Handful of A/C questions......

[gotta240]

The a/c on my 240 is not working well. So, i have a few questions

1. I bypassed the heater core because it was leaking, leaving a pool of water inside my car, on the passenger side. The a/c system has NOTHING to do with me bypassing the heater core, DOES IT?

2. Are you supposed to check the a/c pressure with the a/c ON or OFF? I checked the low side with the car OFF, and the pressure was 100psi.(is that ok?)

3. What is the alluminum cylinder close to the PASSENGER SIDE of the radiator. It is aprox 7 inches tall, and 4 inches wide. It has a line going in and out of the top of it, has a r134a sticker on it, and appears to have a sensor sticking out of the top of it.. WHAT IS THE CYLINDER THING, and what does it do?

When i bought the car, the guy gave me A NEW CYLINDER piece as described above.. I'm wondering if that is the cause of the a/c problems... If so, how can that be replaced safely? Should i drain the a/c system BEFORE replacing it?
thanks a lot guys!
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[projectRDM]

Heater core has no affect on cooling.

Cylinder thing = drier. Replacing it will more than likely solve your cooling issues if the guy gave it to you to install.

Read the FSM and talk to a competent A/C repair specialist before going any further unless you like to throw money away and choke to death.

[hipro]

1. I bypassed the heater core because it was leaking, leaving a pool of water inside my car, on the passenger side. The a/c system has NOTHING to do with me bypassing the heater core, DOES IT?

As stated earlier, no! The heater core has water routed thru it; the A/C evaporator has the compressed liquid inside that is vaporized (thus the name evaporator) - this phase change from liquid to vapor occurs across an expansion valve but also requires heat, which is pulled from the air, thus resulting in the lowered air temperature.

2. Are you supposed to check the a/c pressure with the a/c ON or OFF? I checked the low side with the car OFF, and the pressure was 100psi.(is that ok?)

FSM says running and idling at 1500 rpm, with fan speed at max, recirc on, and max cold temp selected. Plus, allow system to operate at least 10 minutes before testing. The normal suction side (low side) pressure should only be around 25 psi; if you sensed 100 psi, you probably were on the high side piping (smaller lines, toward the front of the car, thru the condenser, back thru the liquid tank, and to the evaporator). It is inside the evaporator, after passing thru the expansion valve, that the pressure is reduced. Normal high side pressure is around 110, depending on ambient temperature.

3. What is the alluminum cylinder close to the PASSENGER SIDE of the radiator. It is aprox 7 inches tall, and 4 inches wide. It has a line going in and out of the top of it, has a r134a sticker on it, and appears to have a sensor sticking out of the top of it.. WHAT IS THE CYLINDER THING, and what does it do?

Liquid tank, some people call a drier, but it is more of a liquid/vapor separator. It is desgined to ensure liquid gets passed thru to the evaporator because the phase change from liquid to gas removes the heat to provide the cooling effect.

When i bought the car, the guy gave me A NEW CYLINDER piece as described above.. I'm wondering if that is the cause of the a/c problems... If so, how can that be replaced safely? Should i drain the a/c system BEFORE replacing it?

To replace any of the components (compressor, liquid tank, evaporator, condenser, hard lines, etc.) the system has to be "broken" and the gas will escape. Laws require that the refrigerant be collected and not released to the atmosphere (requires a vacuum pump).

[gotta240]

HIPRO- thank you! Best reply ever.

so where is the low side to be found? I pulled the reading from the port nearest the compressor on the drivers side. Also, does a bad "dryer" affect the cooling of an ac dramatically, or is it just an extra helP?
thanks again.