spedy7

Hello again! I've been doing some research to eventually get my a/c working again and keep finding conflicting answers. Currently have the original r-12 system, but being Arizona, I'd like to get it working again so driving is more tolerable. For me, R-12 is kinda out of the picture due to price and low availability and it isn't going to be a garage queen (it'll be a daily once I get it registered). I've heard mixed results from moving to 134a: One thing I've seen is needing to change out the condenser for a parallel flow one - if that's the case, any recommendations? If the old condenser is fine, would one or two small pusher electric fans help bring down the pressures to normal? Blended refrigerant is also out of the picture, and I'm a bit skeptical with 152 and any propane/butane refrigerant as well. Doesn't get really humid here unless it's monsoon season, so that's a bit of a plus for 134 systems. Wouldn't be expecting new car 40* vent temps, but something cooler than 110 in the dead of summer would be fantastic.

R-12 systems are also alien to me, never worked on one. Installed a complete under dash system (not retrofit) on my Mustang not too long ago and that works fantastic....until the temp goes past 220 on a hot day (a/c still stays at ~35* though lol). I have done a/c work at my past job too, but we didn't have the equipment for R-12 and never did any retrofitting. It's a GSL-SE if that matters too, still trying to learn more about these cars :P.

Qingdao

iTrader: (3)

134 works but 152 is best. Isn't 1234 propane as well? There isn't any O2 in an ac line or source of ignition so I don't see the problem. I mean you have just as much of a chance of the fuel from your gas tank burning up under the hood.

I use the clutch fan and I don't seem to have an issue, but the ac does work better at speed so I'm sure a pusher fan wouldn't hurt. I spend most of my time moving, not much stop and go.

The GSLSE has a factory unit if i'm not mistaken. What kind of connection does your condenser use? The dealer installed sanden unit has hose clamps LOL

DreamInRotary

iTrader: (49)

I've done R152-a in multiple cars now and they all work excellently. I believe that you could do the same in the FB without issue, so long as your components are still good and don't have leaks.

t_g_farrell

iTrader: (1)

+1 on 152a. Its cheaper and even better for the environment and has almost the same cooling characteristics as R12, so no need for extra large condenser. I've done it on 3 cars in the past and they all worked great for years (+5). I'll be doing my F150 and the 7 soon (need to get my AC back in the 7).

Toruki

I had an R134a conversion done a few years ago. Can confirm it cools less efficiently than R12 but enough for my area, Boston, MA. No leaks from what I can tell. 83 with Sanden compressor.

Sgt Fox

iTrader: (3)

I used R-152a myself, but given that you are in the US, you can buy cans of R12 pretty cheap off eBay (~$30 a can)

Zener_1

I did a R134a conversion on my SE back in 1998.

Works great and super easy to get the 134a when you need to top off <$5/can at wally world) - and you will - the hoses used in r12 systems do seep the 134a molecules a bit. You must replace the accumulator because the desiccant in R12 systems aren't compatible with R134a. Ironically the better you flush the old oil out of the system, the worse the hoses seep the new refrigerant. I think the old mineral oil residue helps the hoses not to seep as much. That said, you need to get as much of the old oil out as reasonably possible. Dump the old oil from the compressor for sure. I used POE type oil rather than the more widely available PAG because PAG is incompatible with the residual mineral oil in the system.

As a fellow hot climate dweller, I can assure you that you MUST have a pusher fan on the condenser. Measure the height of the condenser coil and get the biggest one you can find that will fit that dimension. I switch the pusher using a relay triggered by the compressor clutch. Clutch engages, pusher on.

spedy7

Yep, 1234 is propane from what I've read. Not trained on it, but briefly learned about a couple of its unique features (besides needing equipment that costs twice as much as 134 equipment). Don't know what compressor is on there or what connections it has, but it is the original compressor. Last I saw, the SE has a factory installed system (don't know the difference between the two).

This is what I've found from previous topics from quite a few years ago. Was hoping something better came up for anyone using 134, but I guess not. All 152 is is the electronics dust cans right? Would anyone know how much it takes too?

Is there any place to get new hoses or would I have to have them custom made? I think the high side hose may be leaking too, but haven't checked for leaks yet. Ester/POE oil mixes fine with mineral oil too?

