No cold air 2002 Nissan sentra GXE 1.8L

[0utThere]

The clutch engages when i turn on the AC, 79 degrees out. worked fine before i replaced the head gasket.

low side engine off


high side engine off


engine running

[tbirdtbird]

More info.
Was any of the AC system disturbed when the gasket was changed, anything at all?
Readings with engine off and at idle carry little meaning, we need pressures at 1800 RPM, windows down, max fan, max cool
It almost appears the couplers have not depressed the schrader cores, the gauges read about ambient pressures with "engine running" but we do not know the RPM

[JohnHere]

As suggested, double-check your Manifold Gauge Set connections and valves. If they're correct and the adapter thumb-wheels are in the fully-clockwise open position, the static pressures (measured with the engine off) suggest that you have virtually no refrigerant remaining in the system.

Are you sure that the clutch is actually engaging and that the compressor shaft is rotating, not just the clutch outer pulley?

[0utThere]

tbirdtbird, johnhere i had to undo the mount for the alternator which shares the same belt with the AC compressor. I tried to put the fan assembly for the rad in backwards and i pushed the rubber hose down a bit for the high side discharge from the evaporator out side of that ......? the outer clutch plate starts turning when i turn on the AC , how can i tell if the compressor is turning? isn't there a pressure sensor when the coolant pressure is low turns off the comressor?

so there is a tool with the manifold set to turn the schrader valve, should i try turning the shradder valve in the couplers out a bit? it was cool out today and i noticed warm air coming out the vents when on AC , could turn to heat and got blasted with hot air , maybe its a vaccuum issue with the blend doors i had to take the manifold off although when switched to heat i do get very hot air. i do not hear any air leaks under the hood, i did have an issue sort of like this with a 2003 Impala had a vaccuum storage tank in the dash that was leaking was not AC related was the blend doors though HVAC worked just not the doors.

[tbirdtbird]

" how can i tell if the compressor is turning?"
By looking closely at the pulley with the compressor both on and off and compare.

When you disturbed that hose you disturbed the seal, and your system slowly leaked down to nothing.
The good news is that if you remove that hose fitting, and place a new O-ring seal, and have someone vacuum down the system and recharge by the amount specified on the label under the hood, it will be an easy repair and you will have your AC back.
You can get a small tube of the proper oil to put on the O-ring from the same place you buy the O-Rings. It sounds like you need a number 10 O-ring. A pic of the hose you disturbed at the fitting will tell us just what size you need.
Look carefully at the region of the disturbed hose, no doubt you will see some areas wet looking with compressor oil, if so, you will need to have your tech pay attention to that, he may have to add some oil.

Tim, the site sponsor, will no doubt have the orings and oil you need at the parent website, ackits.com

[0utThere]

tbirdtbird i went out this morning and hooked up the manifold set again and w/ the engine running the pressure was zero low side as you stated it would be. i had not read this post yet . i put in a 1 lb can of R134a ...they are selling them for $2.50 at walmart right now so i thought what the heck. they are the new cans with the seal.so i thought it was worth the try. it is ice cold air now , not sure if air leaked in. I had the quick connect type of couplers on the ends of the manifold and replaced them with the valve type. i think when i turn the valves in the open direction it pushes down on the port shrader valve?...maybe the first time i did not have the shrader vale depressed on the low side. if it does have air the system what is the symptoms...freezing? i can always go and have the system evacuated at a shop i suppose.
how does the AC in the winter time when the AC compressor runs for short burst when you have the heat on how does that dry out the hot air?

[B52bombardier1]

Cold air does not hold as much moisture as warm air so the air sheds its water and becomes dry. With the AC set to defrost, the chilled AC air is dryer than the moisture on the windshield glass and the blowing air basically pulls the moisture off the glass as it blows over.

Rick

[tbirdtbird]

Your original refrigerant charge leaked out of the fitting you disturbed, thus I'd expect the 134 you just put in to do the same over the next couple of days. Time to go back and re-read my post.
There is no way to know if air got in the system, which is why you have to re-seal the disturbed fitting, vacuum down, and recharge to the correct weight on the under hood sticker. When you re-seal the disturbed fitting, you will be opening the system to air anyway, so the advice stands.
If there is air in the system, the high side can read higher than it should, and performance will be reduced. It won't cause freezing.
You have an easily corrected problem, which can only get worse (and expensive) if the system gets hacked.

It always amazes me that posters will write in and then completely overlook the advice given

[Cusser]

It always amazes me that posters will write in and then completely overlook the advice given

Seems to happen a lot, and on many different forums and groups...

[Tim]

Tim, the site sponsor, will no doubt have the orings and oil you need at the parent website, ackits.com

This is true and not true.

ACKits.com has o-ring master boxes. Just not a "single" o-ring with free freight and next-day delivery.