How cold should it blow? [Archive] - El Camino Central Forum : Chevrolet El Camino Forums

: How cold should it blow?


cubegleamer
06-18-2010, 09:47 PM
I just dropped $700 getting my A/C fixed. How cold should it be blowing? My wife has a 2010 car and the air blows so hard and cold that it almost hurts. What temp should it be blowing and how do I check it? I don't want to spend $700 on an A/C that isn't working at it's full potential.

lsrx101
06-19-2010, 01:48 AM
I just dropped $700 getting my A/C fixed. How cold should it be blowing? My wife has a 2010 car and the air blows so hard and cold that it almost hurts. What temp should it be blowing and how do I check it? I don't want to spend $700 on an A/C that isn't working at it's full potential.


Well,
Make, Model, Year, and specifics about the recent repair would certainly help.
If it's actually "cooling", temp readings and manifold gauge readings couldn't hurt either.

darbysan
06-19-2010, 07:50 AM
Pick up an AC thermometer at the auto parts store- they are not expensive. Stick it in your outlets, and run on Med speed. For me, I see temps get as low as 26 degrees, but anything between 35-42 is pretty good. This is with the car moving, and the Outside Air Temp below 90. Any higher OAT, and the numbers might go up a couple of degrees.

Our fans do not move as much air as the newer cars. On High, mine is about the same as Medium on my wife's Toyota. But with the small cab, it shouldn't take too long to get down to temp.

cubegleamer
06-19-2010, 11:33 AM
Well,
Make, Model, Year, and specifics about the recent repair would certainly help.
If it's actually "cooling", temp readings and manifold gauge readings couldn't hurt either.

It's a 1972 Chevrolet El Camino
350 automatic
Here's what I've had done:
New A/C Compressor
New A/C Accumulator & Orfice
New Receiver Dryer
OZS R134A & Oil

It seems to blow fine but It just isn't that cold. Sometimes it feels like it's fluctuating in temp. Blows cool air then warm for a few seconds... then cool again

I'll pick up a thermometer at a parts store today and post an accurate reading of the temp.

I just don't think it's getting anywhere near 35-42 degrees.

Let me know if there is anything I else I can tell you or any photos you might want me to post.
Thanks for the help.



http://img.photobucket.com/albums/v389/cubegleamer305/Elky/72newcompressor.jpg

http://img.photobucket.com/albums/v389/cubegleamer305/Elky/72ac2.jpg

ssr71
06-19-2010, 02:29 PM
It's a 1972 Chevrolet El Camino
350 automatic
Here's what I've had done:
New A/C Compressor
New A/C Accumulator & Orfice
New Receiver Dryer
OZS R134A & Oil

It seems to blow fine but It just isn't that cold. Sometimes it feels like it's fluctuating in temp. Blows cool air then warm for a few seconds... then cool again

I'll pick up a thermometer at a parts store today and post an accurate reading of the temp.

I just don't think it's getting anywhere near 35-42 degrees.

Let me know if there is anything I else I can tell you or any photos you might want me to post.
Thanks for the help.


Your system has really been modified! Not saying this won't work... I only know enough to understand the mechanics to a degree.

darbysan
06-19-2010, 02:50 PM
On the surface, it sounds like your compressor is cycling on and off. If this is so, it could be becasue the Low Pressure switch was not adjusted when converted to R134a, or it may be low on R134a. We'll know more when you get the temp readings.

When the car is sitting in the driveway, turn the AC on Max and High Fan. The compressor should come on and stay on for maybe 45-60 seconds or longer, trip off for 10 seconds or so, and then come back on. If is is coming on in short spurts, then one of the two things above could be wrong.

Also, make sure your Heat control is all the way to cold. Sometimes, Hot water can be circulated through the core and mix with the AC. This is pretty remote, though.

cjlaketexoma
06-19-2010, 04:25 PM
Hey Darbysan, could you describe the setting of the Low Pressure switch process for an R-12 to 134a conversion process please? I'm probably just being senile, no doubt it's on the other threads I've read on this topic, but hey, while we're all here... Thanks!!

Oh, and in preparation for this deal, I've already followed a friends advise and put in a water cut-off switch on my heater hose, he has trouble with his late-60's stuff leaking heat into the ducts, you know all that stuff under there is just not as tight as it was day-1. cubegleamer, I'd recommend you do the same, just to keep that extra heat outta the cabin. I immediately noticed how much nicer it's been tooling around in my beater just with that cutoff switch installed.

darbysan
06-19-2010, 06:26 PM
I don't know if it's the same for a '72 as it was for my 5th Gen, but there is a switch that is part of the accumulator. Should have two wires going to it. If you remove the connector, there will be a small screw in the switch between the two connector prongs on the accumulator side. Turn that screw while the AC is on. I think it is clockwise. Turn until you get a longer on period. How long is subjective, but I've seen mine run for minutes at a time before it takes a break. If your accumulator is getting frosty, then it is running too long. If turning that screw does not improve the performance, return it to it's original position ( count the turns) and take it back to the AC shop. At that point my guess would be low on R134a, and maybe there is a leak.

