Ac system won’t equalize pressure.

[Stewartkyle44]

@LouNY Yesterday it sat for more than an hour while I was researching stuff with engine off in about 80 degree temps outside the low side was 75psi and high side at 25psi. When the system settles that where it sits at.

 

[LittleBill21]

system should settle evenly, you sound like there is an obstruction somewhere in the system

 

[Stewartkyle44]

@LittleBill21 That is the only thing I can think of being the issue. Where could the obstruction be though? I pulled the low and high tube off the back of the compressor after evacuating and forced compressed air through the lines and could feel it coming out the other end.

 

[Stewartkyle44]

Maybe it’s something in the actual AC unit?

 

[LittleBill21]

could be in the cores or orifice valve, does your system have a dryer? was it replaced properly. blowing off the pressure valve definitely indicates some kind of high pressure that should not be there.

if you removed the suction side of the compressor, do you get a INSTANT release and equalization? if not you have issues up near the dryer evaporator or metering device.

 

[LittleBill21]

my uneducated opinion says its not the compressor, if the pressure is still uneven after sitting. i'd be looking at the orifice metering component, as its the smallest section in the system that could get clogged.

Feel like this would be a good place to use my thermal camera.

 

[Stewartkyle44]

@LittleBill21 The shop manual doesn’t say anything about the orifice valve. I don’t think it has one just the expansion valve which I replaced. It does have a dryer and I replaced that. I can’t remove just the suction side of compressor line as the low and high side lines use a special bracket that you have to mount or remove them at the same time.

 

[LittleBill21]

I'm only guessing at this point, since I can't see it, I understand about the bracket. maybe you can borrow a thermal camera, and see if you can see if there is a block somewhere in the cores.

 

[workinonit]

I've never seen one go to ambient with that much pressure difference. Even if you had a blockage it should equalize in the other direction. Almost sounds like a check valve is in backwards but I don't know what that would be unless the TXV is backwards. It's really strange that the suction pressure is higher than the discharge pressure.

 

[LittleBill21]

I've never seen one go to ambient with that much pressure difference. Even if you had a blockage it should equalize in the other direction. Almost sounds like a check valve is in backwards but I don't know what that would be unless the TXV is backwards. It's really strange that the suction pressure is higher than the discharge pressure.

i would agree he put it together wrong, other then the fact he was blowing pressure valves clean off before he started replacing things.