1957 - Aftermarket AC not cooling

[TbirdFan76]

My 57 T-bird has an aftermarket air conditioner that is not cooling as it should. Once the engine has warmed up to normal temperature or the car has sat out in the sun on a sweltering day the ac blows warm but not hot. I suspect refrigerant needs to be added. The problem is there isn't a label on the compressor listing the correct refrigerant type. It likely is R134A but without a label on the compressor I can't be sure. Maybe one of you have this unit in your Tbird. It looks like this one from NPD, here is a link to the unit I think I have.
NPD Part Number : T-19B968-2A Manufacturer Reference #'s: 19700KRK (R-134a)

I've also attached pictures of the interior unit and compressor in my Tbird. Also, if you have any documentation on it that would be great.

Thanks!

Neal

 

[doug7740]

On the description from the link you provided it states that the refrigerant used in your air conditioning kit is R-134a. Also, the picture of your compressor shows it has R-134a service ports.

doug7740
1955 Thunderbird Blue

 

[74 Harley]

To be honest the best thing you can do is take it to a certified A/C shop. You need a refrigerant tester to determine what is really in it. If it's low, it leaks. The leak should be fixed before you spend the money on refrigerant. What if it's not leaking and has a bad switch?

 

[willcarterdc]

To be honest the best thing you can do is take it to a certified A/C shop. You need a refrigerant tester to determine what is really in it. If it's low, it leaks. The leak should be fixed before you spend the money on refrigerant. What if it's not leaking and has a bad switch?

I’m having a similar issue with the aftermarket a/c in my ‘57. I take it that a general mechanic would not be the best route to go but that a “certified a/c shop” is needed? (I know nothing about a/c systems and therefore don’t have a sense of whether dealing with them is something likely to be within the realm of a good general mechanic shop).

 

[Frankie the Fink]

You would be much better off with an A/C tech, they will know how to identify a leak, test pressures, add refrigerant and not "shotgun" a bunch of unnecessary parts onto the car.....they will also know to evacuate the system if needed.
You COULD do a quick check with the engine running and the A/C on and see if the compressor clutch is cycling as it should be...

 

[74 Harley]

Depending on the state you live in, you can only buy refrigerant if you are certified. I can no longer buy it in Washington...

 

[TbirdFan76]

I could not get the a/c to take in enough refrigerant so took it to a shop. They did the same steps, evacuate the system and add R134a but were able to get it take in 7 ounces of refrigerant. The correct amount for the system is 12 counces. It is cool but not cold. Dye was also added so will be looking for leaks if/when it stops cooling.

Will update as more information becomes known.