A/C capacity

[tonguetalker]

I have a 2000 ford taurus 3.0L DOHC and i have installed a new A/C compressor and i called my local auto parts store for help ha ha. I need to know how much freon this car holds they told me 34 ounces but at that amount it just cycles on and off slowly and is not cold at all. So please help. Thanks

[shorod]

Welcome to the forum!

Well, if you put 34 ounces of Freon in it, that might be part of the problem. You should have used R-134a. Assuming you used R-134a, then may I ask why you changed out the A/C compressor to begin with? Was it because it didn't get cold before? Does the blower motor move air fine, just not cold air? Is the heater control valve shutting off the flow of coolant to the heater core properly? Does the low pressure line get cold from the compressor? Did you evacuate the system before installing the 34 ounces and hold a vacuum on the system for at least 30 minutes to make sure it didn't have any sizeable leaks? Did you also add the appropriate amount of oil to the system?

-Rod

[tonguetalker]

I am a mechanic. I used R-134A the compressor was leaking freon. I changed for that reason also i was told that it held 34 ounces of R-134A. The compressor cycles extremely slow with 34 ounces of R-134A

[shorod]

So I guess many of the questions I asked still hold. I'm not trying to be offensive here, but just because a person is a mechanic does not mean they have the tools (equipment and knowledge) to service the A/C system. You won't have to fire many questions back to me to realize that I don't have the knowledge to service the system properly, but I watched my dad enough to understand that you still need to evacuate the system once you've opened it which removes moisture and, if you hold the vacuum, also checks for gross leaks. You don't mention if you did that. You also need to add oil to the system if you change the compressor. Some compressors arrive filled with oil. Do you have the proper amount of oil in the system? You also should have changed the orifice tube when changing the compressor. Did you change the orifice? This is more to remove debris since often compressors are changed due to rings disintegrating, since yours was just leaking it may not be as critical, but a good measure nonetheless.

Have you connected a manifold gauge set to the low and high pressure sides and monitored the pressures while using the A/C to see if the needles indicate an issue (charge level, restriction, etc.)? You're probably aware that an overcharged system can also cause the compressor clutch to cycle faster than normal as well.

I don't have the factory service manual for the 2000 model year, but it should be similar to the 2002 model year which I do have the manual for. The capacity for the 2002 model year is 34 oz. along with a system capacity of 6.6 oz of PAG oil.

As for checking the operation of the clutch, the following information may be helpful:
Clutch cut-out/open 2,999-3,275 kPa (435-475 psi)
Clutch cut-in/close 1,517-1,931 kPa (220-280 psi)
Low Charge Switch

• Open 69 kPa (10 psi)
• Close 138 kPa (20 psi)

Good luck!

-Rod