AC system too much pressure

[DemoFly]

We noticed that our Toyota Echo's AC wasn't blowing cold air, but actually hotter air than ambient.

I bought an AC recharge kit, and the low side reading of the AC system read almost 90PSI.

What do I do?

 

[Quest]

you mean you already tried recharging yourself?

90psi on the low side is too much. You'll have to find a proper means to rectify the problem by means of having your system fully evacuated (deep-vacuum) to verify the mechanical condition and then recharge with proper amount of refrigerant.

Q.

 

[DemoFly]

All I have done is put the R134a gauge on the low side port and it read about 87psi. I have not done anything else.

 

[stroked93]

if the compressor is not running the pressure will equalize. check with compressor running

 

[DemoFly]

I can't tell if the compressor is running or not, the car has been idling with the AC on for about 30 minutes and both the low and high pressure sides are very hot to the touch.

I went ahead and shut everything off.

 

[Quest]

check to see if your compressor manage to engage when engine is running (assuming that there' still some residual refrigerant left and the system and the system is still "sound"). If not engaging, check fuse to ensure that your compressor clutch is indeed functional.

also: if possible, get a set of hi-low pressure gauge and measure both the hi side and the low side pressure while A/C engaged and engine running. If both high side and low side pressure reading seems to be the same, your compressor is prolly faulty.

Q.

 

[AVB]

See if the pressure is the same with the car off. It probably will be, if it is the system is probably properly charged. If that is the case you may have a electrical issue could be as simple as a disconnected wire at the clutch.

 

[mechtech2]

It actually may be too low!
90 is correct if the ambient temps are about 90 deg F.
But that is at rest, when the engine compartment is not heated up.
Rest pressure in a heated environment will be higher.
I need to know EXACTLY every extant condition when this reading was taken.