Qingdao

iTrader: (3)

1234 is wild. The pressure :O


Keyboard duster... that's right. I used about 600 grams on my sanden system. I'm sure the GSLSE probably has close to if not the same capacity.


I re-made my hoses. I bought the line crimp tool (a shocking $250 tool for a one time use). And a line kit for another 100 bucks. And I don't have to worry about seepage or old oil impregnated in the hoses. I guess I can make power steering hoses and other stuff with the tool but damn its not cheap.

t_g_farrell

iTrader: (1)

Takes about 2 cans for most systems. I just add until the temp gets to max lowest and the pressure is within specs. It goes on sale at Staples all the time for like 3 cans for $10 or something. Its the cheapest alternative you can find and works really well.

You will need to have those hoses made for you and depending your system it may be a challenge to get the right metric ends on them. If they can reuse your original connectors that is a big win.

Zener_1

According to my records, my SE took 8 oz (fluid measure) of POE and 30 oz (weight) R134a.

As a minimum guess I'd capture all I could of the old oil and measure it. Add that much plus 1 ounce of the new oil (figure at least that much in the accumulator?). POE and the mineral oil are compatible. I've been told POE can form acidic residues if it there is too much moisture in the system so evacuate the system well before charging.

I suppose its possible someone like Rockauto might have the hoses, but if it were me I'd take the old ones to a hose shop and have new ones made if needed, reusing the old fittings. On empty systems, I check for leaks by pressurizing it with 100+ psi compressed air and spraying all connections and hoses with a soapy solution. You can find most leaks cheaply that way.

Qingdao

iTrader: (3)

Never thought about checking for leaks that way... Makes sense. I was always told to pull a vacuum on it and let it sit; if the vacuum holds then you are good to go.

For the record I used ester oil in my system, but I don't know exactly what oil 152 likes or doesn't like.

Zener_1

Yeah much faster finding leaks in a system with pressure versus vacuum. I still do the vacuum hold test after I think I got them all. Made a hose to connect my compressor to standard AC fittings. Can dial in pressure I want and maintain it while leak seeking.

chuyler1

iTrader: (1)

My system passed the vacuum test with flying colors, had it refilled with R134a since it was converted in the 90s. Lasted 4 weeks of moderate New England weather. Heat wave 90+ degree humid day stuck in traffic it conked out. Had it tested again, they couldn't find leaks. I gave up and removed the whole system. Saved everything so maybe I'll make lines and reinstall some other time...but for now, because race car, I'm saving a ton of weight. That compressor bracket would make a great boat anchor by itself.

Ckforker

I used 134, had new hoses made up and painstakingly cleaned the condenser of all debris. You will also need to switch all the o-rings to be compatible with your refrigerant. Mine has been amazing for about 4 years now, but it doesn't get too hot here in the mid-Atlantic area, at least not like home in AZ.

Pete_89T2

iTrader: (4)

Another +1 on the R-152a/HFC-152a refrigerant choice (aka - computer duster gas, about $11 for a 4-pack of 10oz cans at Walmart). I've been running that in my FC for 2 summers now, cools the cabin just as good as the R12 did. When I charged mine with the R152a, I was restoring the system from an AC compressor failure (it seized). So I took the entire system apart, flushed the condenser, evaporator core and all hard/soft lines to clean then of all old R12 lube & potential failed compressor bits. Bench flushed & lubed the new compressor with Ester 100 lube (compatible w/R134 and R152a) to the FSM recommended capacity (about 80cc, IIRC), and when I rebuilt the system I used all new O-rings (the green HBNR types are compatible w/R134 and R152a), and installed a new receiver/dryer and a new expansion valve (R12 type - OEM replacement). Evacuated it, and verified that it held vacuum overnight, then charged it with almost 20 oz of R152 (just shy of 2x 10oz cans).

spedy7

Well, I guess 152 is the better option. Don't want to blow out a line or trash the compressor with 134's pressures. What should I be looking for pressure-wise for a R-12/152 system?

Also, thanks to everyone for your input! Didn't know keyboard duster was a popular conversion choice!

t_g_farrell

iTrader: (1)

Basically you follow the same guidelines as used for R12, its very similar to R12 characteristics.