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87 elcamino v6 4.3 t.b.i.
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Discussion Starter · #21 ·
If you have even a couple of pounds of pressure, then that says there is still some R134a in the system, so you might get by without having to pull a vacuum. R134a is so cheap these days, it might be worth adding a few cans and see what happens. You should also add some leak dye at this point ( it will help you find a leak if there is one). You will need the gauges for this, as you will not know how much R134a by weight is left, and you normally charge by weight. Too much or too little will affect the performance, but you can get close by watching the gauges, and using a temp probe in the center vent of your dash. Trying to get to low pressure around 30, and high pressure about 2 to 2.2 times the ambient temp ( 80 degrees outside, high pressure 175 +/- 10%). Vent temps should approach 40 degrees. Charge with the revs about 1500 on the engine. make sure the radiator fan is in good working order.

If this doesn't work, and the dye doesn't show up a leak, then you are probably in for the full process as outlined above.
Extremely comprehensive and specific. I.d.k. how u know those numbers ,but I'm sure grateful. Next step , get guages,dye,134. Question? If I'm introducing 134 to low side as ive learned,how do I control high side pressure? Or are your figures what a properly functioning system has on hi side after @ 30 p.s.I. on low side?
 

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You don't really control the high pressure side so much as monitor both high and low sides with gauges and compare them to an R134A Temperature vs Pressure chart that is widely available on the webs.

Yes, you should fill by weight but this chart and the gauges are a good diagnostic tool.

Rick

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87 elcamino v6 4.3 t.b.i.
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Discussion Starter · #24 ·
Thanks that will make the numbers easy
(Cheat sheet) . with y'all help,I feel confident to tackle the A.C.system now. Much obliged... I look forward to posting outcome from all these posts from my dist distributor problem to trans and a.c. ! I only hope I can pay forward the kindness to another elcamino lover ,that everyone has shown me here.
 

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Wouldn't it be still better to vacuum the system ? I just talked to my buddy that is a a/c guy and he sure recommends it.
 

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You need to get the moisture out ! You also need to know you have the correct amount of oil in the system. May be wise to let someone that already has the knowledge and equip. to do it to get it right. Not saying you can't do it but you could ruin a compressor if its not dry.
 

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Wouldn't it be still better to vacuum the system ? I just talked to my buddy that is a a/c guy and he sure recommends it.
Always better, if you have the equipment. Theoretically, if it was done properly last time when it was charged, and there is still freon in the system, then there would not yet be any moisture intrusion. But you never know how the last guy did it. He may have just stuck in some R134a in a dry system...

My suggestions above were a "quick and dirty" way to see if there was a leak, and to try and find it via the dye.
 

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87 elcamino v6 4.3 t.b.i.
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Discussion Starter · #29 ·
Always better, if you have the equipment. Theoretically, if it was done properly last time when it was charged, and there is still freon in the system, then there would not yet be any moisture intrusion. But you never know how the last guy did it. He may have just stuck in some R134a in a dry system...

My suggestions above were a "quick and dirty" way to see if there was a leak, and to try and find it via the dye.
I agreec100% for all the time and labor involved I think it's just cheaper for me to take it to an AC shop and specify specifically what is going on, and what I want. Off-topic, I have the opportunity to buy a case of R12 12 oz cans 10 of them. This is original stuff from an OG El Camino lover who is retiring from the scene. Do you think it is worth purchasing? I know I can't use it, but can spread around to people who need it in my area? He's giving it to me very cheap half the price that each can is selling for so if I did sell I would make double profit
 

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I have 87 elk with v6 all stock/orig. Tired of Not being able to use car when it's hot outside! So I want to fix my a.c. but don't know where to even start. .lucky that all my components are intact/orig. I know the system has No pressure,but little else. When I discuss with other g.m. classics owners,I get mixed advice. Some say just get it converted at shop,its not worth headache. Others say keep original,do it yourself,or take to shop,but still keep original,as its easier/cheaper to stay with r-12. And that the hardest part is finding someone who is familiar with r-12,and finding the r-12 itself . so I recently had the opportunity to buy some r-12 cheap, thanks to old member retiring from the scene. And his advice was stay r-12 as the conversion req everything except evap to be changed. (Even hoses as 134-a leaks due to being smaller atoms) . So where do I start to determine r-12 or conversion? How can I tell if it has r-12 or 134 in it now? How do I test comp? Ive turned on a.c. but comp doesent seem to engage,guess I will have to learn the circuit and test. I read other forums about this subject ,but they are always incomplete. Any advice /personal experience\ or threads to follow appreciated.
SAFE DRIVING.
Recently I took my 81 to the garage to get converted from r12 to r134a. There used to be a shortage of 12 but now the salvage yards have to suck it out of the systems and fewer people use it so it's around. Still hard on ozone layer. Anyway, the garage sucked out the old stuff and put in a new dryer, oil and recharged it. Well, it works fine but occasionally the compressor clutch starts screaming on me. Wish I had changed that (whole compressor w/clutch unit) out myself with a rebuilt unit after the old r12 was sucked out. Anyway, it works but might require a compressor replacement at some point. I rebuilt a 66 corvette a/c system once by replacing every rubber 'o' ring seal. Wouldn't do that again because there are leak dyes that help find issues without doing unnecessary work. If it hasn't been used in many a moon you might want to follow my compressor and dryer replacement recommendation the first time.
 

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I agree with VinnyD. I have a 83SS 350 (305) with a converted system with stock components. It works quite well. I am in Phoenix Arizona and it gets HOT down here also. I did also replace the orifice tube that my mobile mechanic broke while trying to remove it.
 

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I've been using the Enviro-Safe Industrial refrigerant in my vehicles for over 20 years. It works great in both R134a and R-12 systems and doesn't react to moisture if it gets into the system like R-12 does. Its also compatible with mineral oil and PAG oil so you don't need to flush out the system unless you want to. In addition, it runs at a lower pressure in the system which frees up horsepower and increases mileage. It runs about $7 a can and you don't need a license. Been running it in my 87 El Camino for about a year and a half and blows 40 degrees at idle when its 90 degrees & 90% humidity. It's a very good option for upgrading your a/c system.


Head Vertebrate Liquid Drink Fluid
 

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I completely rebuilt the system on my '78 Monte Carlo, which is exactly the same as my '79 El Camino. I replaced EVERYTHING with a line connection and then replaced the electrical components; fan, relay, pressure switch. I checked all of my vacuum line connections and diaphragms. I filled the new compressor with 8 oz PAG 150 oil, put 2 oz of PAG 150 in the Receiver/Drier, all new seals, pulled the vacuum with a pump, let it hold for an hour with no leak-down, added total of 30 oz of R134 and it cools at 50 to 55 degrees.
Some parts are hard to find. I had to order the condenser from California for $350
My total labor time was about 10 hours at a cost of approximately $1200 in parts. That's why a shop will probably charge $2400 - to $3000 to do it right. This system should work for well for a good 10 years without any other attention.
 
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