Shouldn't be adding refrigerant to high side, only low side. If it leaks down too low, it won't be able to draw it in. You probably waited too long. Best to take it to a shop where they're equipped to deal with it.

 

I only added Freon on the high side because at that point i was frustrated. the system holds a vacuum, and has been working for years! If what leaks down too low? the system?

 

If there is no refrigerant in it and the compressor wont come on it won't take a charge. The system has a low pressure switch that shuts it down if the pressure is low.

Recover - deep vac - and then charge the HIGH SIDE

If moist air was exposed to the inside of the system it wont work properly either. You really need to have it evacuated, maybe even change the drier?

 

1996 camry 5sfe The a/c wasn't blowing cold as it should. i finally after years of prognosticating broke out the gauges and added some 134a

I assume then that the system had some pressure over those years to prevent air and moisture from getting inside?

the a/c started blowing warmer air.

So you were getting some cold but then no cold?

I sucked it down and tried to reinstall from scratch.

You pulled a vacuum with a pump for at least 1/2 hour? What vacuum did you get?

is the condenser between the high side and the low side?

The condenser is on the high side after the compressor, after the condenser is the TXV valve, after the TXV is the low side.

 

I assume then that the system had some pressure over those years to prevent air and moisture from getting inside?



So you were getting some cold but then no cold?




You pulled a vacuum with a pump for at least 1/2 hour? What vacuum did you get?



The condenser is on the high side after the compressor, after the condenser is the TXV valve, after the TXV is the low side.
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i Know from prior Camry's I have owned the air was not up to their standards, so i added Freon. I am assuming when I added Freon to this system "and I only added a very small amount" it did something to the system and it stopped blowing cold and started blowing cool air. I had in prior years purchased a dryer and expansion valve for future use with the engine hot I replaced the dryer only.
I used Harbor Freight Gauges, and Vacuum pump. vacuumed for !/2 hour. What is the TXV valve?

 

The system worked it blew cold air! from owning prior Camry's I knew it was not up to par! Added small amount of Freon to system and it went from blowing Cold Air to Cool Air.

 

Back in the 1960's I was taught that you never charged an A/C system using fluid (tank upside down) only with gas. Reason was the compressors used reed valves (?) that could fail if fluid was used, and large slug of fluid hit valves. By time of these cars, did Toyota go to a rotary compressor? If not, compressor may now be trashed.

You explain that the system blew cold air, but not cold enough, then you added R134a, and system no longer produced any cold air. That's consistent with overcharging system, as-in adding too much refrigerant.

So what kind of pressures are you getting High & Low sides?

 

Back in the 1960's I was taught that you never charged an A/C system using fluid (tank upside down) only with gas.

On an initial fill with system off the vacuum in the system turns the liquid to gas pretty fast. After that fill on low side with gas, but that can take a lot of time. I tend to quick turn the can up/down and wait a short bit to speed things up.

 

oh buy the way the first thing i did was replace the dryer.

 

Did you add make-up oil to the system?

 

Sounds to me like you are not gaining access to the low side through the Schrader valve, when you first connect your gauge set to the system does both high and low side gauges read the same pressure with the manifold valves closed? When you say you suck ed the system down are you utilizing a vacuum pump? If so pull the vacuum from the high side and low side gauge which reads vacuum will show a vacuum, remember look for the low hanging fruit, someone would’ve had to do something really bad to that system to have things clog up, The compressor when not running is essentially a check valve in the system from the low to high side, there is a metering device at the inlet of the evaporator probably a TXV and lastly a liquid line dryer on the outlet of the condenser

 

OK the system was not always blowing blowing cold air as it should sometimes it would blow cold immediately and sometimes it would take a while to get up to speed! I was assuming that over the years it had a slow leak so that is why I added Freon to the system. after adding Freon to the system it went from blowing cold to cool air. the Harbor Freight Gauges read before adding Freon 20 low 190 high at a higher RPM from under the hood. after adding Freon the Gauges read 10-15 low 165 high. So instead of just letting a little Freon out I pulled the whole system down and replaced the dryer and vacuumed the system down -28 low side Pegged out high side negative 40 minute vac.
I turned the 30lb container upside down and bled the gauge lines and opened the high side without the engine running and gave it about 30 second shot of Freon. turned the container right side up and put it in a Postal scale Harbor Freight and zeroed it out. Started engine and compressor engaged, opened low side to the Freon bottle and it would not take any Freon. Gauges read 5 low 100 high. So I am assuming the TXV is clogged!!

Now am I missing something? is their any other answer why the system will not take Freon on the Low side other than maybe the system was already partially clogged and I stupidly thought it was low on Freon.
I tried to find chart for the Gauge reading for a 96 Camry at different temperatures but no one posted it.
anyway the temp was 82 at time of gauge readings.
Thank for your reply!

 

1996 camry 5sfe The a/c wasn't blowing cold as it should. i finally after years of prognosticating broke out the gauges and added some 134a from a 30 lb container to the system.It would not take very much at all. the a/c started blowing warmer air. instead of just letting some out, I sucked it down and tried to reinstall from scratch. now it only takes about 5 oz of Freon, and only on the high side! I am assuming the system is clogged! now my question is where? because it will only take Freon on the high side would it be the condenser? is the condehnser between the high side and the low side?