lsrx101
06-19-2010, 07:04 PM
That system has been very modified. I see an accumulator has been installed in place of the POA valve and it sounds like maybe an orifice tube has replaced the expansion valve.
I can't tell by the pics, was an orifice tube added or does it still have an expansion valve? It looks like the TXV might be there in the second pic. It would be connected to the bottom port on the evaporator and the line from the condenser would be connected to it. The top is round and looks kind of like a flying saucer.
If the TXV is still in place, the system will not work properly with that new accumulator.
Is there still a receiver/dryer up in front of the condenser?

pongo
06-19-2010, 07:31 PM
I know for a fact that not all systems that are designed for R-12 will cool on R134A. When you replace the old R-12 parts with new parts, these new replacement parts are still made to R-12 specs. I have tried to do several old cars and nothing I do will get them to cool well on 134a, so I fill the system with oil for R-12 and fill the system with propane and they cool like crazy. My 78 Elky is cooling on propane and is so cold it hurts. I know what evertbody is thinking, a big propane bomb under my hood, but there is not that much propane used to charge a system, and you are carrying why more gas that is way more explosvie than propane

cubegleamer
06-19-2010, 08:47 PM
I'm new at this and I appreciate your patience and guidance with this.

I bought an A/C thermometer and drove the car home from work at 10pm with the A/C cranked all the way up. It's a 10 minute drive and the temp never reached 60.

I'm compiling a list to ask the mechanic that worked on my A/C. If anyone has any input please let me know. So far I have:

1. Was the low pressure switch on the Accumulator adjusted when converted to R134a?
2. Was there an accumulator installed in place of the POA valve?
3. Was the Expansion Valve replaced with an Orifice Tube?
4. Is the TXV still there? If so, why is it there with the new accumulator?

lsrx101, Is this the TXV in the photo below?

http://img.photobucket.com/albums/v389/cubegleamer305/Elky/C3.jpghttp://img.photobucket.com/albums/v389/cubegleamer305/Elky/C4.jpghttp://img.photobucket.com/albums/v389/cubegleamer305/Elky/C5.jpg

lsrx101
06-19-2010, 10:48 PM
I know for a fact that not all systems that are designed for R-12 will cool on R134A. When you replace the old R-12 parts with new parts, these new replacement parts are still made to R-12 specs. I have tried to do several old cars and nothing I do will get them to cool well on 134a, so I fill the system with oil for R-12 and fill the system with propane and they cool like crazy. My 78 Elky is cooling on propane and is so cold it hurts. I know what evertbody is thinking, a big propane bomb under my hood, but there is not that much propane used to charge a system, and you are carrying why more gas that is way more explosvie than propane

Just don't let your insurance company know.

The main difference between the gas in your fuel system and the propane in your AC system is that the gas never enters the passenger compartment. The evaporator is IN the passenger compartment under the instrument panel. Evaporators very often leak. It's not an explosion under the hood that's the problem.

Except for a few vehicles with marginal R12 AC systems to begin with, R134a conversions can work just as well as R12. You obviously just don't know how to do it.

lsrx101
06-19-2010, 11:23 PM
I'm new at this and I appreciate your patience and guidance with this.

I bought an A/C thermometer and drove the car home from work at 10pm with the A/C cranked all the way up. It's a 10 minute drive and the temp never reached 60.

I'm compiling a list to ask the mechanic that worked on my A/C. If anyone has any input please let me know. So far I have:

1. Was the low pressure switch on the Accumulator adjusted when converted to R134a?
2. Was there an accumulator installed in place of the POA valve?
3. Was the Expansion Valve replaced with an Orifice Tube?
4. Is the TXV still there? If so, why is it there with the new accumulator?

lsrx101, Is this the TXV in the photo below?



I can't see the evaporator inlet tube in the pics so I can't be sure. What I thought might be the TXV looks like the compressor thermostat. It could be the part in the shadow just below the thermostat (the little square box with the wires on it).
I can't figure out why someone would remove the POA valve and install an accumulator (the big silver can). They are 2 totally different components and have nothing in common. That's just bizarre.
Here's a POA valve:
http://www.classicautoair.com/thumbs/170/VALVE-POAValveAfter15-51%28type-2%29.jpg



http://img.photobucket.com/albums/v389/cubegleamer305/Elky/72ac2.jpg
Can you get a close up pic of the part that the red hose is connected to in this picture? That's a High Side service hose, but there shouldn't be a port to attach it to in that area.
I hate to say it but unless I'm really missing something, it looks like someone just totally hacked up your system.

