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Discussion Starter · #1 ·
I just ordered a Robinair vacuum pump (already have manifold gauges) and I am going to convert to R134a in my 91 L. I will need to order a 134a expansion valve for a 94 - 95 model and a receiver dryer, which I understand is the same for R12 or R134a, right? I am going to save money for now and use the original condensor and see how it does. Crossing my fingers that my compressor is good, which it should be. The last time I had it off the car, I emptied it of the old oil and put in Ester oil in preparation for the R134a. The manual said to fill it to 70% of capacity, if I remember right, which I did. The low side valve is very close to the hood, so I guess I will have to use a 90 degree R134a adapter? Anybody know what size adapter I need for the high side? Thanks, I have been driving home in 103*F weather (my ext temp on my console went up to 111*F one day!) and I am feed up! :eek: Oh, and I will replace my seals with the green ones.
Charles
 

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Discussion Starter · #2 · (Edited)
How well will this work with the original expansion valve? Maybe I should just buy a set of A/C hoses from a '94-'95 from APE? Will they bolt right in and make for the utimate retrofit job?
Charles
 

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Discussion Starter · #5 · (Edited)
What is a good flushing system/method? I thought dryers were refrig. specific as well, but I only see vendors selling one, or do I buy one for a '94-'95 model? Thanks for the tip on the Nylog. ;) By POA you mean expansion valve? Can I have my old hoses converted to R134a at a hose supply? Gosh I'm full of Q's.
Charles
 

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Discussion Starter · #7 ·
Do you sell the R134a POA valve? I haven't seen it listed with any vendors. Thanks for your tips! The only other A/C work I have done was converting my old 190E years ago to R134a and it colded down plenty well with no new parts but a new compressor!
Charles
 

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Discussion Starter · #9 · (Edited)
I found this website interesting on the retrofit. http://www.epa.gov/ozone/title6/609/oneshop.html At the bottom of the page it says "Imports" and talks about adjusting the POA valve adjustment screw one quarter turn counter-clockwise, but this may be for a Toyota or Nissan. I think the cardisc calls the P.O.A. valve an E.P.R. valve? Don't see where you would adjust this thing?
Charles
 

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Discussion Starter · #11 · (Edited)
I thought Ester Oil was the preferred oil to use when doing a retrofit? I assume when all mineral oil has been removed or almost the whole system is new and the rest is thoroughly flushed, PAG oil could be used like in a standard R134a system? I assume the Ester oil I added to the compressor (70% of the compressor capacity) is ALL the oil I need to add for the WHOLE system?
Charles
 

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Discussion Starter · #22 · (Edited)
So the original R12 Freon charge is 44 oz. Sanden says ~ 5% less by weight for R134a. So if I do the math: 2.76 lbs - 0.138 lbs = 2.622 lbs X 16 oz/lb = 41.952 oz of R134a. Let's just say ~ 42 oz. Also Sanden is calling for 4.6 +/- 0.5 oz of PAG oil, so I assume that is for the whole system?
Charles
 

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Discussion Starter · #25 ·
Yeah, I doubt I can really flush this system myself very well and I already have the compressor filled with Ester oil. So I leaning towards leaving it since everything I have read leads me to believe that it will behave itself along with the old oil that is in the rest of the system. It may not be the BEST thing for the compressor but...I think it will work.
Charles
 

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Discussion Starter · #30 ·
Sure, I'm still getting it all together though, and trying to figure out my options. One could spend a heap and one could spend very little, but one system would cool for years and the other would probably cool for all of a week before things went downhill. So that is the difference. I am trying to make good decisions for a long lasting system, but for reasonable money.
Charles
 

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Discussion Starter · #32 ·
Could I use a used POA valve from a 24V car and the hose from the POA valve to the compressor? I found a site that describes how to calibrate an R12 POA Valve to R134: http://www.autoacforum.com/messageview.cfm?catid=20&threadid=7567 should work on the 164 as well, but now I need an air compressor too or an air tank at the very least. :(
Charles
 

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Discussion Starter · #35 · (Edited)
You can use the POA from a 24V, no problem. The hose may be an issue. It is a hard line that is bend to fit around the alternator.
Just takes yours to a A/C place and have them make one using your fittings, maybe $30?
All the rest you can use from the 24v.
That is the only hose that's an issue.

Just get as much from a 24V as possible, if you like I can try to get some of the parts for you? I have a POA valve here that I can calibrate if needed. I can have AMA do it.

Jason
I think the POA valve set to something like 26-27 psi is the real secret to getting cold air from a retrofit job (obviously, I no expert but learning as I go). I will call you Monday about the items I need. :D If you can get these 24V hoses together for me that would be great. ;)
Charles
 

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Discussion Starter · #36 · (Edited)
OK, here's the plan. I have ordered a '94-'95 POA valve from APE which should be properly calibrated for R134. Expansion valve and receiver dryer ordered from Jason (Alfissimo). I'm going to use my old hoses which shouldn't leak too much R134 (since it has smaller molecules) over the course of a year or so and it is cheap enough to not justify the cost of changing them right now for me. IMHO. The black stuff to insulated the expansion valve bulb is called Prestite, comes in a tape form and turns into the black amorphous goop you see around the expansion valve bulb, A.K.A. "Monkey Doo" apparently. :D
Charles
 

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Discussion Starter · #37 · (Edited)
Got the system working last night after much effort getting all the items together that I needed. Jason got my parts out to me same day even though he was taking off for vacation, but the vacuum pump needed to be converted to work with R134 gauges and various other items I needed like a POA valve for 134 from APE from a '94 (they sent that pretty quick too). Swapped parts, Vac'ed and charged it last night and got it down to ~42*F at the center vent, on fan setting 3 and recirc turned on. I may need to put a little more 134 in, but I will see how it works on a hot day as is. :D O, FYI, those little O-ring kits from the auto parts store, contain very few O-rings that fit the 164. Also, the black "Monkey doo" insulation goop is reusable, just pull it apart like silly puddy, make a strip off it and rewrap it around the pipes, it looks like new and starts to stick to your fingers very well after working with it for a bit.
Charles
 

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Discussion Starter · #39 ·
Recirc turns off Auto mode (actually both mode lights go out), is it doing what it is supposed to? It has been a long time since this car had A/C.
Charles
 

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Discussion Starter · #42 ·
I got my A/C parts from Jason. Expansion Valve, Receiver/Dryer. POA valve from Alfa Parts Exchange. I was able to replace some of the seals from the auto parts store seal kit, but some I had to reuse because the kit didn't have the size in it and they were in good shape. I would guess Alfa has a seal kit? Might want to inquire from Jason about that before you get into it deap. ;) Vacuum pump from eBay, new SPX/Robinair, model 15600 and Acme inlet adapter #15495. My compressor was apparently still good. :D The old Expansion valve was plugged up at the screen. I have been busy plugging the hole in the false firewall at the point where the hard A/C line goes through on the rightside of the engine compartment. That is the side where the air is taken in from and I suspect a LOT of hot air can get sucked in to the A/C intake there if it is not sealed up good. HVAC silver aluminum tape works great patching up the F/F as well. Also noticing my A/C filter needs replaced. :eek: Has anyone come up with a good way to keep dirt out of the air intake? I'm thinking of cutting a piece of the very course blue fiberglass HVAC filter material to cover the top of the air intake to keep the very big stuff like leaves out of the air intake before they even get to the cabin filter, seems like it would be a good solution.
Charles
 

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Discussion Starter · #46 ·
Makes good since, when you put it like that. I have not done the research on it. ;) I just hope all the "old" cars can be made to use the new refrigerant, easy enough.
Charles
 
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