Cold in July...

[Andy4639]

How cold does your ac blow in the c-10? Lets see some proof on how good your air works.
I drove mine up to my dad's this past weekend. This was while at a stop light. I'm running 134a with classic air group's compressor and condenser kit for our trucks.
Outside was 88*.

Plus later model Chevy truck orifice tube and evaporator and factory cab vents.

[jeffahart]

A couple weeks ago it was 112 degrees out here. I flipped on my trusty air conditioning... it blew about 112.

I turn it on hoping for some sort of placebo effect...



j

[Andy4639]

Originally Posted by jeffahart

A couple weeks ago it was 112 degrees out here. I flipped on my trusty air conditioning... it blew about 112.

I turn it on hoping for some sort of placebo effect...



j

@ 112* I would doubt anything would feel good! Well except maybe a good adult beverages while floating in the river.

[Steeveedee]

Originally Posted by jeffahart

A couple weeks ago it was 112 degrees out here. I flipped on my trusty air conditioning... it blew about 112.

I turn it on hoping for some sort of placebo effect...



j

I wasn't driving my truck that weekend. We were coming home from the gun range on the 118 at Topanga and it was 119°. My AC is dead as well; it leaks somewhere. I'll chase that down once I get the running hot issue under control. So far it's been a fan clutch (that helped) and I'm running some flush detergent to clean the cooling system. It'll get there.

[Custom 68]

Andy when you charged yours what pressures high and low did you shoot for?

[67ChevyRedneck]

Originally Posted by jeffahart

A couple weeks ago it was 112 degrees out here. I flipped on my trusty air conditioning... it blew about 112.

I turn it on hoping for some sort of placebo effect...



j

My wife and I were in SoCal during the 4th when you guys had that massive heat wave. Luckly, it only reached the high 80's along the Coast, it was 120* an hour or so inland! We did a big 10 day trip where we flew into Phoenix, spent 2 days in the Grand Canyon, then a day at the Hoover Dam/Vegas (mostly hoover dam and Red Rock Canyon) and it reached 109* the day we were there. Here in the southeast it gets sweaty hot with high humidity and mid 90s, I'd always heard "it's a dry heat." My ass. 109* was freakin' hot. We then spent the next 7 days in Huntington Beach, man do they have great weather there. We overheard so many people complain about how awful hot it was (like 87*) and my wife and I just laughed.

I can vouch that truck has some cold ass air!

[mike16]

My friend in high school had a 67 Olds 88. After taking the ac/ heating system classes in our auto shop. he was able to tweek the ac to get the ac to put out snow flakes on humid late fall days.

[Andy4639]

Originally Posted by Custom 68

Andy when you charged yours what pressures high and low did you shoot for?

Dave when I charged it it 85* outside. I went by the 134a chart. That was ball park then we tweeked it a little. If I remember right we added a little more like 1/2 ibs.

[jeffahart]

Originally Posted by 67ChevyRedneck

My wife and I were in SoCal during the 4th when you guys had that massive heat wave. Luckly, it only reached the high 80's along the Coast, it was 120* an hour or so inland! We did a big 10 day trip where we flew into Phoenix, spent 2 days in the Grand Canyon, then a day at the Hoover Dam/Vegas (mostly hoover dam and Red Rock Canyon) and it reached 109* the day we were there. Here in the southeast it gets sweaty hot with high humidity and mid 90s, I'd always heard "it's a dry heat." My ass. 109* was freakin' hot. We then spent the next 7 days in Huntington Beach, man do they have great weather there. We overheard so many people complain about how awful hot it was (like 87*) and my wife and I just laughed.

I can vouch that truck has some cold ass air!

My son lives in Newport right next to Huntington. The weather is definitely more temperate there. A little cooler in the summer and a little warmer in the winter. I've actually been looking at houses out that way. I told my son I'm going to move in next door to him. He said stay away

I put in a replacement compressor last year. My AC actually gets a little cool but not cold enough for 112. I should have spent the extra money and got a good compressor. I should have listen to Ledzepp.

