Hey everyone, tried searching the forums but couldnt find exact answers so figured i'd ask. My 1987 US Testarossa is back from its engine out. I am handling recharging the AC. The system has been converted to R134. I have questions about two thing: 1. How much oil do I need to add? I didn't measure the oil I removed from the compressor, but I did drain it. I added 60 ml to the compressor based off of some research on other forums. I assume I do not add oil to the R134 charge and just add it to the compressor fill port, right? 2. R12 charge weight is 40 oz I believe, I was told 30 oz of R134 is appropriate for it. Does anyone have any insight into this? I plan on vacuuming the system tonight and maybe filling tomorrow. So any info or tips would be appreciated. Thank you
The oil for the compressor as well as the freon charge are both listed in the early pages of the owners manual. The freon charge is different for a US model. A always use R12 so I have no idea how much R134a. I looked it up. US TR holds 46 ounces R12. The hoses do not hold R 134 very well at all. I consider it a waste so I use the real thing. Did it have R12 or R134a prior to your service? If it had R12 (so easy to get and use in California many shops still use it) you need to replace the dryer and vigorously flush out the system or remaining oil will turn to goop.
The system was converted prior to my ownership. I will not be going back to R12 at this point. I will check my owners manual then. I do lose some charge over time, but for $20 I can top it up easily.
just note that the volume requirements between R12 and R134 are not 1:1...to get the same thermal efficient from R134, it needs more volume..which ends up running the system at a higher pressure.. I had a table somewhere that converts volumes between R12, R134 and Hydrocarbon based refrigerants.. the conversions they use, puts less R134 in the system, to keep the same pressure.. that results in less thermal efficiency from r134 in a R12 designed systems most aircon specialists should know this.
Does that mean someone actually changed the hoses that runs from the engine to the condenser, evaporator and the dryer? Not changing the hoses could very well be the source of the loss of charge, as R-134 has the ability to leak out of R-12 hoses. Considering the Testarossa probably has an easy 25 feet of hoses in the AC system, since the compressor is in the rear, the condenser in the front left hand corner. That's a LOT of hose. Theoretically the O-rings need to be changed at a minimum, a VERY challenging proposition at the evaporator. Chances are slim anybody did this in a conversion. Supposed to charge at about 90% of the volume of R-12. I would rather do an engine on one of these cars than change out the hoses. I can't see how the AC fittings can be snaked through the area in the center of the car. Almost seems like the hose would need to be pulled and then the fittings attached. Fortunately as long as your system isn't losing charge in a very short period of time, R-134 is still available and relatively cheap. When you start losing the AC in short order, then the real fun may begin.
No idea what was done, I had bought R12 replacement when I bought the car, never needed it. Then my shop said it had R134 and the fittings were converted. I used to have a supply of R12 when I had an old mercedes, paid $5 per 12 oz can, what a deal. Should have bough 50 of them. The AC works well, when its fully charged. So im not going to mess with it, just recharge it and add a can every year if needed. So for future info, it looks like 40 oz of R134A is needed in a Testarossa. I bought 3 12 oz cans, so ill see how 36 oz does and buy another can if needed. Couldn't fill the system tonight, need to buy a can tap apparently though I was told I didnt need to with the rental tool. But the system is holding vacuum, will check tomorrow. As for oil, I had added 60 ml of Pag oil to the compressor, I may add a splash more just in case it leaked out over time.
I bought TEN 30 lb jugs of Freon back in the nineties at Costco and just sat on it for several years. sold the last for 700 dollars and thought I hit a home run. Here I am 25 years later with only about ten pounds of R-12 and enough cars to use 15, and then I'm OUT!. Periodically I find a 12 or 14 ounce CAN on ebay for 35 bucks. While I kind of relied on watching what the vacuum did in the past, freon wasn't so hard to get. I'm going to invest in a nitrogen system soon. I have TOO many R-12 cars and too little R-12 to risk losing any in a leak. Same system can be used for heat pumps and other AC systems. If you rented a tool, chances are it was designed to be used with the 30 pound jugs and NOT the little cans, hence no can tap.
Yea I rented the tool, it will fit the small cans, but apparently the can type changed, so I now need a valve to open the can. The guy at Oreillys said I didnt need a tap even when I asked him. Oh well, this gives me more time to make sure the system isnt leaking. I wish I bought a 30 lb canister. But i'm fine with R134, its not as good as R12, but its less of a hassle to refill and work with. If my car was still R12 I would stick with it.
I think you know this, but you should pull a vacuum on the system first then charge. When I did the engine out on my Boxer I charged until there we no bubbles to be seen in the receiver dryer window. Has held 8 years - which for an old Ferrari is remarkable.
In the absence of R12, any reason not to use R12a which is compatible with R12/134a and has larger molecules and less likely to leak?
Honestly I have no idea. I have R134 fill ports on it and the oil in it is for R134. So that's why I'm sticking with R134. If I wanted to try R12a I'd probably have to change the ports, or get adaptors and change the dryer and flush the system Sent from my Pixel 7 Pro using Tapatalk
Does it? Haven't seen that on any of the diagrams for the AC or the fuel tanks. Have heard of that in the past but inline and not in the tank. Sent from my Pixel 7 Pro using Tapatalk
I still regularly use R12 and have yet to pay over 700 for 30 lbs of virgin R12. When I was in California it was easier to get and less expensive as an unintended consequence of their laws. I could make a call and have a pallet delivered before lunch. It is still in widespread use.
Since 1985. I dont make **** up. Look at table 57 of the 1990 parts book. 85 parts book doesn't show it but its a piece of crap and shouldn't be used. All the others show it. Who ever said it was inline?
Mentioned it because there was talk about the hoses possibly leaking. The 12a has larger molecules so lower pressure and less likely to leak. I put 12a into a R12 system (not the TR) and it works fine 3 years later. Didn't have to flush anything etc - that's one of the advantages Far as I know it's fully compatible with 134a. You might need an adapter for the can.
Never said you made it up, just asking for more info. I see it now, diagram 49 for 87 Testarossa part 57-58. I didn't say Testarossa had inline, I've seen inline stuff for other cars. Cools the fuel on its way to the engine, not in the tank. We should all have you order a pallet of R12 and everyone pitches in for a canister.
I was def. concerned about that also and read lots of arguments pro and against. But since R12 wasn't available and R12a was compatible without converting anything etc, went for it.
I'd be thrilled to buy another 30 pound jug for $700. I'm pretty good at finding things but I haven't seen ANY. Right now even R-134 is jumping in price and the cheapest I can find it for is $350.00.- up from around 120 from a couple of years ago. So a phone call and you can have a PALLET of virgin r-12 delivered below $700.00 a jug? Hard to believe. Can't even buy R-22 for anywhere close to $700 and it was in use until just a few years ago. The "evaporator" in the passenger side fuel tank can hardly qualify as one. A tube in and out of the tank. So when the AC is on, the fuel has a somewhat insignificant cooler, while the complexity of it seems hardly worth the bother. Two more locations with o-rings that should be changed if the car is running R-134.
Like these: https://www.autoacforum.com/viewtopic.php?t=13459 https://forums.tdiclub.com/index.php?threads/lets-talk-about-refridgerants-r-12a-or-r-134a.145180/
Right now a PALLET of R-134- forty jugs is almost 12 grand or $320.00 a jug. A person could buy a brand new car for what a pallet of R-12 would have to sell for. Something tells me Rifledrivers NOT going to buy all of us a pallet to divvy up without some serious money up front. I won't buy ANY R-12 substitutes that have been available. No point risking contaminating your system, putting some unknown substance, produced by unscrupulous dirtbags into your car.
