I think I overcharged my AC?

[Razorbackcruiser]

As the title says, I think I might have overcharged my AC system. I live in Arkansas and wanted to make sure my AC worked before it gets really hot here. It wasn't blowing really cold so I bought a low side pressure gauge read the instructions plus the FSM and dove in.

It was reading low so I added two cans of R134a and it started blowing ice cold but the sight glass was still showing bubbles with the AC on high around 1500 rpms. I probably should have stopped there but of course I didn't. I went ahead and added another can for a total of 36oz. Now I read it should be around 30oz +/- 1.5.

I'm over around 4 or 5 oz but it's still blowing ice cold and the sight glass is running clear but doesn't foam when the system is turned off (not even for a second, which I read it's supposed to).

So my question is, Is this going to cause problems? If so can I bleed some of the R134a out to bring it back into specs. I searched but never found a definitive answer.

Thanks in advance for any responses.

 

[CJF]

Won't hurt anything to bleed it off a bit.

How often is the compressor cycling? Main symptom of an overcharge is rapid on/off cycling.

 

[Razorbackcruiser]

Haven't noticed any rapid cycling on and off so I guess that's good. How would you go about bleeding off the extra?

 

[Tacoma4life]

I would bleed some off. Get somthing pointed to push in the needle on the low pressure port, then cover it with a large clean rag while you depress it so you don't spray yourself in the face. Be warned, it goes fast and you'll lose some oil...

 

[MrOffshore]

Word to the wise...wear safety glasses anytime you work with this stuff...the old adage, better safe than sorry couldn't be more true when working with A/C systems.

 

[Rwhat]

Get a set of manifold gauges and with it running, see what your high and low pressure readings are.
Also be carful not to add the R134A in liquid form into the low side port. You will hydrolock the compressor.

Also if you added too much you have a chance of the safety blow off valve open up or the high pressure cut off switch will kick in. This is from what i read and been researching on A/C systems.

 

[1972FJ55]

The factory spec for refrigerant level is 1.87 lbs or 30 ozs. If the system still had refrigerant in it when you started, then you could be significantly overcharged. You might not see a problem until the ambient temp gets hot, then the high-side pressure could start tripping the hi-pressure switch. That high pressure also puts unnecessary stress on the compressor and discharge hose. Ideally, you'd want to start over from empty, but if you have some gauges, look for about 25psi on the low-side and 200psi on the high-side.

 

[inkpot]

Get a set of manifold gauges and with it running, see what your high and low pressure readings are.
Also be carful not to add the R134A in liquid form into the low side port. You will hydrolock the compressor.

Also if you added too much you have a chance of the safety blow off valve open up or the high pressure cut off switch will kick in. This is from what i read and been researching on A/C systems.

It that caused by holding the can upside down so it flows faster? I've heard that's a No No. John

 

[scotia]

If you are really unsure of the amount in the system....start over from the beginning. If there is too much....you will know about it on a very hot day when the head pressure kicks out the high pressure switch and your condensor cant pull out all of the heat. It will not be able to condense all the gas. It can cause damage down the road if left in that form. If you can borrow a vacuum pump from someone, I can walk you through the process....it is not hard at all when weighing in refrigerant.

 

[TX Cruiser]

He's got a leak, it'll get to where it needs to be, eventually.

Most orifice tube cars can take holding the can upside down, expansion valve cars like side ways after you crack the can.

Get your pressures right for your climate. Set it to an ambient temperature on a given day when you watch what the system is doing with proper gauges.. You are going to have to take into account how well your fan clutch works and how well the flow is over the condenser. 1.94 lbs of charge is the max. I lean more towards more oil and less charge sometimes, but it depends on the application.

You really need to find out where it leaked, first. Otherwise, you get to do it all over.

 

[93Chewbacca]

You really need to find out where it leaked, first. Otherwise, you get to do it all over.

X2. I think there are some UV dye kits for diagnosing where the leak is, I'm not sure what the tools cost to do this though.

 

[95LCMachine]

The factory spec for refrigerant level is 1.87 lbs or 30 ozs. If the system still had refrigerant in it when you started, then you could be significantly overcharged. You might not see a problem until the ambient temp gets hot, then the high-side pressure could start tripping the hi-pressure switch. That high pressure also puts unnecessary stress on the compressor and discharge hose. Ideally, you'd want to start over from empty, but if you have some gauges, look for about 25psi on the low-side and 200psi on the high-side.

These were the exact numbers I was looking for, and making a reply is the only way I can be sure to find the thread again!

Thanks for the poop.

