A/C pressure question

[79elcamino]

i have a 06 nissan sentra, does anyone know where to find how much pressure for high and low side should be in a cars A/C system?

[CHzo6]

Re: A/C pressure question

Low side is typically around 30-50 psi, with the high side being in the hundreds. What is the problem?

[79elcamino]

Re: A/C pressure question

When u put ur hand to the vents the air is nice and cold but by the time is reaches u it's not, on really hot days the cabin does not get cooled off, I put a thermometer inside the vents and it read 45 degrees and stayed there, my mechanic said it should be at 40, I was just thinking maybe I'm a little low of freon cause like I said on those 95 degree days the cabin doesn't get cool, but in other peoples cars there cabin gets cool.

[Mark58]

Re: A/C pressure question

They sell small kit that include 1 pt of freon with the GO/NO GO gauge at Autozone or any auto supplier.

[79elcamino]

Re: A/C pressure question

I never added freon to a car ac before I'd rather a pro to do cause I know if u add to much u could do series damage and what's the go/no go gauge?

[Alyon]

Re: A/C pressure question

If you have a sight glass, especially Sentra is TXV type A/c system, check if you have bubbles or foamy, signs of low freon. It should be clear. Sightglass is usually located above the reciever dryer. If it is low, take it to the shop. Let them recover the freon, evacuate the whole system from all the moisture and gas (remember, unwanted gas in the system should be less than 2% and it should be pure R134A) and recharge it with freon. Also check your condenser, maybe it's full of bugs. And also check your condenser fan if it is working. And also sometimes, the A/c system is working good, but the mode doors (doors that shifts the wind direction of the vents), recirulating doors are not working properly. I would not advise putting freon by yourself because there will be chance of overloading that could damage the compressor and lessen the cooling capacity of the car. Also ask the shop to inject dye on it to trace the source of leaks. Hope this helps.

[CHzo6]

Re: A/C pressure question

Your car should have R134a and it is very easy to check and "recharge" those systems with a kit from an autoparts store, which is what it sounds like it needs.

[MadCow]

Re: A/C pressure question

You haven't mentioned anything about a cabin air filter, check that first before you take it to a shop or try to service the system yourself!

[79elcamino]

Re: A/C pressure question

You haven't mentioned anything about a cabin air filter, check that first before you take it to a shop or try to service the system yourself!

i replaced that about last summer and it didnt help

[79elcamino]

Re: A/C pressure question

So I had the AC system recovered and recharge the mechanic skipped the step that removes the oil, he said s not necessary. He said that only time the oil is changed is when you buy a new compressor. Should he have done it and when he was done the machine wanted to equalize all hoses he skipped that step to and started the car and put AC on then let me leave, should he have equalized the hoses?