cubegleamer
06-20-2010, 08:53 AM
http://img.photobucket.com/albums/v389/cubegleamer305/Elky/C6.jpgHere's a close up.

cubegleamer
06-20-2010, 09:48 AM
I just did a search for 72 El Caminos on eBay to see if I could get an idea of what my A/C should look like. This is what I found.
http://img.photobucket.com/albums/v389/cubegleamer305/Elky/ebayac1.jpg
Here's a shot of mine:
http://img.photobucket.com/albums/v389/cubegleamer305/Elky/72ac2.jpg






I'm going to take it back to the shop on tomorrow and have them remove the accumulator and install a POA valve. Can you tell from my photos if anything else has been hacked up?

darbysan
06-20-2010, 09:48 AM
I know for a fact that not all systems that are designed for R-12 will cool on R134A.

FYI, I just replaced all my components and went with R134a. It is a gen 5 car, and that may be a difference, as it has an orfice. The replacement compressor was marked for r12/r134a usage, as were the hoses. I saw 26 degrees out the vent last week ( 90 degree OAT). I typically run 32-40 with no issues, with OAT at or over 100. In fact, I think 26 is too cold- may freeze up the evaporator.

darbysan
06-20-2010, 09:52 AM
Found this article on converting to R134a on older GM cars. Has some pictures, and may be helpful.
http://www.classicautoair.com/GM_OEM_Parts_134A_Conversion.html

cjlaketexoma
06-20-2010, 10:00 AM
And dig this, for resetting the POA valve for 134a:

http://www.autoacforum.com/messageview.cfm?catid=20&threadid=7567

Stormking
06-20-2010, 11:45 AM
huh, it looks like someone put in 2 high side outlets so that one can run a high pressure cutoff switch, which would be a nice thing to do in most r134 converted cars if you are running an orifice tube ( stock would be relying on the temperature switch to accomplish the same thing)

lsrx101
06-20-2010, 12:12 PM
That is part of a POA eliminator kit in the last picture. There is an orifice tube in there along with a cycling switch. That's...umm....ok........in and of itself, but that accumulator has no business being there.

That shop really screwed up your system. They tried to turn your POA/TXV system into a modern type Cycling Clutch\Orifice Tube system. While this "can" be done, they aren't even close to doing it right. Even done correctly, it's a "downgrade" to the original system.

Did they say anything about changes to the original parts when you initially had the work done? If not I would demand they put the system back to original, with the Expansion valve (TXV) and POA valve in place, return your money and find a competent shop to do the work.
Compare your system to the one of a correct system. They should be identical. It looks like they owe you an evaporator, too. They hacked it to make the accumulator fit.

The links provided by darbysan and cjlaketexoma outline the right way to convert your car to R134a. That's how the shop should have done it. Those old POA systems kick *** once the valve is adjusted properly.

darbysan, Your 5th gen has an orifce tube and accumulator along with a thermostat to control the compressor. It doesn't use a POA and TXV like a 72.

pongo
06-20-2010, 12:38 PM
I know what I am doing, I have been doing auto AC work for a LONG time. All I am saying is that some systems that are designed to use R-12 just do not function as well with the higher pressure needed to make 134a as cold as R-12. And there are some auto systems out there that no matter what you do to the stock ac system will not be that cold when you switch to 134a. They cool but do not get cold. And one more thing that R-12 replacement "freon" that they sold in parts stores was unscented propane. If you don't believe me find a can of it and look at what the contents list says.

cubegleamer
06-20-2010, 09:23 PM
Thanks for all of the advice. I'm a new member here and new El Camino owner too. I think it's great that so many of you are willing to pass on your knowledge. To show my gratitude to this place and it's members I just became a "site supporter".

When I bought this Elky 2 weeks ago all of the A/C components were in a box in the bed. The guy I bought it from said he just didn't get around to putting it in after he had the engine rebuilt (I should have known better). He gave me a new A/C compressor in the box and told me that it just needed to be installed. He had installed some tall valve covers and hedman headers so the A/C compressor didn't fit. I imagine he tried to install it but realized it didn't fit anymore so he just threw everything in a box for the next sucker, yours truely. I had to buy new valve covers and a special bracket for the compressor that works with the headers. It's been a nightmare getting this A/C going.

I'm going back to the shop tomorrow to have the Expansion Valve (TXV) and POA Valve put in.

cjlaketexoma
06-21-2010, 04:09 AM
10-4 on buying a car with boxes of parts!! Mine came with strange crap that I have yet to figure out what it is. I think the guy I bought it from didn't even know himself what some of this stuff was. Actually, some of it has turned out to not belong to my El Camino or any elco for that matter.! it was just in there to throw me off. ;) So, I guess what I'm saying is, keep plugging and you will solve, and all the more satisfaction from slaying the beast.

lsrx101
06-21-2010, 05:43 AM
So the shop just assembled the system out of parts that you gave them? It's possible, then, that the system was pre-hacked before they even saw it.

