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Need advice: rebuilding the AC on my '91 Blazer

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smier

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I lost the serpentine belt a few years ago at 3 in the morning on my way to work, it took the electrical connectors right off the compressor and AC clutch assembly... I am heading to New Orleans this summer to help fill in for missions staff workers being pulled to begin reconstruction in Alabama and Joplin after the Tornados, I need AC again, it's normally in the high 90's and humid everyday... I can't take my Durango because the wife needs it to haul the kids, and my mustang just can't haul everything I need, so it looks like I'm taking a road trip in the blazer.
I know I need a new compressor and clutch, new lines, and evaporator. My question is, what else should I replace? We have the machine at work to purge the R12, but our mechanic isn't real familiar with the GM systems. I'm trying to do as much of this myself to save $$$. Any help is appreciated. So here's the start of my list...

1. Compressor and clutch assembly New $184
2. New evaporator
3. New lines
 
AC help

Well take it from me don't skimp on the compressor I put 3 of them in my 89 with in a year I was using Napa re-manufactred one, also don't do the conversion to the new coolent. recharging the ac isn't hard if you have a gauge and a good vac pump purge the system, flush the system replace the oil (off the top of my head I think it is 1.5 OZ of Oil but look it up) then add 2 to 2.5 pounds of r12 (look up the amount for your system it will be a on sticket under the hood or in the manual.
 
I'm planning on putting the newer refrigerant in( R-134A?). I had my '86 chevy pickup converted years ago, and it worked fine. Cost me $750 without a compressor though... Our mechanic at work told me he will help me on his own time for free, since I'm going as a volunteer, he told me to get all the parts I need together first. I'm not afraid to spend the money to do it right, just not sure of what to keep, and what to replace. This truck is going to be around for the long haul, so its worth it. A new compressor is only $35 more than the rebuilt, and I was told by our mechanic at work to avoid a rebuilt one also.
 
belezeebub said:
Well take it from me don't skimp on the compressor I put 3 of them in my 89 with in a year I was using Napa re-manufactred one, also don't do the conversion to the new coolent. recharging the ac isn't hard if you have a gauge and a good vac pump purge the system, flush the system replace the oil (off the top of my head I think it is 1.5 OZ of Oil but look it up) then add 2 to 2.5 pounds of r12 (look up the amount for your system it will be a on sticket under the hood or in the manual.
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It's not coolant, it's refrigerant. I don't think I'd listen to someone who doesn't carry any facts with him. R134 is not only more efficient, it's safer and MUCH less expensive. The spec for freon in my burb is right on the compressor. However, it's not hard to find out if you don't have that. Most systems do not operate at their peak at the exact spec provided from the factory.
 
I had my 83c10 converted to 134a and its colder than my buddys 07 chevy truck. Needed a new drier, orifice tube, and a low pressure valve if i remember right, and replaced all the seals. My ac guy said the new cross flow style condensers only lower the operating temperature of the system, not the vent temperature, and I trust his word on that. But if I needed a new condenser id buy one because its what the newer style trucks that run 134a use.
 
MaxPF had some upgrades for the crappy original AC setup including using a more modern Sanden style compressor. If you search you should find it. He lives in Arizona so he knows about heat.

Mine needs to be rebuilt so when I do I plan on completely upgrading the setup.
 
Confedneck said:
It's not coolant, it's refrigerant. I don't think I'd listen to someone who doesn't carry any facts with him. R134 is not only more efficient, it's safer and MUCH less expensive. The spec for freon in my burb is right on the compressor. However, it's not hard to find out if you don't have that. Most systems do not operate at their peak at the exact spec provided from the factory.
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I had a Good AC shop do the Conversion on my 89 using the stock style Compressor it lasted a month, before the compressor blew and sounded like a coffee grinder they replaced it once under warentee they claimed the R134 runs at higher pressure it blew again in two months got a full refund installed a napa compressor Boom replaced again Boom replaced everything and it finely held I was lucky the guy at the AC shop felt sorry and kept pulling the freon R12 /R134 out for free and putting it back in. never said 134 wasn't cheaper just said had problems with it in my 89
 
I was able to get a brand new Delco compressor from Amazon.com for my Burb, and it was less than the off-brand rebuilt ones from any of the major parts stores. It had the type and amount of oil to use printed in the instructions. It's certainly worth checking for your application.

