I,

what is my possible problem ?

-Pressure : 70 psi before start- 40 psi when compressor running.
-No squeeking from the compressor
-The engine rev up when I push the a/c switch.

But the air still at the same temperature as the exterior temperature.

96 Maxima in really good shape.

Thanks

 

do the a/c lines feel like they are getting cold?

 

the low pressure one seems to be a bit colder than the ambiant temperature and the high pressure is hot.

 

Do you have auto climate control, or manual one?

Do you hear the clutch cycling often?

Is there any bubbling or streaking in the site glass?

S

 

Another thing to check is to make sure the low side (which is where you have you gauge) is not pulling into a vacume .
with the car running and a/c on, rev the engine up to about 3500-4000 rpms for abut 10 seconds and watch the gauge. if it goes down into the vacume range you have an expansion valve that is stuck .
if you have access to a full set of gauges that can be very helpful too.
hope this helps

 

Same thing happened to me after I had my engine compartment cleaned on my 95 last summer.Evidently,while doing the steam cleaning some of the wires had gotten brittle over time and just broke apart.Fortunately,they took care of the problem at no cost to me.After the wires were fixed my A/C worked great.

 

- Manual
- If I hear the clutch cycling, yes.
-No

Thnaks.

Could be the compressor? Can I change it without removing all the gas?

 

same problem.all is runnig ,no cold air...my friend has same trouble and in nissan service nothing...why is compressor runnig,should be death??

 

Does it cycle often? If it does, you could be low. Not sure if it's the compressor with whatyou gave us. And no you can't change the compressor without removing/loosing all the freon.

S

 

Have the system evacuated and recharged professionally with the correct amout of refrigerant by weight put into the system.

 

First, thanks to everyone for the help.

But, im not sure what do you mean by "cycle often". Means if I use the a/c often to prevent a compressor jam?

I know that the compressor possibly work, because the gage is at 70 psi when a/c 's off and when the compressor running it still stable at 40 psi...

That's strange, seems a common problem to 4th gen, but no answers.

Btw, it worked in 2-3 years ago, I taught it was a leak, but no got the oem freon and no leak...

 

EDIT : FIXED

Hi, I got a hardware problem. The clip on the pressure gage is cheap. Even if it well fixed on the low pressure valve, the reading is bad. You have to push on it to get the real value.

So after some testing, I got 50 psi OFF and 25 psi ON. Put a red tek can and it works. Got a real 70 psi OFF and around 32-35 psi on. The air is realy cold



Thanks

 

When I meant cycling...the A/C will click on...but click off really quick. Usually if it's doing that, it's low on coolant. Glad you worked it out.

S

 

I won't use R12a. It is basically hydro-carbon and it is flammable (propane, butane). R134a should work well enough.

 

I cant find here, all r134, even the "a" is illegal in my country.

But Redtek use r12a, and it should be compatible with my oem r134a.

Redtek.com quote :

"BENEFITS

* Operation: RED TEK® 12a possesses similar volumetric refrigerating effects to R12 or R134a refrigerants. Operates at lower head pressures and offers improved cooling properties, performance and energy efficiency verses R12 or R134a. Can be used effectively in R12 or R134a refrigeration systems without major "retrofitting."

* Lower Cost: Less expensive than R12 refrigerant and R134a "retrofits". Energy savings up to 30%.

* Compatibility: Compatible with most common refrigeration materials and lubricants including R134a, R12, metal components, mineral and synthetic(Ester and PAG) lubricants, seals, gaskets, hoses, compressors, and o-rings.

* Environment: 100% natural organic refrigerant, non-ozone depleting, non-global warming. 12a is in full compliance with the UN Montreal Protocol.

* Safety: Does not become caustic when contaminated with moisture or oxygen. Non-toxic, non-carcinogen, autoignition temperature above 1385F. No long term health risks have been attributed to RED TEK® 12a refrigerant.
"

 

I am surprised to know that R134a is illegal in your country. Which country is that? Frequently this is political, e.g. no production facility for R134a.

To be exact, R134a is not as good as the R12 (original CFC type, not R12a HC) it replaced as for cooling properties but it is less harmful to the environment.

The R12a manufacturers all claim good benefits. This product didn't make the cut 20 years ago mainly due to flammability issues. You can imagine what happens when it leaks out.