[stevenfromtexas]

since the topic was brought up, and if there is an A/C thread then can you guys move it......
also, sorry to hijack...

i just finished charging my vintage air GEN4 system. it's 100* in my garage,
according to Andy's chart, i am a little low on the numbers.

Low: 25
High: 275

the compressor does not cycle off either, curious if i need a little more refrigerant?

it's 60* on my temp gauge on the center vent.

[68panelman]

My old stuff has no AC, wah
My two modern vehicles, 01 & 03,
I have to throw in a can or two or freon during the season, and I can't get them any cooler than 58°.
Which is fine for me when it's 90 out.
I'll have to put the thermometer in the newest car,
('15 challenger,) to get a reading cause I'm curious now, never thought they blew that cold.

[Andy4639]

Originally Posted by stevenfromtexas

since the topic was brought up, and if there is an A/C thread then can you guys move it......
also, sorry to hijack...

i just finished charging my vintage air GEN4 system. it's 100* in my garage,
according to Andy's chart, i am a little low on the numbers.

Low: 25
High: 275

the compressor does not cycle off either, curious if i need a little more refrigerant?

it's 60* on my temp gauge on the center vent.

Are you running 134a are the old r-12 Freon?
How are you charging it. Do you have a fan in front of the truck blowing through the grille to simulate driving it?

I found this link.

https://forum.aircondition.com/forum...ve-a-c-systems

REFRIGERANT CHARGING PROCEDURE IN AUTOMOTIVE A/C SYSTEMS

We recommend reading this procedure completely before charging. You may need information before charging you want to keep handy. Have this procedure with you while charging. Although it can be done by a single person, we recommend having a helper around.

This procedure outlines the steps to perform a complete charge. These steps are not to be used to refill or make partial charges. Toping off requires system parameters monitoring and knowledge, specially in R134a-based system. Excessive gas will harm your system and will keep it from cooling properly. MORE REFRIGERANT DOES NOT MEAN COLDER TEMPERATURES

CHARGING IN GAS OR LIQUID - Please read step 10

Do not use the sightglass (if so equipped) in R134a-based systems as if were R-12 based.

SPECIAL EQUIPMENT REQUIRED

1) Vacuum pump

2) Gauges (R12 or R134a)

3) Service port adapter (as required in most R12-based systems) R134a systems do not require adapters other than the couplers in your gauges in the majority of applications

4) Refrigerant gas (R12 or R134a)

5) Optional: 2-3 ounces of specified oil.

**************

1. Make sure what is the required amount of gas. From factory, all systems have a decal under the hood that give the data. If the decal is missing or you are not sure, please specify make, model, and the type of refrigerant used and whether your system is a factory or an after market unit here. It is very important to know if your system has oil. Oil starvation is the main reason of compressor failure. Oil can be added to the system in two ways: with oil injectors or through the low side port under vacuum. The procedure to add oil through vacuum is described here. Some refrigerant charge and other useful specifications are provided here.

2. Connect both blue and red gauge hoses to the system's service ports. The discharge port (red hose) is located somewhere between the compressor and expansion device, either before the condenser or after it. In R134a systems, the port is the thicker of both, while in R12 systems is the thinner one. In some aftermarket systems, the port is located in the back of the compressor. If your ports are located in the compressor, the low side is marked by an "S" and the high side by an "H". Port caps have an "L" for low or "H" for high.

3. Open both gauge valves. Connect the common hose (yellow one) to the vacuum pump. Make sure both gauge needles are zeroed down. Needle is adjusted by turning a fine screw inside the dial. You must remove the plastic lens to do this.

4. Turn the pump on. You'll notice that both gauge readings begin to drop. The blue gauge's needle will even dip into negative values. The desired low side reading should be less than -25, while the high side will remain at 0.

5. After approximately 5 minutes, close both gauge valves. Turn the pump off, and observe the needles. Any movement will indicate vacuum loss. The faster the movement, the greater the loss. If after two minutes you don't see any needle movement, open both valves, turn the pump on, and continue vacuum for not less than 30 minutes. Close both valves then turn the pump off.

