This DIY will guide you to recharge your A/C system properly.
Approximate cost: $30
Approximate time: 2-4 hours
Tools needed: A/C manifold gauge and vacuum pump. Both can be borrowed for free from any local auto parts store. You put a deposit down and they refund your money when you return it.
Manifold gauge:
Pump:
Note: When you borrow the pump, make sure they give you a bottle of the appropriate oil to fill it properly. They will refund you the money for the oil when you return everything.
Note: When you borrow the AC manifold gauge, try to get the newest one they have and inspect all the green o rings on the attachments. They're commonly either missing or worn out which leads to system leaks.
The system is filled by weight, and not by pressure. It calls for 25-27 oz of R134a. You will need Two 12oz cans of R134a (without additives such as oil or stop leak) and one 3 oz can of oil recharge (usually contains 1oz of r134a and 1 oz of PAG oil and 1oz of additives). Make sure the 3 oz can of oil recharge you get contains PAG 46 oil. PAG 100 or 150 is NOT compatible with e46 system. An alternative method is to use another 12 oz of r134a instead of the 3oz bottle of oil additive. You will weight this last bottle on a scale and add the appropriate amount. I did not have a scale and to me that is just one more variable to worry about.
You will also need 1 can tap tool. It MUST be compatible with self sealing cans (all r134a cans are now self sealing cans). Do not buy the old piercing type for the old cans.
Advance auto:
R134: https://shop.advanceautoparts.com/p/...earchTerm=r134
Oil Recharge: https://shop.advanceautoparts.com/p/...archTerm=r134a
Can Tap: https://shop.advanceautoparts.com/p/...4a%20can%20tap
Walmart:
R134a: https://www.walmart.com/ip/Super-Tec...12-Oz/10316793
Oil recharge: https://www.walmart.com/ip/Super-Tec...3-Oz/337218764
Note, I recommend you buy an extra 1 or 2 of the 12oz bottles. Chances are you will make a mistake somewhere and would need a fresh bottle on hand.
Before we start:
1. I am not responsible in any way if you damage your car following my instructions.
2. It is ILLEGAL to vent r134a to the atmosphere. It is damaging to the ozone layer.
3. Do NOT breath r134a or let it contact your skin or eyes. You should wear gloves and glasses.
Step 1:
Take your car to an a/c shop and have them vacuum out your old r134a to be recycled appropriately. If your system is already empty due to leaks or damaged AC condenser, you can skip this step.
Step 2: Connect the manifold gauge hoses and couplings. Red is high pressure, blue is low pressure and yellow is for vacuum pump as well as recharging. The high pressure hose usually attaches on the right, low pressure on the left and vacuum/refill hose in the middle.I will refer to these as high/low/middle hose from now on to make it easier to follow.
Step 3: Fill up your vacuum pump with appropriate oil to the required level and plug it in. Attach the middle/yellow hose to the appropriate fitting on the vacuum pump. The vacuum pump usually has two fittings, screw the cap onto the one you wont be using.
Step 4: Hang your manifold from your hood. Turn the high and low pressure valves to closed position at the manifold. Turn the high and low pressure couplings that attached to your service ports to closed position (make note of clockwise vs counterclockwise rotation to open/close).
Step 5: Attach your low pressure coupling to the low pressure service port on the passenger side near the firewall.
Step 6: Attach your high pressure coupling to the high pressure service port next to passenger headlight.
Step 7: MAKE SURE you performed step 5 and 6 correctly. Its a common mistake to think that you attached them right but they're actually loose.
Step 8: Turn both high/low manifold valves to open position.
Step 9: Turn both high/low couplings at the service port to open position.
Step 10: At this time, your car's AC hoses are open to the manifold hoses. But the system contains atmospheric air and moisture which must be vacuumed out. Moisture is bad for the system and this is a crucial step.
