C-3, AC drier (accumulator)

[Dick W.]

Re: C-3, AC drier (accumulator)

Screen is in the bottom of the expansion valve. Be very careful when removing the valve. It is easy to ruin the evaporator when the nut and the tubing turn together. Soak the fitting for several hours with a good penetrating oil. Be sure to use a wrench to hold the valve when attempting to loosen the nut. Good luck and Happy Thanksgiving to all

[Dick W.]

Re: C-3, AC drier (accumulator)

Screen is in the bottom of the expansion valve. Be very careful when removing the valve. It is easy to ruin the evaporator when the nut and the tubing turn together. Soak the fitting for several hours with a good penetrating oil. Be sure to use a wrench to hold the valve when attempting to loosen the nut. Good luck and Happy Thanksgiving to all

[Jim T.]

Re: C-3, AC drier (accumulator)

John, you certainly want unrestricted flow of R12 to keep you cool in TX. My 70 did well in Dallas the five years I lived there. If you remove the metal screen without damage, it can be reused. This metal screen is funnel shaped and real small, you will see that it does not take very much desiccant particles to clog it. I bought a new one at a local auto parts store, but this was in 1988. NAPA might have the little screen. The difficulty in removing the condensor line connection to the expansion valve with the optional 454 engine could be more difficult that with the 350. The expansion valve is the device that has a line coming out of the top of it that has the capillary bulb. The bulb has insulating type of wrapping around it keeping it in place on a aluminum pipe that comes out of the top of the air conditioning housing. The expansion valve is located in front of the air conditioning housing and is mounted right next to the POA valve. Don't know what is the best to use to flush the lines, I am sure there is a liquid to use to remove desiccant particles. An auto parts store like NAPA may carry it to supply their auto shop parts customers.

[Jim T.]

Re: C-3, AC drier (accumulator)

John, you certainly want unrestricted flow of R12 to keep you cool in TX. My 70 did well in Dallas the five years I lived there. If you remove the metal screen without damage, it can be reused. This metal screen is funnel shaped and real small, you will see that it does not take very much desiccant particles to clog it. I bought a new one at a local auto parts store, but this was in 1988. NAPA might have the little screen. The difficulty in removing the condensor line connection to the expansion valve with the optional 454 engine could be more difficult that with the 350. The expansion valve is the device that has a line coming out of the top of it that has the capillary bulb. The bulb has insulating type of wrapping around it keeping it in place on a aluminum pipe that comes out of the top of the air conditioning housing. The expansion valve is located in front of the air conditioning housing and is mounted right next to the POA valve. Don't know what is the best to use to flush the lines, I am sure there is a liquid to use to remove desiccant particles. An auto parts store like NAPA may carry it to supply their auto shop parts customers.

[D S.]

Re: C-3, AC drier (accumulator)

Thanks, Jim. I'm certainly getting a lot of sound advice from so very well informed folks here and I'm saving it all. Certainly there are others who might be interested in this invaluable information. When I had to replace a heater hose recently it became apparent I couldn't possibly do it from the topside due to the overflow tank and hoses and tubes and fat engine. So, I put it on a rack, removed the rocker molding, and the splash shield. Much easier access with some extra work. It looks like I may be doing that procedure again but it may well be worth it again. I like having everything working although some might question why one would want to run AC on a 454 convertible. You know they get great gas mileage (joke).

[D S.]

Re: C-3, AC drier (accumulator)

Thanks, Jim. I'm certainly getting a lot of sound advice from so very well informed folks here and I'm saving it all. Certainly there are others who might be interested in this invaluable information. When I had to replace a heater hose recently it became apparent I couldn't possibly do it from the topside due to the overflow tank and hoses and tubes and fat engine. So, I put it on a rack, removed the rocker molding, and the splash shield. Much easier access with some extra work. It looks like I may be doing that procedure again but it may well be worth it again. I like having everything working although some might question why one would want to run AC on a 454 convertible. You know they get great gas mileage (joke).

[Dick W.]

Re: C-3, AC drier (accumulator)

Use a commercially available flush for the system. If the dessicant bag has ruptured, you will need to remove the lines from the condenser and blow it out thoroughly. The bottom of it is the lowest point in the system and collects the debris. If you have a commercial refrigeration shop close by, after you have done all the flushing and cleaning, take the car there and get them to evacuate the system, fill with DRY nitrogen, and then evacuate the system again. The dry nitrogen will remove ALL the moisture that has accumulated in the system while it was open.

[Dick W.]

Re: C-3, AC drier (accumulator)

Use a commercially available flush for the system. If the dessicant bag has ruptured, you will need to remove the lines from the condenser and blow it out thoroughly. The bottom of it is the lowest point in the system and collects the debris. If you have a commercial refrigeration shop close by, after you have done all the flushing and cleaning, take the car there and get them to evacuate the system, fill with DRY nitrogen, and then evacuate the system again. The dry nitrogen will remove ALL the moisture that has accumulated in the system while it was open.