6. Get ready to charge. Have the necessary refrigerant amount handy. Cans make charging easier and more precise unless you have a charging cylinder or a precision scale.

7. Disconnect the yellow hose from the vacuum pump and connect it to the can tap or charging cylinder valve. You can charge in two ways: liquid (can upside down) or gas. Liquid charging is a lot faster but not recommended unless you extreme care or have experience. Traditional (gas) charging is slower but safer.

8. Once you've decided, and with the can or container connected, unscrew the top yellow hose connection (at the gauges) allowing refrigerant to escape for a couple of seconds. This will purge the air out of the hoses so you make sure that all you dispense is refrigerant. You can do this venting in liquid form so you can see when a fine, steady stream of refrigerant escapes indicating that all the air is gone from the hose. Don't breathe refrigerant and don't charge in a flammable environment.

9. "Flood" the system with liquid refrigerant (can upside down) by opening the red valve (high side) until it won't take anymore. Close the red valve. Jump the low pressure cycling switch (if so equipped). If you don't know what this is or where it is, ask for help here.

10. Turn the engine on. Turn the A/C into MAX on its third or higher blower speed. You'll note that both gauge readings are now positive. The red gauge should read between 100 and 150, while the blue gauge between 5 and 15. If you are charging with cans, don't forget to purge air out the hose after hooking a new can as described in step 8 above. Now, charge will continue through the low (blue) side (see note below) . If you haven't jumpered any switch (you don't have to), you'll notice the compressor cycling frequently on and off. That is normal. The cycling will disappear as you dispense more refrigerant. The only disadvantage of frequent compressor cycling is that charge will take longer. Needles will move up and down with every cycle. This is normal. Do not jump any switch unless you are absolutely certain!.

WARNING: DANGER

NEVER OPEN THE RED VALVE WHILE CHARGING. The red valve is to be opened only during pre-charge, vacuum, or when a system is evacuated. Its function is keeping an eye on the high side only. It must be closed at all times. If you have any doubts, wait until you receive information. Severe injury or death may occur. Remember: ALWAYS wear safety goggles. NEVER charge your system in a closed environment.

GAS OR LIQUID CHARGING?

There are two ways to charge: gas (can or cylinder up), or liquid (can or cylinder upside down). A compressor is designed to compress gas. Direct liquid charge will harm the compressor if suction pressure is not controlled. Liquid charging is faster, yet is riskier. Liquid charging should be made by professionals or under supervision. Liquid charging can be done if the suction port is away from the compressor (some compressors have the suction valve in its body).

Liquid charging can be done never exceeding a 50 PSI suction pressure. If you can't control it, charge in gas form. In cooler weather, cans may freeze. You may immerse them in water and shake them while charging.

11. Once about 2/3 of the charge has been dispensed into the system, spray water in the condenser to optimize heat exchange and speed the process. When you get the condenser wet, vent temperature is likely to raise. This is normal. You'll also note pressure drop in both gauges.

12. Once the specified amount has been dispensed, close the blue valve. Let the system run for a minute. Turn the A/C off and then the engine. Wait another minute and disconnect the couplers from the service ports. Disconnect the low side first. If you jumpered a switch, reconnect it too.

Optimum cooling performance is attained after 10 minutes of operation. Our own acceptance criteria is at least 50�F in the center vent to the driver side at idle after 10 minutes or less. Remember: cooling increases while the vehicle is in motion.

VERY IMPORTANT

Due to the physical properties and chemical composition, R134a and R12 charging amounts are different. Never, if you are retrofitting, charge the same or specified amount of R12 with R134a. If in doubt, please e-mail us here. Do not use this procedure if you are using any other refrigerant. This is just for R12 or R134a. Although procedures and parameters may be similar, we do not use nor recommend alternative refrigerants.

HOW TO DETERMINE OPERATING PRESSURES

Every vehicle has its own operation parameters specification. Depending on whether or not the vehicle has a factory or an after market system, and whether it was retrofitted or is still original, among others. There is no established calculation to determine the exact operating pressures.