350Caballero
06-22-2010, 05:10 PM
That is definetely a fifth gen system you have in there. The shop might have had to make something work out of readily available parts. One thing to keep in mind is that if you want the right parts for a vintage car you have to wait and you have to pay. I promise you most everything that is "correct' for your car would be special order or a custom build job...Cant always blame the shop for doing what you ask if you tell them to make it work

lsrx101
06-22-2010, 09:20 PM
Yes, but any shop that would assemble that mess without consulting the customer, then charge him $700 for a system that doesn't cool deserves the lions share of the blame in this case.
An accumulator AND a receiver/dryer on the same system, along with only half of a POA eliminator kit?
I could understand the OP, who likely doesn't know much about AC systems, assembling it this way if all of the parts were in a box and were supposed to be for the car. But a shop that does AC work? No way.

350Caballero
06-23-2010, 05:31 PM
There could also be other issues with the system too. I didn't say it was good. Who set the time frame for the work? I do auto repair and doing correct on a vintage car takes weeks even for something as simple as suspension a la 67 camaro

lsrx101
06-23-2010, 07:33 PM
There could also be other issues with the system too. I didn't say it was good. Who set the time frame for the work? I do auto repair and doing correct on a vintage car takes weeks even for something as simple as suspension a la 67 camaro

If you're talking about "numbers matching", you're totally right about waiting weeks for the "correct" parts. However, most replacement parts for that particular system, except new hose sets, are available within about 3 days from a number of reputable suppliers. Rebuilding hose sets has about 1 week turnaround time if shipping is involved.
I've waited longer for AC parts for a late model Toyota.

350Caballero, I've been in automotive repair for about 30 years and am usually one of the first to defend a shop being needlessly accused of wrongdoing. I often take it as a personal affront to my trade. In this case, however, there's just no excuse for that mess IMHO.

cubegleamer
06-23-2010, 09:26 PM
I asked around and ended up taking it to a reputable A/C shop for an estimate. The owner of the shop walked me through the system and showed me everything that was hacked up. A/C hoses were cut shorter and reattached with hose clamps... The line coming out of the evaporator was cut & bent so that the accumulator would fit. In the process of bending it they pinched the line and now it's sorta flat in one spot... so I need a new evaporator now. Orifice tube was put in where the expansion valve should be... He basically told me everything that lsrx101 said. The new estimate is $1,150. evaporator, new A/C lines, POA valve, expansion valve, R134a & labor. This must be the world's most expensive A/C.:let_it_all_out:

lsrx101
06-24-2010, 07:44 PM
I'm really sorry about your experience with the first shop. Have you talked to them about making things right?
Shoot, I'm mad at them and it isn't even my car.:censored:

Be sure to verify the new POA valve is adjusted for R134a. GM always said they weren't adjustable, but most shops familiar with POA valves know how to or know where to order them pre-set.
The POA is the heart of that system and having it properly adjusted makes all the difference between "good" AC and "I gotta turn this down some" AC.

cubegleamer
06-24-2010, 10:21 PM
The shop I'm dealing with now wants to use a new POA valve design that has a power wire connected from the POA to the compressor. Instead of the compressor running all the time it will only turn on when it's needed. Have you ever heard of this?

King John
06-24-2010, 11:19 PM
This topic is really sad. To give all of that money to a shop and get shafted really pisses me off. I rarely if ever take my car to anyone that I do not know, even if it is a "known reputable place", you never know if the guy that will be working on it is some "hack" mechanic or actually knows what he is doing.

Next time you take it in for someone to check it out, take a look at how many employees they have and how many certifications are on the wall. I went to my local Chevy Dealer's any on the wall I saw only a few certifications but they had over 20 people working on various cars (all under hood work, not changing tires and such). I asked the service manager about the rest of the guys working there and he told me only two are "certified" and the rest are "in training". Don't get me wrong, I am all for learning a trade, I just have a hard time paying premium dollar for "training work" that rarely gets checked out by the master mechanic onsite.

Didn't mean to hijack your thread, but it seams that more and more these days, people are being taken by those trusted to "repair" not "fix" the issues within the cars they own. Hopefully you get this resolved and also recieve the cool air that you are entitled to and deserve.:nanawrench:
Aloha'z

lsrx101
06-25-2010, 04:57 AM
The shop I'm dealing with now wants to use a new POA valve design that has a power wire connected from the POA to the compressor. Instead of the compressor running all the time it will only turn on when it's needed. Have you ever heard of this?

That's a POA Elininator Kit.
Personally I'm not a big fan, but they work ok. Since your original valve is missing it's a good alternative. That's "kinda" what the other shop was trying to do.
Instead of regulating the evaporator pressure with a valve, it cycles the compressor.