Here's is a good deal on a crimper:

http://www.amazon.com/Mastercool-71550-Black-Manual-Crimper/dp/B000WBQ4U2