Low Pressure Port 64 Air Conditioning???

[Daniel M.]

Hi Guys,
Wondering If Anyone Can Tell Me Which Is The Low Pressure Port On The Compressor Of My 1964. There Are Two(2) Ports At The Back Side Of The Compressor Which Appear (almost) Identical. Dont Want To Try And Charge The Wrong Side.
I Also Found Another Port Closer To The Firewall On A Part Other Than The Compressor?

Thanks In Advance
Dan

[Wayne M.]

Re: Low Pressure Port 64 Air Conditioning???

Hi Guys,
Wondering If Anyone Can Tell Me Which Is The Low Pressure Port On The Compressor Of My 1964. There Are Two(2) Ports At The Back Side Of The Compressor Which Appear (almost) Identical. Dont Want To Try And Charge The Wrong Side.
I Also Found Another Port Closer To The Firewall On A Part Other Than The Compressor? ...

Daniel -- the high pressure port is the one with the muffler, which is the outboard side. This continues to the top of the condenser. Low pressure port is the other one (inboard).

The third connection that you've found is probably on the STV (Suction Throttling Valve), mounted vertically and above the expansion valve (smaller and horizontal) and is used to adjust the evaporator pressure (to 33 psi target, using the low pressure gauge).

[Daniel M.]

Re: Low Pressure Port 64 Air Conditioning???

Thanks Wayne,
I Tried To Search The Web For Diagrams Or Schematics Of The A/c System To No Avail. Hard To Imagine This Info Is So Hard To Find?
Dan

[Domenic T.]

Re: Low Pressure Port 64 Air Conditioning???

Daniel,

A good rule of thumb is that the high pressure line is always smaller than the low pressure line.

DOM

[Daniel M.]

Re: Low Pressure Port 64 Air Conditioning???

Thanks Dom!!!!

[Terry M.]

Re: Low Pressure Port 64 Air Conditioning???

Thanks Wayne,
I Tried To Search The Web For Diagrams Or Schematics Of The A/c System To No Avail. Hard To Imagine This Info Is So Hard To Find?
Dan

It is actually not hard to understand at all when you consider the style of AC system on your 1964 has not been made in almost 50 years. Knowing it is called a Suction Throttling Valve system might have helped, but the best source for information specifically about your 1964 Corvette is the 1964 Corvette Service Manual. If memory serves you have to buy the 1963 Service manual and the 1964 Supplement, but the friendly folks at the NCRS Store (click the "NCRS Store" button on the blue bar at the top of the page) will fix you right up with all the information you could ever want about your baby. I know books are so old school, but in this case they are the best.