 

[TX Cruiser]

X2. I think there are some UV dye kits for diagnosing where the leak is, I'm not sure what the tools cost to do this though.

I suggest getting a set of Master Cool gauges, an oil injector and a vacuum pump, first. I have a sniffer that has never been used, it was a gift. Waste of money. UV dye can be seen with the naked eye so a black light and yellow glasses are a waste of money. Just look for oil, black slimy stuff on components and unions, and you'll be fine. A bottle of soapy water never hurt if you pressurize the system. It's great for checking things like schraeder valves. I'll probably get reamed for this, but I don't mind using compressed air to put pressure in the system. Think about the boiling point of water when under a vacuum. Nitrogen is preferred.

You can inject or suck oil into any system that is under vacuum, just stick your charge hose down in the dye/oil bottle and open up either side, then chase it with freon. Don't ever fire up the compressor with the high open and a can on the end.

 

[Rwhat]

I suggest getting a set of Master Cool gauges, an oil injector and a vacuum pump, first. I have a sniffer that has never been used, it was a gift. Waste of money. UV dye can be seen with the naked eye so a black light and yellow glasses are a waste of money. Just look for oil, black slimy stuff on components and unions, and you'll be fine. A bottle of soapy water never hurt if you pressurize the system. It's great for checking things like schraeder valves. I'll probably get reamed for this, but I don't mind using compressed air to put pressure in the system. Think about the boiling point of water when under a vacuum. Nitrogen is preferred.

You can inject or suck oil into any system that is under vacuum, just stick your charge hose down in the dye/oil bottle and open up either side, then chase it with freon. Don't ever fire up the compressor with the high open and a can on the end.

I respectfully disagree on not using a sniffer. How will you finds leak near the evaporator?
without pulling the dash apart?

 

[lispeej]

I had a small leak that wasn't detectable sometime last year. My ac wasn't as cold as I wanted, so I added a bit too much,,,kinda like what you did. I ended up blowing my ac condensor right at one of the corner welds. It was a pricey fix. So, I'd reccomend starting over or releasing some pressure if you don't want to end up blowing anything.

 

[Razorbackcruiser]

I appreciate all the advice guys. I went out and released some of the R134a, quite a lot to be honest, and my sight glass still had no bubbles with the AC on high. When I shut it off now I get some slight bubbles for a second or two then it runs clear so hopefully I'm close to spec.

I'm going to borrow someone's gauges here in a couple of days to see where I'm at. It hasn't gotten hot here yet so the thought of me blowing something really has me worried. I'll say this, it's blowing ICE COLD now though.

Thanks again.

 

[lispeej]

walmart and other fine auto parts stores sell a gauge kit with r134a stuff for fairly cheap. Buy it now before the price goes up. Good luck.

 

[TX Cruiser]

I respectfully disagree on not using a sniffer. How will you finds leak near the evaporator?
without pulling the dash apart?

Good point. Dye the system, look at the condensate. Use your sense of smell. It's damn hard to find a pin hole leak in or around an evaporator without removing parts. It's just the same as it is to find a shaft seal leak that seems to only leak while at rest, in a certain position. Some things you see more than others, and you tend to rule things out per application.

A LandCruiser blowing the evap tells me there's trash in the evap housing. It's not too much work to figure out why parts failed, but it's a question everyone needs to consider.

Most every compressor failure with the 10PA17C (rare) is due to high head pressures. If you don't get good flow across the condenser, something is going to blow. The evap is low pressure, 1/4 of the expansion valve feeding and draining it, is not. Remove the grommet at the fire wall, look and feel for leaks.

I'm tired, surely I missed some obvious ones. G/L.

 

[86tuning]

I respectfully disagree on not using a sniffer. How will you finds leak near the evaporator?
without pulling the dash apart?

dye coming out the drain tube is the most obvious clue

Our shop has a sniffer, nobody uses it. We just dye & charge, then wait a few weeks and check it again, or at the next maintenance service.

 

[fooldall1]

Those pressures referenced above - 25 low side 200 high- is that right for Dual-Air systems that still work (not capped)? And what ambient temp and humidity is that the correct pressures?

Also, has anyone ever had a scenario where the drivers side vents were 48 and the passenger side was closer to 68 with the rear air on? When I turned it off, the passenger side dropped to 60.

I'm thinking perhaps my condenser coil is leaking or the expansion valve but i need to dye check it. I also added some Red Angel about 3 months ago and it seems to have fixed whatever leak I had... but I'm totally confused about the temp differential on the driver and passenger side.


Thankfully, it's not July (I'm in FL).