Prematurely failed compressors have nothing at all to do with R12 versus R134a. Compressors fail because of:
1) Poor design, manufacturing process, or inferior internal parts
2) Moisture or debris in the system
3) Lack of lubrication or the wrong type of lubrication
 
The way it was explained to me, was the older R-12 style condensor does not flow well enough, or have enough passes in it's design to adequately cool the freon down, thus returning the freon back into the compressor at a higher temp than it should be, and also into the evaporator at a higher temp than it should be as well, in the long run, shortening the life of the compressor.

Also this affects the cooling of the air coming out of the vents, as the freon is not previously cooled enough, I have had these issues with my Burb here in Arizona. People in more mild climates may not have this issue.

Although at higher driving speeds, as long as there is constant higher speed airflow ofer the condensor, the system stays cooler, it's the stop & go traffic type driving that makes the AC into a swamp cooler.

Once replacing the condensor to the correct style to run 134-A, it cools the freon correctly, allowing the compressor to operate in it's normal temp range, and cooling more efficiently.

I haven't been able to see the difference in mine, as shortly after i installed everything brand new, except the compressor (which had already had several different types of freon through it) blew out a seal on the back side somewhere.

The system on my '94 Silverado is identical to the way i have it setup now, with 134 from the factory (the '94) and it gets and maintains nice cold temps out of the vents even during slow moving traffic situations.

I will always stand my by my theory that when converting from R-12 to 134-A, you SHOULD replace the condensor along with the orifice tube for maximum efficiency.
 
Change everything! Your system is 20 years old and will have some level of deterioration. You said you will be changing the compressor, evapoator, and hoses. All that is left is the condenser and accumulator.You will have the peace of mind with a brand new system. The acummulator is supposed to be changed every time you open the system and the condenser will need to be flushed. The older condensers are not designed for 134a, they will work but just not as well.
 
Yeah, I'm leaning towards changing everything. Something leaked and the system lost all the R12... The piece of mind is well worth the extra $200 to do it all. Anybody know of a replacement condenser that works in our trucks?
 
Anyone know why all the replacement AC lines that napa, autozone, advanced auto, etc., say they will fit suburbans with rear AC???? Will these work on a blazer, or are they only for suburbans? The parts monkeys don't have a clue...
 
Because four seasons has discontinued that part and only have the Suburban parts left in stock. The Suburban hose has an extra fitting that tee's off to the rear evaporator. It could work but you have to cap off one fitting somehow. Again, try LMC, They list it as part# 32-08729.
 
smier said:
Yeah, I'm leaning towards changing everything. Something leaked and the system lost all the R12... The piece of mind is well worth the extra $200 to do it all. Anybody know of a replacement condenser that works in our trucks?
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MaxPF's advice to me on condensers:
There is a drop-in replacement that is designed for R134a, but it's not a parallel flow unit. Instead, it is a "serpentine" style. It looks like a stock type condenser, but it has a larger number of smaller diameter tubes for more internal surface area. I have one on my truck right now. It works OK, but the parallel flow jobbies are still better. The air components guys can hook you up with a generic version, but it will mean different mounts and ends, and they may not be able to pre-make hoses for you (see my answer to your hose question). Thats not that big of a deal - they can sell you all the stuff to make your own hoses - you would just need to find someone local yo crimp them for you.
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Whoa!!! LMC is double the price on all the AC parts!!! Plus I have to pay shipping, and I'd have to wait... Maybe as a last resort.
 
I never said they had the best prices, but sometimes there the only one with the part you need. Like I said try Ebay, shop around, at least as a last resort you know were you can find the correct part. LMC is funny that way, sometimes the're cheaper on some parts other times the're more expensive, Never could understand why. But they are a good place to start.
 
I haven't looked, but try Rock Auto. They are usually about 1/3 to 1/2 the prices at Auto Zone, NAPA, and O'Reilly's. And shipping isn't too high on most items.

I just bought a new radiator for my 98 from Rock Auto and including shipping it was over a $100 cheaper than the same radiator at Auto Zone. Took three days to get it.
 
I just got off the phone with the four seasons tech department, those line sets that all the chain stores list won't work on a blazer, I guess I'll just replace everything else and either have new hoses crimped onto my old hardlines, or pay the $$$ for a set thru LMC when I blow one apart...
 
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