[William H.]

Re: C-3, AC drier (accumulator)

Hello Scott,
The line between dryer and evaperator should not be cold or wet. This is ambient temperature liquid fron at this point that has just been cooled/condensed from the condensor. IT then goes to the expansion valve and is allowed to expand. Then in the evaperator it takes the heat from the inside air and returns to be recompressed in the compressor and the heat is given back off as the gas condesnses back to a liquid in the condensor. The evaperator and the return line to the compressor should be cold/ cool but not the line between the dryer and the expansion valve this indicates that the liquid is turning to a gas in the dryer or the line to the expansion valve. IT could also be that there is not enough airflow through the evaperator case. In any case It souns like there is a malfunction in the system could be POA valve or Expansion valve as well. You might want to have the drier rebuilt and then have the entire system flushed and evacuated as well. I have flushed later model systems with orifice tunbes instead of Expansion/ poa valves and used the car wash and then lots of clear water and then blow out with clean compressed air. Then when you evacuate it just leave it below 27" mercury for overnight this will boil all of the moisture out of the sytem and remove it. However I am not at all sure that this is ok on these older systems. Hopefully someone with more experience in that area will chime in. Good luck!
Bill

[William H.]

Re: C-3, AC drier (accumulator)

Hello Scott,
The line between dryer and evaperator should not be cold or wet. This is ambient temperature liquid fron at this point that has just been cooled/condensed from the condensor. IT then goes to the expansion valve and is allowed to expand. Then in the evaperator it takes the heat from the inside air and returns to be recompressed in the compressor and the heat is given back off as the gas condesnses back to a liquid in the condensor. The evaperator and the return line to the compressor should be cold/ cool but not the line between the dryer and the expansion valve this indicates that the liquid is turning to a gas in the dryer or the line to the expansion valve. IT could also be that there is not enough airflow through the evaperator case. In any case It souns like there is a malfunction in the system could be POA valve or Expansion valve as well. You might want to have the drier rebuilt and then have the entire system flushed and evacuated as well. I have flushed later model systems with orifice tunbes instead of Expansion/ poa valves and used the car wash and then lots of clear water and then blow out with clean compressed air. Then when you evacuate it just leave it below 27" mercury for overnight this will boil all of the moisture out of the sytem and remove it. However I am not at all sure that this is ok on these older systems. Hopefully someone with more experience in that area will chime in. Good luck!
Bill

[Jim T.]

Re: C-3, AC drier (accumulator)

Scott another item to remove for access is the side grille on your 70. Two screws at the top and from underneath, one small nut (3/8 or 7/16 don't remember) that is easy enough to remove and you can remove the grille. Be patient, the bottom of the grille will have the long bolt/stud that is fixed in the grille. Gently/carefully tilt the grill at the top and lift it out. Using a mirror you can see the nut on the stud when sitting beside the grille and you will not have to get under the car to remove it using an socket with extension.

[Jim T.]

Re: C-3, AC drier (accumulator)

Scott another item to remove for access is the side grille on your 70. Two screws at the top and from underneath, one small nut (3/8 or 7/16 don't remember) that is easy enough to remove and you can remove the grille. Be patient, the bottom of the grille will have the long bolt/stud that is fixed in the grille. Gently/carefully tilt the grill at the top and lift it out. Using a mirror you can see the nut on the stud when sitting beside the grille and you will not have to get under the car to remove it using an socket with extension.

[D S.]

Re: C-3, AC drier (accumulator)

Thanks, Jim. That was another problem I encountered. Because the engine is wider the AC compressor, manifold, and refrigerant lines are moved closer to the inner fender. Then the long recovery tank has a heater hose attached to the bottom of the tank and the other hose to the heater valve nearby. The POA valve sytem adds more barriers. All that busy work is difficult to maneuver my hands through and I don't have small hands. I studied that alternative and made some attempts to reach the inside of the side grille from the top. I even took the straps off the tank but getting to the heater hose clamps from the top was almost impossible.

[D S.]

Re: C-3, AC drier (accumulator)

Thanks, Jim. That was another problem I encountered. Because the engine is wider the AC compressor, manifold, and refrigerant lines are moved closer to the inner fender. Then the long recovery tank has a heater hose attached to the bottom of the tank and the other hose to the heater valve nearby. The POA valve sytem adds more barriers. All that busy work is difficult to maneuver my hands through and I don't have small hands. I studied that alternative and made some attempts to reach the inside of the side grille from the top. I even took the straps off the tank but getting to the heater hose clamps from the top was almost impossible.