AC works, but not efficient - not very cool at max. Low side 80 psi, high side 200 psi at ambient temp F 83 degree. (I have ac manifold gauge)
No leak visually. Compressor assembly works.

The ac never has been very cool in my memory.

Please advise what is the official pressures should be; how many oz of refrigent and lubricant needed if I refill after recyled.

May I adjust some parts to lower the suction pressure.

Thank you in advance.

 

Low side should be 40 PSI or less. Hi can be ranged from 150PSI to 400 PSI. don't really matter.

Did you charged the A/C system? maybe it is over charged?

the Weight of R134a in the system is on the sticker under the hood. Just hunt for it either on the Top Radiator support or under the hood. Usually I just add an Oz of oil when I recharge the system after service. more if parts are being replaced.

If the charge weight is right, usually a 'too high' pressure on Lo side indicate a bad compressor.

btw, you have a 4 banger or V6? they have different style compressor. And 80 PSI on the 4 banger could be normal 'sometimes'.

 

It is sxt model and 3.5 V6. It has not been recharged since new bought. And the ac never has been very cool in my memory.

While I recharged my another vehicle and hooked up the pressure gauge, I got the readings of this Journey suv by the way, but not charge it.

Theoretically, low and high side should be around 45/225 psi at temp 83 degree.

Over charged should be high on both low and high sides which is not my case.

I think it might be either bad compressor or expansion valve. Anyone knows where is the expansion valve?

 

Well, Then there goes your hope if it being cheap wrongful charged issue.

With rear A/C it is 32 oz. without rear A/C would be 20 oz.

Every car should have a sticker on it, be it 2012 or 1992.

 

I doubt it is the over-charge issue, while more apt to valve or compressor faults.

As duel ac, does truning off rear ac will affect the pressure readings and efficient of the front ac?

I am still looking for where the expansion valve locates. Anyone may help?

 

Today, I took temp reading, the vent temp was 50 degree F at amb temp 85. Anyyone has any advices?

 

a 35 degree drop... that sounds normal, actually.
But I still don't think you should get 80 PSI on low side. Maybe the problem is your gauge is broken.

 

You really need to know for SURE how much freon is in there. That is your base starting point.

 

50 degree discharge air on a 83 degree day sounds pretty darn good to me.

 

This vehicle is very sensitive to the correct charge. I accidentally over-charged mine and if the outside temperature was over 90 degrees the air actually seemed to quit working. It would just blow warm and humid air when on. The rear quit blowing cold at any ambient temperature. I got the right gauges and the correct charge numbers, adjusted everything accordingly, then the front and rear AC worked as it should and keeps the car nice and cool even in 110+ degree weather here in Phoenix AZ.

With that said, the expansion valve IIRC is on the left side (looking at the front of the vehicle) between the engine and inside fender. Just follow the AC lines from the left side firewall behind the engine out towards the front and you should see it.