Step 11: Turn on the vacuum pump and let it run for 10 minutes, You will notice that the gauge on the left (low pressure gauge) will read approximately -30. It doesn't have to get to -30, but as long as you're close its good enough and means the pump pulled a vacuum.
Step 12: After 10 minutes, turn BOTH valves at the manifold gauge to CLOSED position. Leave the couplings at the service port in the OPEN position. The system is now closed to the vacuum pump but the manifold gauges are still open to your cars AC hoses and it is able to measure the pressure. Observe the low pressure gauge, it should remain exactly where it was before you turned the vacuum pump off. (at around -30). wait 5 minutes to make sure the gauge doesnt go back to zero. If it does then you have a leak in the system somewhere and the atmospheric air is making its way into your system somehow. You can diagnose where a leak is by filling the system with UV dye and wearing appropriate glasses/using appropriate light to find out where the leak is. That's beyond the scope of this DIY.
Step 13: After 5 minutes, if your gauge needle did not move, then you know you don't have any leaks. Turn the valves at the manifold back to OPEN position and turn on the pump for 45 minutes to completely remove all outside air and moisture from your lines.
Step 14: After 45 minutes, turn the valves at the manifold gauge to CLOSED position. Leave the couplings at the service port in OPEN position. This closes the manifold gauge to the yellow/middle line.
Step 15: Disconnect the yellow/middle hose from the vacuum pump, but leave the other end attached to the manifold gauge. Outside air can't make its way into the system now because we closed the valves on the manifold in the previous step.
Step 16: Attached your can tap fitting to the yellow hose. MAKE SURE YOUR CAN TAP VALVE IS TWISTED TO CLOSED POSITION.
Step 17: Attach your.12 oz can to the other end of the yellow/middle hose.
Step 18: Turn the can tap valve to open position. You will hear a temporary flow in the yellow/middle hose.
Step 17: We are now ready to fill, except your yellow/middle hose contains atmospheric air which we need to purge first. There is a valve at the manifold gauge above where the yellow/middle hose attaches. Press this valve with a screw driver and let the air in the hose out. This should take 1-2 seconds. Do NOT let too much r134a to escape this valve as you will throw off your calculations. We don't want to lose too much R134a
Step 18: Turn on the car, turn on the ac, put temperature on the lowest possible. Fan speed should be on low. All windows down and doors open so that cold air is lost to the outside (we want the AC compressor to work hard and turn on a lot).
Step 19: At the manifold gauge, turn the low pressure valve to OPEN position. The High pressure valve at the manfiold should be in CLOSED position and remain CLOSED from here on. We only fill through the low pressure hose. BOTH your couplings at the service ports are in OPEN position.
Step 20: R134a is now flowing through the low pressure hose into your system. As the compressor turns on, it will suck it out of the canister. You can observe this as the gauge readings will begin to fluctuate. Do not leave your can somewhere hot or in the sun. Leave your can right side up and turn it 90 degrees every 15 seconds for the gas to flow better. There are two ways to know if the gas is actually flowing: 1. the can will begin to feel super cold. 2. the manifold gauge has a tiny glass window which will show bubbles/liquid flowing.Once you have enough in there, the AC will begin to feel cold.
Step 21: When the can begins to get low, it doesn't flow as good, turn it upside down or sideways. a 12oz bottle may take 15 minutes to empty.
Step 22: When the can is empty, turn the low pressure valve at the manifold gauge to CLOSED position to close the system off to the middle/yellow hose.
Step 23: Twist your valve can tap to closed position so that outside air doesn't make its way into the middle hose when you swap cans.
Step 24: Take old can off and put new can on and turn can tap valve to on position. You may purge at the purge valve again if you wish but it should not be necessary unless somehow you got outside air into the middle hose.
Step 25: Turn the low pressure valve back on at the manifold for gas to flow into the system again.
Step 26: When the second can is empty, close the low pressure valve at the manifold to prepare for a new can. Follow the same steps as above.
