need C2 (1966) A/C Experts Please

[BOB LOVETT]

Re: need C2 (1966) A/C Experts Please

Thanks Guys...

I'm running R12, not sure about the oil thing. I will check with the fellow that charged the system. I assume if the oil has been "crossed" when the system is "evacuated" that would remove all of the oil as well. Could you explain "the hose clamped hoses reversed" that you wrote?....not sure what you meant. As for the brass water valve & vacuum switch, both have been replaced but as we know, that doesn't mean that they work. The system has been "evacuated" so to check the brass water valve I believe that by disconnecting the electrical to the compressor & pulling out the control knob for the A/C I should be able to check the water flow to the heater box & see if the hoses are cool.....as for the POA it was purchased from Classic Auto Air in Tampa FL. invoice states its 15-51 R-12>> FYI:$155.00.

[BOB LOVETT]

Re: need C2 (1966) A/C Experts Please

Thanks Guys...

I'm running R12, not sure about the oil thing. I will check with the fellow that charged the system. I assume if the oil has been "crossed" when the system is "evacuated" that would remove all of the oil as well. Could you explain "the hose clamped hoses reversed" that you wrote?....not sure what you meant. As for the brass water valve & vacuum switch, both have been replaced but as we know, that doesn't mean that they work. The system has been "evacuated" so to check the brass water valve I believe that by disconnecting the electrical to the compressor & pulling out the control knob for the A/C I should be able to check the water flow to the heater box & see if the hoses are cool.....as for the POA it was purchased from Classic Auto Air in Tampa FL. invoice states its 15-51 R-12>> FYI:$155.00.

[Jack H.]

Re: need C2 (1966) A/C Experts Please

Simply evacuating the system does NOT remove oil... Residual oil will remain in the compressor, evaporator, condensor and receiver/dryer. Your copy of the Chassis Service Manual tells you how much oil goes in each component, presuming fresh/dry replacements are being installed.

To FULLY purge a system of its prior oil, you have to go one component at a time to empty it and/or 'flush' it out using compressed air. Then, when each component is now freshly purged and dry, re-fill each with the amount of oil called for in the Chassis Service Manual before you reconnect the system, pull vacuum and fill with refrigerant.

[Jack H.]

Re: need C2 (1966) A/C Experts Please

Simply evacuating the system does NOT remove oil... Residual oil will remain in the compressor, evaporator, condensor and receiver/dryer. Your copy of the Chassis Service Manual tells you how much oil goes in each component, presuming fresh/dry replacements are being installed.

To FULLY purge a system of its prior oil, you have to go one component at a time to empty it and/or 'flush' it out using compressed air. Then, when each component is now freshly purged and dry, re-fill each with the amount of oil called for in the Chassis Service Manual before you reconnect the system, pull vacuum and fill with refrigerant.

[Larry M.]

Re: need C2 (1966) A/C Experts Please

Bob:

The knob that pulls out and activates the AC compressor (and also moves a door inside the AC/heater box) is labeled AIR COND. PULL. This knob is a different one than the knob I mentioned earlier that controls the vacuum to the heater water valve (and also moves another door inside the AC/heater box). The knob that I refered to in my earlier reply to you is labeled COOL-IN/HOT-PULL. As a matter of fact, all four of the knobs associated with your air conditioning system have a "PULL function" that affects some part of your air conditioning system operation and performance.

Use the COOL-IN/HOT-PULL knob function to check whether the heater water control valve is shutting off properly. When you pull this knob out, vacuum is applied to this valve causing it to open and let hot coolant flow through your heater core. When you push this knob back in, it shuts off the vacuum source to the valve which should cause the valve to close and shut off hot coolant to the heater. You can also simply pull off the rubber vacuum hose to the heater water valve, which should cause it to close; but this only checks the valve and not the combination valve/vacuum switch operation. When you want maximum air conditioning and cooling, you do not want to have hot coolant flowing through your heater core at the same time.

Figure 36 on page 1A-24 of the 1967 Chevrolet Chassis Service Manual has an excellent schematic of the Corvette air conditioning-heater system. There should be something similar in the 1966 Chassis Service Manual. Figure 36 shows the four AC control knobs, their functions, the air doors inside the AC/heater box that the knobs control, and the various switches that the knobs also control.

Larry

[Larry M.]

Re: need C2 (1966) A/C Experts Please

Bob:

The knob that pulls out and activates the AC compressor (and also moves a door inside the AC/heater box) is labeled AIR COND. PULL. This knob is a different one than the knob I mentioned earlier that controls the vacuum to the heater water valve (and also moves another door inside the AC/heater box). The knob that I refered to in my earlier reply to you is labeled COOL-IN/HOT-PULL. As a matter of fact, all four of the knobs associated with your air conditioning system have a "PULL function" that affects some part of your air conditioning system operation and performance.

Use the COOL-IN/HOT-PULL knob function to check whether the heater water control valve is shutting off properly. When you pull this knob out, vacuum is applied to this valve causing it to open and let hot coolant flow through your heater core. When you push this knob back in, it shuts off the vacuum source to the valve which should cause the valve to close and shut off hot coolant to the heater. You can also simply pull off the rubber vacuum hose to the heater water valve, which should cause it to close; but this only checks the valve and not the combination valve/vacuum switch operation. When you want maximum air conditioning and cooling, you do not want to have hot coolant flowing through your heater core at the same time.

Figure 36 on page 1A-24 of the 1967 Chevrolet Chassis Service Manual has an excellent schematic of the Corvette air conditioning-heater system. There should be something similar in the 1966 Chassis Service Manual. Figure 36 shows the four AC control knobs, their functions, the air doors inside the AC/heater box that the knobs control, and the various switches that the knobs also control.

Larry

[BOB LOVETT]

Re: need C2 (1966) A/C Experts Please

thanks Jack

[BOB LOVETT]

Re: need C2 (1966) A/C Experts Please

thanks Jack

[BOB LOVETT]

Re: need C2 (1966) A/C Experts Please

Thanks Larry.....I do have the 1966 Manual.....I think what I should do first which sounds simple, is to check the valve & make sure that it is operating correctly............and then go from there.....don't really what to get into the evaporator thing if I don't have to...

[BOB LOVETT]

Re: need C2 (1966) A/C Experts Please

Thanks Larry.....I do have the 1966 Manual.....I think what I should do first which sounds simple, is to check the valve & make sure that it is operating correctly............and then go from there.....don't really what to get into the evaporator thing if I don't have to...

[BOB LOVETT]

Re: need C2 (1966) A/C Experts Please

Thanks Larry.....I do have the 1966 Manual.....I think what I should do first which sounds simple, is to check the valve & make sure that it is operating correctly............and then go from there.....don't really what to get into the evaporator thing if I don't have to...

[BOB LOVETT]

Re: need C2 (1966) A/C Experts Please

Thanks Larry.....I do have the 1966 Manual.....I think what I should do first which sounds simple, is to check the valve & make sure that it is operating correctly............and then go from there.....don't really what to get into the evaporator thing if I don't have to...