[dreamingmuscle]

I'm new pontiac GTO owner so pardon some silly questions. My 68 GTO has A/C but most of the stuff in front of the fire wall is missing. I found a doner in a 70 Lemans and retrieved most of the brackets and compresure. Reading this collum has me a little confused though. What is a poa valve and a expansion valve and where are they found. When removing the parts I didn't see any thing else to remove from the car except the condencer, receiver drier and the firewall parts.
One more thing I wasn't able to get the pullys are these a add on to the existing pullys or another set up completly. the car does have power steering. Any one have a good diagram of these parts and how they go together my manuals don't show them. What manual has the A/C system in it. I'll buy it if I can find it.

Thanks Glen

Finally got my dream car and can't get it out of the garage.

[dreamingmuscle]

I'm new pontiac GTO owner so pardon some silly questions. My 68 GTO has A/C but most of the stuff in front of the fire wall is missing. I found a doner in a 70 Lemans and retrieved most of the brackets and compresure. Reading this collum has me a little confused though. What is a poa valve and a expansion valve and where are they found. When removing the parts I didn't see any thing else to remove from the car except the condencer, receiver drier and the firewall parts.
One more thing I wasn't able to get the pullys are these a add on to the existing pullys or another set up completly. the car does have power steering. Any one have a good diagram of these parts and how they go together my manuals don't show them. What manual has the A/C system in it. I'll buy it if I can find it.

Thanks Glen

Finally got my dream car and can't get it out of the garage.

[engineer]

Service manual or the restoration guide shows the AC system. Even Chiltons shows the basic setup and describes the operation of POA and expansion valves.

[MarkJ]

The expansion valve is located below the POA valve and it controls refrigerant flow into the evaporator.

When refrigerant reaches the expansion valve, it is a high pressure liquid. The expansion valve admits a metered amount of refrigerant into the evaporator. The refrigerant pressure is also lowered as it enters the evaporator. The expansion valve has a thin capillary tube connected to a temperature bulb that exists from the top of the circular diaphragm.

The POA (pilot operated absolute) valve controls evaporator pressure, and allows the evaporator temperature to drop as low as possible without freezing. This valve is mounted near the top of the evaporator and has an equalizer line connected to the expansion valve.

The POA valve will have a Schrader valve on it for charging the system. This is the “low” (i.e. low pressure gas) side of the system.