Correct refrigerant level of a automobile air conditioner

Sang · 14th May 2009, 15:09

Hi All,

Is there any way by which we can know the correct level of refrigerant(R134A) which should be present in car A/C for it to work well? Is this specific to car makes like seperate for Tata and Maruti cars or is it dependent on outside temp. I tried googling a lot to find it and found one link Refrigerant Temperature/Pressure Chart. I am not sure if this holds true for our Indian cars also, Any comments from experts are welcome.

sgiitk · 14th May 2009, 15:58

If you have a sight glass (some have and some do not) on the receiver dryer (often called gas bottle) which is a small cylinder (~50mm dia x 250mm) between the condenser and the evaporator then things are quite easy. With the AC running for a few minutes on full the sight glass should be clear. If you see the odd bubble it is Ok, howv\ever, if you see foam them you are short.

Another way is swirch on the AC and check the pressure on the suction line (any good mechanic should know the pressure). A third and crude way is to see the inlet (suction) line to the compressor. It should be cold with condensation.

HKS · 14th May 2009, 16:05

Quote:

Originally Posted by sgiitk

If you have a sight glass (some have and some do not) on the receiver dryer (often called gas bottle) which is a small cylinder (~50mm dia x 250mm) between the condenser and the evaporator then things are quite easy. With the AC running for a few minutes on full the sight glass should be clear. If you see the odd bubble it is Ok, howv\ever, if you see foam them you are short.

Another way is swirch on the AC and check the pressure on the suction line (any good mechanic should know the pressure). A third and crude way is to see the inlet (suction) line to the compressor. It should be cold with condensation.

In the 3 ways mentioned, first is the best DIY. In the 3rd method, the compressor pipe will cool even if there is less gas.

Sang · 14th May 2009, 16:14

Quote:

Originally Posted by HKS

In the 3 ways mentioned, first is the best DIY. In the 3rd method, the compressor pipe will cool even if there is less gas.

What I want to know is that if that AC gas filling guy is attaching some pressure montior then what should be its reading in absolute number. Last year when I got it filled from AC guy that person told me that gas in the AC was totally empty so has to fill it fully as a result He charged me for the complete cylinder instead of standard Rs. 400 for topup.

SirAlec · 14th May 2009, 22:35

It depends upon the Cubic capacity of compressor being used in your car.

Sang · 15th May 2009, 09:33

Thanks SirAlec for your reply! Now I want to ask it if there is anyplace where I can see cubic capacity of compressor present in my car and the correct corresponding gas presssure. Just a note - I have Indica and Baleno with me, so I am interested in knowing details for these two. Kindly let me know if somebody has ready reference to them for AC compressor details.

Thanks !

Jaggu · 15th May 2009, 10:26

I think this is where the refrigerant filling machine comes into place.

If you dont have the glass window to check gas level, machines are the best bet. And gas filling is measured by the pressure of the charge, only the lubricating oil needs other measurement. Nowadays the machines will take care of oil also, so goto a good ac mech with proper tools and you will get the right amount of recharge.

Next best check is AC grill temperature, it should come close 4-6 deg C, this can be measured using digital thermometers.

14th May 2009, 15:09	#1
Sang BHPian Join Date: Jun 2007 Location: Delhi Posts: 110 Thanked: 10 Times	Correct refrigerant level of a automobile air conditioner Hi All, Is there any way by which we can know the correct level of refrigerant(R134A) which should be present in car A/C for it to work well? Is this specific to car makes like seperate for Tata and Maruti cars or is it dependent on outside temp. I tried googling a lot to find it and found one link Refrigerant Temperature/Pressure Chart. I am not sure if this holds true for our Indian cars also, Any comments from experts are welcome.
	() Thanks

14th May 2009, 15:58	#2
sgiitk Senior - BHPian Join Date: Dec 2007 Location: Gurugram Posts: 7,971 Thanked: 4,809 Times	If you have a sight glass (some have and some do not) on the receiver dryer (often called gas bottle) which is a small cylinder (~50mm dia x 250mm) between the condenser and the evaporator then things are quite easy. With the AC running for a few minutes on full the sight glass should be clear. If you see the odd bubble it is Ok, howv\ever, if you see foam them you are short. Another way is swirch on the AC and check the pressure on the suction line (any good mechanic should know the pressure). A third and crude way is to see the inlet (suction) line to the compressor. It should be cold with condensation.
	() Thanks

14th May 2009, 22:35	#5
SirAlec Senior - BHPian Join Date: Sep 2006 Location: zxc Posts: 3,395 Thanked: 727 Times	It depends upon the Cubic capacity of compressor being used in your car.
	() Thanks

15th May 2009, 09:33	#6
Sang BHPian Join Date: Jun 2007 Location: Delhi Posts: 110 Thanked: 10 Times	Thanks SirAlec for your reply! Now I want to ask it if there is anyplace where I can see cubic capacity of compressor present in my car and the correct corresponding gas presssure. Just a note - I have Indica and Baleno with me, so I am interested in knowing details for these two. Kindly let me know if somebody has ready reference to them for AC compressor details. Thanks !
	() Thanks

15th May 2009, 10:26	#7
Jaggu Team-BHP Support Join Date: May 2004 Location: Bangalore Posts: 20,383 Thanked: 17,296 Times	I think this is where the refrigerant filling machine comes into place. If you dont have the glass window to check gas level, machines are the best bet. And gas filling is measured by the pressure of the charge, only the lubricating oil needs other measurement. Nowadays the machines will take care of oil also, so goto a good ac mech with proper tools and you will get the right amount of recharge. Next best check is AC grill temperature, it should come close 4-6 deg C, this can be measured using digital thermometers.
	() Thanks