A/C Issues

[94carolinaSHO]

Hey folks
I have been working on trying to get my AC working by recharging it. Once I got freon in there the clutch engaged on the compressor but makes some weird noise for about a minute. I put two bottles in it from the kit from Autozone and the gaged is maxed out past the red so more than 80 PSI I would guess to explain it. The vent temp was blowing at about 110 and only dropped some. Than the car would cut out and stall. The only way to get to restart and idle without dying is to disconnect everything wait a minute and it would fire right up. It will not take any more freon without cutting out. Now from doing some searches I understand about a shimming procedure but can't finda writeup about it. What does the high pressure switch do? Sorry for all the questions. AC work is relatively new past the point of a recharge. The only other thing I can think of is to put a vacuum on it and see if I have a leak. Does anyone know if the freon you get glow with a black light?
please help. An hour driving in a hot car is getting real old. Thanks

 

[Bob Gervais]

It's overcharged.

 

[ShadetreeSHOguy]

It's overcharged.

Truth.


It being overcharged im pretty sure there's a few seals damaged in the compressure do to it being that overcharged.

The ac system needs to be evacuated of all freon and recharged to the proper levels. only then will you be able to pinpoint the issue, if the compressor isnt fried due to the overcharging.

 

[zak]

Or the compressor is not even turning (needs a shim removed) . . . . pretty hard to overcharge R134a in my own experience.

 

[projectSHO89]

Actually, it's impossible to overcharge when the compressor isn't even running anymore....

 

[Bob Gervais]

Hey folks
I have been working on trying to get my AC working by recharging it. Once I got freon in there the clutch engaged on the compressor but makes some weird noise for about a minute. I put two bottles in it from the kit from Autozone and the gaged is maxed out past the red so more than 80 PSI I would guess to explain it.

Maybe I'm just tired, but I can't see where he's saying the compressor isn't engaging.

 

[Bob Gervais]

Or the compressor is not even turning (needs a shim removed) . . . . pretty hard to overcharge R134a in my own experience.

It'll only do that if it's in double shear design with a front tuck dismount.:swing:

 

[94carolinaSHO]

To clarify the compressor is engaged and turning. I was wondering about overcharge but when I first started and checked the pressures there was none and the compressor wouldn't engage. So once I started charging all of the sudden it kicked on. Kinda startled me sin e I wasn't expecting it. But I have yet to have cold or even remotely cool air even with just one can in. I let it sit and run for a bit after the one can and my thermometer never changed. So I will have to look into a place to empty the system. How does that work exactly? What they take do they give the same amount back even if there is a time period in between evacuated and charging? Thanks a lot for all the help and feedback. With all the issues starting to o cur and pretty much no time to ever do what I need to do I was close to looking for something else. But the forum and my stubbornness changed that for me. Keep it coming.

 

[zak]

The system was likely full of air then - you would need to vacuum this out then refill. Did it hold pressure overnight?

If there is an obstruction somewhere (typically the line that has the orifice) then you can get very high operating pressures.

Check the tool rental places, some of them rent HVAC vacuum pumps.

When the compressor came on did it stay on? How long?

 

[93rev2sev]

I'm also going to guess that the oriface tube is clogged.

 

[projectSHO89]

It's pretty hard for an operating compressor to leave the low side pressure above 80 psi. Check the CENTER COMPRESSOR SHAFT for rotation instead of relying on any observation of the clutch plate. A faulty clutch can allow the plate and pulley to rotate without rotating the central shaft.

In a charged but shut-off system, both low and high side pressures will reflect the "static" pressure which can be estimated at around 1.1 to 1.4 times the ambient (under hood, not outside) temperature. A more precise estimate of the static pressure can be obtained by accurately measuring the temperature then referring to an R134a P-T chart. When the compressor (it's just a pump) engages, the low side (suction) pressure should be "pulled" in the direction of vacuum while the high side (discharge) should be "pushed" to a higher level of pressure. If the low side pressure remains at the static pressure, the pump ain't pumping and you'll draw no refrigerant into the system from the supply container. That's why I made my initial observation.

If the orifice tube were clogged, the low side pressure reading would be extremely low, perhaps even into vacuum, and the high side reading would be extra high during compressor operation.

You really need to get a manifold gauge on there so you can see both sides of the system. Trying to diagnose with a low-side only reading is like trying to see a 3-D movie with one eye covered.

 

[94carolinaSHO]

Well thanks for the information. I will have to check into getting it evacuated and make sure that it will hold a vaccum. I will also check out the center shaft for the compressor as well. Thanks for the info. We shall see what happens.