1996 camry 5sfe The a/c wasn't blowing cold as it should. i finally after years of prognosticating broke out the gauges and added some 134a from a 30 lb container to the system.It would not take very much at all. the a/c started blowing warmer air. instead of just letting some out, I sucked it down and tried to reinstall from scratch. now it only takes about 5 oz of Freon, and only on the high side! I am assuming the system is clogged! now my question is where? because it will only take Freon on the high side would it be the condenser? is the condenser between the high side and the low side?

OK for all you A/C mechanic wannabe’s, Let’s start at the compressor, the compressor discharges a hot high pressure superheated gas that is sent to the condenser and heat is removed from that gas to create a warm high pressure subcooled liquid, this liquid is delivered to the metering device just before the evaporator, a pressure drop occurs through the metering device delivering a combination of low pressure cold liquid and vapor at saturation to the evaporator, at the evaporator heat is extracted and leaving the evaporator is low pressure cold superheated gas that is sent to the compressor to continue this vicious cycle. LOL If you cannot charge through the low side and you can through the high side you are not open to the system through the low side Schrader valve

 

Clogged TXV? Note that if the 'Dash Removal' mentioned above becomes necessary, the procedure is an amazingly long and complicated job. It is beyond annoying that Toyota made changing the A/C expansion valve so difficult, as a consequence, many installers are replacing compressors without changing the TXV; that is a 'no-no'. I have had TXVs clog an internal screen in two Volvos during the 1990's the material was a black powder, presumably the source was rubber seals that wore out?

In my Toyota, if I push the passenger seat all the way back and crawl in facing up I can see and touch the two bolts which connect the TXV to the evaporator. When I changed my compressor I could not get a tool on the bolts to turn them out, so I left the old TXV in, luckily, my AC system has continued to work fine. The next time an AC repair requires depressurizing of my system I am determined to get that old TXV out without any &^#@!&^ 'dash removal' !!!

"Desperate times breed desperate measures". Think about taking off the fender and drilling a hole in the 'side' sheet metal (?), or drilling a hole in the firewall sheet metal (?). Then, using a very long 3/8 ratchet extension you might be able to get a 12mm socket through the drilled hole and onto the two TXV bolts (use an 'angled' socket adapter(?). Someone else can guide the socket on the bolt head from inside the car while you turn the ratchet?

If you get a procedure to work for changing the TXV without removing the dash let us know, it will help a lot of folks out. Take some pictures.

 

1996 camry 5sfe The a/c wasn't blowing cold as it should.

Going back on this, that does not say to me a clogged TXV, it says low refrigerant.

Sounds to me like you are not gaining access to the low side through the Schrader valve

That's a good possibility and it caused me to rethink. Possibly a defective quick disconnect.

OP, have you used this gauge set before?

OK for all you A/C mechanic wannabe’s, Let’s start at the compressor....

Thank you professor A/C.

 

Going back on this, that does not say to me a clogged TXV, it says low refrigerant.



That's a good possibility and it caused me to rethink. Possibly a defective quick disconnect.

OP, have you used this gauge set before?



Thank you professor A/C.

I assumed it was low Freon because The system was never as cold as Camrys are known for. Now the sight glass was milky bubbles at higher RPM from under hood, then after I added Freon it got better at RPM and only clear at idle.
I was wondering why the quick connect on low side when attached was tight and the connect on high side was loose!
maybe quick connect from Harbor Freight tools is defective and no I have only used gauge set once a couple of years ago and I had problems then as well come to think about it.

 

Is there a possibility that the system had a small clog in the TXV and when I gave it a shot of Freon it made it clog all the way? If not the TXV then is there anything else that can cause the low side to not accept Freon? I removed the Schrader valves and they look good. where can I get a pair of good quality quick disconnects? without breaking the bank?

 

Is there a possibility that the system had a small clog in the TXV and when I gave it a shot of Freon it made it clog all the way?

Anything's possible.

If not the TXV then is there anything else that can cause the low side to not accept Freon?

I guess an overfill? Maybe the gauge dials are not functioning? I don't buy anything worth buying at Harbor Freight.

I removed the Schrader valves and they look good. where can I get a pair of good quality quick disconnects? without breaking the bank?

If you use enough R134a (NOT FREON) to justify a 30 Lb cylinder then get a set of good gauges. I have Yellow Jacket, you can get them HERE Do not buy MasterCool, and do not buy a digital set.

 

This video explains how to check the TXV:

Hope it helps. Since the TXV was not repalced (and should have been) during a previous compressor change, you really don't have too much to lose by changing it now (even on a guess). Once it is out you will be able to see if it was obstructed. See my previous post for possible alternatives to removing the whole dash. I made a mistake referring to 12mm bolts holding the TXV on, they might be small socket (hex) head bolts.

 

I'm gonna throw my hat in the fight... what is the ambient temperature when you're doing all this? I don't remember the exact temp, but you cannot effectively draw vacuum on the system and pump out all the moisture if the temps are low (45 and below, or something like that). Also, the high side pressures are VERY dependent on ambient temp. You don't need a chart specifically for the Camry, standard R134a chart will do as R134a is what you're dealing with.

If the system was working better before, then look at the components you replaced. New dryer, you said. How new? Did it have the plugs in it like new ones are supposed to have? Did you hear a small puff when you pulled those plugs out, indicating that the dryer was under partial vacuum while in storage? If not, the "new" dryer could already be clogged with moisture.

 

Identical issue. So much good back and forth and then no conclusion...

 

Identical issue. So much good back and forth and then no conclusion...

I would suggest you initiate your own thread stating your issues and what it is you are seeking. I think you will find the forum helpful.