Ac compressor swap issues

[Austin86250]

Replaced compressor, dryer, all orings, and out in a red oreifice tube, vacuumed it down for 30 minutes and then it held 30 inches for 10 minutes no leaks

Now trying to fill up I hit a stopping point 70 low side 100 high side compressor goes on for a split second nothing for 2 seconds and repeat

It was r-134 before but it had a blue orifice tube do I need to adjust the pressure switch? Or?

 

[BlindAmbition]

Is the AC clutch pressure switch itself possibly defective? I've got like 5, can send you one if needed.

 

[Nero]

I've always swapped them to the red orifice, they seem to work well up to 110f ambient.
You may need to replace your switch, it could be finally wearing out.
How much are you filling it to? Are you using just the cans or are you using a machine? I typically put 2.7 lbs for a good cold ac.

 

[Austin86250]

I've always swapped them to the red orifice, they seem to work well up to 110f ambient.
You may need to replace your switch, it could be finally wearing out.
How much are you filling it to? Are you using just the cans or are you using a machine? I typically put 2.7 lbs for a good cold ac.

Just 12oz can, I’ll get a new switch thank you! What should I be shooting pressure wise?

 

[BlindAmbition]

You'll need way more than a 12oz can. Switch may not be the issue, could just be too low a charge. Look up a pressure-temperature chart for R134. It is all based on ambient air temps and other voodoo. I'm sure there are some good videos on YouTube. Highly dependent on ambient temps, so I won't give a specific pressure to shoot for.

 

[Austin86250]

Forgot I had one that I never installed, so that was easy now shes runnin and blowing cold, how are these pressures lookin?
It’s 87* outside right now

 

[gnathv]

Try this. Looks like you‘re still low.

 

[Nero]

You'll want to reference the pressure/temperature chart for manual filling.

If you're having a hard time adding more, a trick I use is to run the system, and fill off the suction line (low pressure) as it will literally suck the can empty.

 

[Austin86250]

This is awesome I didn’t know how quiet a/c compressors could be, my old one it was just as loud as the motor at idle, I added some uv dye in the system last night and ran it though for 20 minutes an hour later nothing was visible I’ll have to see how it did overnight

 

[Austin86250]

It’s 73* outside so let’s round to 75
According to this diagram I should be L35-45 H 150-170
It would appear my low is too low and high is too high
Stays on at idle and when I give it some throttle it cuts out for 4 seconds and fires back up business as usually

 

[BlindAmbition]

Here is a basic guide, it's approximately what I have done in the past.

Refrigerant charging procedure in automotive a/c systems - Automotive Air Conditioning Bulletin Board

REFRIGERANT CHARGING PROCEDURE IN AUTOMOTIVE A/C SYSTEMS We recommend reading this procedure completely before charging. You may need information before

forum.aircondition.com

Pressures seem alright to me, does it run cold? Was it originally an R12 system?

 

[Austin86250]

Here is a basic guide, it's approximately what I have done in the past.

Refrigerant charging procedure in automotive a/c systems - Automotive Air Conditioning Bulletin Board

REFRIGERANT CHARGING PROCEDURE IN AUTOMOTIVE A/C SYSTEMS We recommend reading this procedure completely before charging. You may need information before

forum.aircondition.com

Pressures seem alright to me, does it run cold? Was it originally an R12 system?

If the pressure seems right I’m pleased it is some very very cold a/c coldest I’ve ever felt for an r-134 conversion by far
I guess I’m just being a little over concerned I don’t like to have to do stuff twice

 

[Nero]

Temerature readings should be taken at the fittings, and expect a variance of about 5-7 degrees.l due to thermal loss.
With low too low and high too high, either wrong orifice or undercharged.

 

[Rdnck84_03]

I always fill mine to around L40 at about 1700- 2000 rpm, since that is where the engine spends most of its time you don't want the compressor cycling in that range.

But take that with a grain of salt because I have absolutely no HVAC training. Just something I was told years ago and has always worked.

James

 

[franklin2]

You'll want to reference the pressure/temperature chart for manual filling.

If you're having a hard time adding more, a trick I use is to run the system, and fill off the suction line (low pressure) as it will literally suck the can empty.

Always charge the system from the low side. Never charge the system through the high side.

When I converted my truck to 134a, I had to tweak the low pressure switch a little bit. When it's hot outside, and you have the lever on regular A/C, the compressor should not shut off. If it does, you can unplug the wiring connector on the low pressure switch, between the terminals you will see a small screw. You can tweak this screw to change the cycling of the compressor.

If you charge the system on Max A/C, make sure you roll the windows down. If you don't, it keeps recirculating the cold air through the evap coil, and this will keep the low pressure side unusually low. This will tend to make the low pressure switch cycle because the low side pressure is low. That's ok except when filling the system, you need to keep the evap coil warm to fill it correctly.