a/c trouble

[kody]

having a/c trouble,small line coming from evaporator gets coal and stops at orifice tube.high pressue line gets hot,thanks for any help,its been mighty hot here.not cooling at all.

[pontgta]

Originally Posted by kody

having a/c trouble,small line coming from evaporator gets coal and stops at orifice tube.high pressue line gets hot,thanks for any help,its been mighty hot here.not cooling at all.

Ok,

the way the lines route... From the Compressor You have 2 lines one big, and on small. The small line goe to the Condensor. Big one comes form the evaporator. The small line exits the condensor, and goes to the evaporator, which should be hot untill it enter the evaporator(though the orfice tube). The large line exits the evaporator, goes through the accumlator, and should be cold. Pressure is what makes everything work correctly. So what are your pressures?

[gchemist]

Two things come to mind. Does it have adaquate air moving across the condensor/radiator? Not having enough air is the primary reason A/C get hot/build pressure and fail. Second, your office tube may be clogged. You may save yourself some repairs if you replace the orfice tube before complete failure. If the orfice tube clogs, two things will happen. One, the seals on the compressor will fail. Two, the compressor will fail, burn the clutch, as it tries to pump the freon into the evaporator.

[kody]

ok, seems like all refrigent has leaked out, last year had everything replaced but evaporator and condenenser.i started to open line at orifice tube,a lot oil starts to come out is this normal.i would like to repair myself,thanks for all your help

[pontgta]

Oil is normal, just means you have to put back in, but the first step would have been to find the leak. I would put back together, put dye, and then find the leak. I like the dye because it is so easy to use and cheap. I also use an electronic leak detector to pin point.

And yes its been one hot summer.....

[gchemist]

Check the low pressure switch. It's a primary point of leaks. Compressor seal next. High pressure switch third. Evidence of a leak will have oil all over it.

[kody]

thanks,i will check these later today.

[kody]

dont see any evidence of any oil leak,could it be leaking in the evaporator?i cant see inside the box.i tried the dye allready and nothing,

[gchemist]

I should state, large leaks like seals and connections will have oil. The low pressure switch may not. Unscrew the low pressure switch. Check it for cracks. A hairline crack is enough to leak out coolant. If the high pressure switch has failed, you will need a detector to know for sure. If you open the system up. Replace both switches as a precaution. I didn't replace the high pressure switch once. Since the problem was not obvious, it costs me another $200 to replace and recharge a system.

[kody]

where is high presure switch located,thanks for your time.

[pontgta]

The dye did not help? How much pressure were you seeing? Hard to find leaks are best seen at night with the dark light. I have never had one i could not find. High pressure switch is on the compressor or on the small line has 2 wires just like the low pressure one

[gchemist]

Here is a picture of what happens when an orfice tube clogs up.



I kept driving with the A/C on until failure. Being 480 miles away from my garage, I bought a bypass pulley and made it home several days later. I had to drive at night and early morning due to weather. The cab does get hot due to the constant air recir fan.

[kody]

does not seem to have any pressure now,my compresser does not have switch on the front,like gchemist.its a 84 c10 with r4 compresser.

[pontgta]

Ok , so no pressure. You have to pressurize the system again. If you already put dye, then no need to put some more. After the system is pressurized run it, a few times to get the dye throught the system, then check with black light. Sometimes you can see the dye with out the light, but i highly recomend using the light. I have found that my paticular light works better at night. when i have a leak, It really glows at night.


If you have no freon left in the system, you have to find the leak, before replacing parts, and never finding the leak. This will save you money in the end.

[kody]

thanks for the help,where can i buy a black light?ill keep at it.

[pontgta]

You can buy one at the autopart store.. I bought mine at the AC supply store, but that is because i do residential AC. The ones at like autozone or Advance are good ones to use. I think they are not more than $20.

[kody]

ok,got uv light at advance auto,got pressure on a/c.still cant fine uv dye leak.compressor makes belt squell when you rev engine,does not at low rpms.i am thinking compressor may be bad.i like that uv light.

[pontgta]

Run it a day or so, it just has to run through the system. I have found some the next day, some very quicker, but the best was at night. what kinda pressure do you see? I would note the pressures and check in the next day, should be just a bit off with the outside temp, but not extreme. squeal...belt?

[kody]

dont seem to have any presure on the high port side,small line coming from evaporator to orifice tube has got ice on it.high side has about 20 psi.

[pontgta]

Originally Posted by kody

dont seem to have any presure on the high port side,small line coming from evaporator to orifice tube has got ice on it.high side has about 20 psi.

I think your are mixing up low and high sides. can you take pics and post please.

What kinda guages do you have? The coil in front of your radiator is the Condensor. The coil on your firewall is the evaporator. The orfice tube is on the small line going to the evaporator. Ice on the big line coming out of the evaporator with 20psi would be normal. You need to charge it about 30-35 psi to get the ice to go away, and the compressor to stop kicking on and off.

[kody]

now have 30 psi coming from low side(big line) still can not find leak with uv light.a/c gauges came from harbor freight.i think high presure gauge is broken.belt is still squeking a little bit when you give it gas,but its alot better,thanks for all your help.

[pontgta]

Ok, how did you add the dye? Adding it with a little oil make it better. how much did you add?

[kody]

looks lile a new product at advance auto it has its own dispenser,.with engine runing and a/c on push in and hold for 3 seconds on low pressure port. bought yesderday with uv light.

[pontgta]

I normally use the Dye that you have to inject, but any of the dyes should work. Just run the ac, get the pressures about 35-45 depending on outside temp. Make notaions daily how much pressure you have lost.

Did you say you had no pressure when you started? Like 0? That would be a big leak. Unless you lost it overtime. Did the ac go out in one day?

LIke Gchemist suggested oil around the lines indicate the leak. Follow all the lines with the light at night very closely. when ever i inject the dye it glows for me( hate getting it on my hands or engine bay because it appears like spots allover.

One more thing..... DO NOT WASTE MONEY ON LEAK STOPPERS....

[pontgta]

ADVANCE DYE

which did you use?