Step 26: Follow the same steps as above to connect the 3 oz can.
Step 27: Add the 3 oz can to the system until empty.
Step 28: We started with a total of 27 oz, but we have lost a little R134a here and there as we purged the lines etc, so we should be left with somewhere between 25-27 oz added to the system. The system called for 25-27 oz so we should be good. Your AC should be blowing ice cold now.
Step 28: Closed all FOUR valves.
Step 29: Remove couplings from your service ports. MAKE SURE YOU CLOSED THE COUPLINGS BEFORE YOU REMOVE THEM OR YOU WILL PURGE R134A FROM YOUR SYSTEM TO THE OUTSIDE.
We are done.
Approximate cost: $30
Approximate time: 2-4 hours
Tools needed: A/C manifold gauge and vacuum pump. Both can be borrowed for free from any local auto parts store. You put a deposit down and they refund your money when you return it.
Manifold gauge:
Pump:
Note: When you borrow the pump, make sure they give you a bottle of the appropriate oil to fill it properly. They will refund you the money for the oil when you return everything.
Note: When you borrow the AC manifold gauge, try to get the newest one they have and inspect all the green o rings on the attachments. They're commonly either missing or worn out which leads to system leaks.
The system is filled by weight, and not by pressure. It calls for 25-27 oz of R134a. You will need Two 12oz cans of R134a (without additives such as oil or stop leak) and one 3 oz can of oil recharge (usually contains 1oz of r134a and 1 oz of PAG oil and 1oz of additives). Make sure the 3 oz can of oil recharge you get contains PAG 46 oil. PAG 100 or 150 is NOT compatible with e46 system. An alternative method is to use another 12 oz of r134a instead of the 3oz bottle of oil additive. You will weight this last bottle on a scale and add the appropriate amount. I did not have a scale and to me that is just one more variable to worry about.
You will also need 1 can tap tool. It MUST be compatible with self sealing cans (all r134a cans are now self sealing cans). Do not buy the old piercing type for the old cans.
Advance auto:
R134: https://shop.advanceautoparts.com/p/...earchTerm=r134
Oil Recharge: https://shop.advanceautoparts.com/p/...archTerm=r134a
Can Tap: https://shop.advanceautoparts.com/p/...4a%20can%20tap
Walmart:
R134a: https://www.walmart.com/ip/Super-Tec...12-Oz/10316793
Oil recharge: https://www.walmart.com/ip/Super-Tec...3-Oz/337218764
Note, I recommend you buy an extra 1 or 2 of the 12oz bottles. Chances are you will make a mistake somewhere and would need a fresh bottle on hand.
Before we start:
1. I am not responsible in any way if you damage your car following my instructions.
2. It is ILLEGAL to vent r134a to the atmosphere. It is damaging to the ozone layer.
3. Do NOT breath r134a or let it contact your skin or eyes. You should wear gloves and glasses.
Step 1:
Take your car to an a/c shop and have them vacuum out your old r134a to be recycled appropriately. If your system is already empty due to leaks or damaged AC condenser, you can skip this step.
Step 2: Connect the manifold gauge hoses and couplings. Red is high pressure, blue is low pressure and yellow is for vacuum pump as well as recharging. The high pressure hose usually attaches on the right, low pressure on the left and vacuum/refill hose in the middle.I will refer to these as high/low/middle hose from now on to make it easier to follow.
Step 3: Fill up your vacuum pump with appropriate oil to the required level and plug it in. Attach the middle/yellow hose to the appropriate fitting on the vacuum pump. The vacuum pump usually has two fittings, screw the cap onto the one you wont be using.
Step 4: Hang your manifold from your hood. Turn the high and low pressure valves to closed position at the manifold. Turn the high and low pressure couplings that attached to your service ports to closed position (make note of clockwise vs counterclockwise rotation to open/close).
Step 5: Attach your low pressure coupling to the low pressure service port on the passenger side near the firewall.
