AC Repair Help
AC will NOT stay on after about 2sec. Worked before until I added some Freon. Quick story:
- Since purchasing car, AC has worked but recently not so well
- Added r134 can from Walmart in 110deg heat
- Worked well last summer
- Now AC light will NOT stay on past 2sec… ever
......Pushed Schrader (low pressure) but seems nothing releases
......Tried filling but without AC on seems I cannot
- Thought maybe I could have overfilled in summer and bad pressure when lower temps. But I’d think pushing Schrader you’d hear or see something release.
- Might be nothing in the system now… if that’s the case potentially my Schrader valve is the culprit since its really the only part I’ve messed with when adding Freon.
Any advice on where to start would be great!
IF you leave it ON high/max Cold, and put on low pressure charge..
The compressor should eventually come on and cycle for a moment..
As it takes more freon, it will cycle ON longer and longer..
You really need to get pressure gauges on it though
IF you leave it ON high/max Cold, and put on low pressure charge..
The compressor should eventually come on and cycle for a moment..
As it takes more freon, it will cycle ON longer and longer..
You really need to get pressure gauges on it though
For gauge, I have the can attachment but other than that no AC equip.
If I press the low schrader valve, I would see, hear Freon correct... should be obvious? If nothing, prob nothing in the system?
Was using an old can though, but did get cold. Should I try new can?
Both high and low valves, nothing releases when depressed.
How would i get dye in if compressors not on?





The HOT WATER will cause the liquid in the can to vaporize and go into the system faster AND get ALL of the contents out of the can!
IF,,,,,,,,,,,,,,,,,, The system is really empty, it will take at least TWO cans to get it cycling properly and then stay on. Then some of a third can will have to be added while you monitor the pressures.. Like "foggy" stated, you really need a set of gages to see what the pressures are and get the right charge. There is a detailed specific system set up in the service manual and the chart that is needed to followed to get the pressures right. Temp, humidity and engine RPM are taken in to count.
The real correct way to service the charge is to MEASURE the charge. If it truly lost all the pressure you should change the receiver dryer, the orifice restrictor tube and VACUUM the system out and then refill it with the correct Pounds/OZs.
Last edited by Bill Curlee; Apr 12, 2018 at 02:18 PM.
I did register some low side pressure with the can but maybe so low didn’t notice any releasing when depressing valves.
At at a reasonable pressure, if Shraders are pressed there would be noticeable release of refrigerant correct?
The Best of Corvette for Corvette Enthusiasts
Take a look at this post. It has detailed instructions to check/add refrigerant.

-These are the CliffsNotes:
Check your pressures against the chart below. Make sure you take your readings with:
- Engine @ 2000 rpm
- A/C in coldest setting
- Fan at maximum speed
- Both windows down
- Thermometer in center air vent
When adding refrigerant, pay attention to both pressures, otherwise you might end up with the high side sky-high trying to get the low side to the chart's value.
Let us know how it goes.
Last edited by GCG; Apr 12, 2018 at 03:28 PM.
I'm going to try a new can in hot water to see if I can get the compressor to stay on... if not I'm pulling it.
The can of refrigerant in hot water, as suggested by Bill Curlee, sounds like a good idea. I would try to load the can using the A/C manifold gauges and if you get the compressor to stay on, just follow the rest of the procedure. The chart will give you your target pressures.
Give it a try and let us know how it goes.
Last edited by GCG; Apr 13, 2018 at 09:17 AM.
The bolt in the back of the compressor holding the AC lines, is that a 13mm like the others? Seems I can get to it with a universal, but there’s gonna be a bunch of swear words.