The low pressure (blue gauge) should be 35 or less at idle, regardless of the type of gas. Only if you're running a dual system, the low pressure may be between 45 and 50 at idle.

The high pressure, for starters, is directly related to ambient temperature: the higher the temperature, the higher the higher the pressure.

Bear in mind that dispensing a complete charge without lowering the pressures with water will result in higher readings. This is normal, and that is why you should spray water in the condenser at 2/3rds of the charge or once you have completed it. You'll note an immediate pressure drop when you spray water in the condenser.

To obtain a ballpark high side value, multiply ambient temperature by 2.2 if you have an R12 system. If you have a factory R134a system, use 2.3. To convert �C to �F, use this formula: �C X 1.8 + 32.

Remember: this is only a ballpark. If in doubt, we have factory charts to help you determine the correct pressures. Please have your vehicle's make, model, refrigerant type, and year and click here.

Factors like a an obstructed or very dirty radiator and condenser, weak or inoperative fan clutch, weak or inoperative radiator fan(s), either electric or mechanical, will make pressures go up and impair cooling, even in mild days.

[el_fantasma]

I started a thread about this awhile ago

http://67-72chevytrucks.com/vboard/s...d.php?t=740230

You system certainly works better than mine.

[Steeveedee]

Originally Posted by stevenfromtexas

since the topic was brought up, and if there is an A/C thread then can you guys move it......
also, sorry to hijack...

i just finished charging my vintage air GEN4 system. it's 100* in my garage,
according to Andy's chart, i am a little low on the numbers.

Low: 25
High: 275

the compressor does not cycle off either, curious if i need a little more refrigerant?

it's 60* on my temp gauge on the center vent.

Take the truck out of the garage. The compressor cycles with pressure, so your charge has to be low for it to cycle. I'm not familiar with that system. Is it a CCOT system or does it have POA/STV?

[stevenfromtexas]

"Are you running 134a are the old r-12 Freon?
How are you charging it. Do you have a fan in front of the truck blowing through the grille to simulate driving it?"

134A
yes sir, fan in front of the pickup

thank you for the article!! fixing to read it now

[stevenfromtexas]

Originally Posted by el_fantasma

I started a thread about this awhile ago

http://67-72chevytrucks.com/vboard/s...d.php?t=740230

You system certainly works better than mine.

thank you for that writeup also!!

[stevenfromtexas]

Originally Posted by Steeveedee

Take the truck out of the garage. The compressor cycles with pressure, so your charge has to be low for it to cycle. I'm not familiar with that system. Is it a CCOT system or does it have POA/STV?

ok, i'll put the gauges on it out side. my apologies, i'm not too sure what CCOT, POA/STV is......

it does have an expansion valve and not office tube, if thats is what you are referring to. the Vintage Air system is what i put in. this is the system several guys are using.

thank you very much for your suggestions......fixing to check it out in a bit

[Andy4639]

Is it the whole system from vintage air? They should be able to tell you exactly what amount of Freon to put in it.

If your using the old A-6 compressor that came with the truck they want cycle like the new ones unless it's been modified to cycle.
Make sure your hot water valve is completely closed off. If it's letting hot water by it will cause the cab temps to not get as cold as they should. Easy to check put your hand under the passenger side dash looking at the picture and if any of the air stuff feels warm it's not shut off good enough. I put a manual shut off in mine plus I completely sealed the cowl opening off.
I run my passenger side vent open all the time and the drivers side shut. This in effect is like a new vehicle set on max AC with no outside air coming in.

[stevenfromtexas]

yes sir...all new system.

ok, all is good!!!! i reckon my impatience got the best of me sorry
backed my pickup out and hooked the gauges up and right away that turkey cycled just like it's supposed to. it is still a little on the low side indicating a little more juice and about 58* on the vent......its 95* today in Central Texas with approximately 963% humidity +/- 3% ruff firefighter estimates