Step 6: Attach your high pressure coupling to the high pressure service port next to passenger headlight.
Step 7: MAKE SURE you performed step 5 and 6 correctly. Its a common mistake to think that you attached them right but they're actually loose.
Step 8: Turn both high/low manifold valves to open position.
Step 9: Turn both high/low couplings at the service port to open position.
Step 10: At this time, your car's AC hoses are open to the manifold hoses. But the system contains atmospheric air and moisture which must be vacuumed out. Moisture is bad for the system and this is a crucial step.
Step 11: Turn on the vacuum pump and let it run for 10 minutes, You will notice that the gauge on the left (low pressure gauge) will read approximately -30. It doesn't have to get to -30, but as long as you're close its good enough and means the pump pulled a vacuum.
Step 12: After 10 minutes, turn BOTH valves at the manifold gauge to CLOSED position. Leave the couplings at the service port in the OPEN position. The system is now closed to the vacuum pump but the manifold gauges are still open to your cars AC hoses and it is able to measure the pressure. Observe the low pressure gauge, it should remain exactly where it was before you turned the vacuum pump off. (at around -30). wait 5 minutes to make sure the gauge doesnt go back to zero. If it does then you have a leak in the system somewhere and the atmospheric air is making its way into your system somehow. You can diagnose where a leak is by filling the system with UV dye and wearing appropriate glasses/using appropriate light to find out where the leak is. That's beyond the scope of this DIY.
Step 13: After 5 minutes, if your gauge needle did not move, then you know you don't have any leaks. Turn the valves at the manifold back to OPEN position and turn on the pump for 45 minutes to completely remove all outside air and moisture from your lines.
Step 14: After 45 minutes, turn the valves at the manifold gauge to CLOSED position. Leave the couplings at the service port in OPEN position. This closes the manifold gauge to the yellow/middle line.
Step 15: Disconnect the yellow/middle hose from the vacuum pump, but leave the other end attached to the manifold gauge. Outside air can't make its way into the system now because we closed the valves on the manifold in the previous step.
Step 16: Attached your can tap fitting to the yellow hose. MAKE SURE YOUR CAN TAP VALVE IS TWISTED TO CLOSED POSITION.
Step 17: Attach your.12 oz can to the other end of the yellow/middle hose.
Step 18: Turn the can tap valve to open position. You will hear a temporary flow in the yellow/middle hose.
Step 17: We are now ready to fill, except your yellow/middle hose contains atmospheric air which we need to purge first. There is a valve at the manifold gauge above where the yellow/middle hose attaches. Press this valve with a screw driver and let the air in the hose out. This should take 1-2 seconds. Do NOT let too much r134a to escape this valve as you will throw off your calculations. We don't want to lose too much R134a
Step 18: Turn on the car, turn on the ac, put temperature on the lowest possible. Fan speed should be on low. All windows down and doors open so that cold air is lost to the outside (we want the AC compressor to work hard and turn on a lot).
Step 19: At the manifold gauge, turn the low pressure valve to OPEN position. The High pressure valve at the manfiold should be in CLOSED position and remain CLOSED from here on. We only fill through the low pressure hose. BOTH your couplings at the service ports are in OPEN position.
Step 20: R134a is now flowing through the low pressure hose into your system. As the compressor turns on, it will suck it out of the canister. You can observe this as the gauge readings will begin to fluctuate. Do not leave your can somewhere hot or in the sun. Leave your can right side up and turn it 90 degrees every 15 seconds for the gas to flow better. There are two ways to know if the gas is actually flowing: 1. the can will begin to feel super cold. 2. the manifold gauge has a tiny glass window which will show bubbles/liquid flowing.Once you have enough in there, the AC will begin to feel cold.
Step 21: When the can begins to get low, it doesn't flow as good, turn it upside down or sideways. a 12oz bottle may take 15 minutes to empty.
Step 22: When the can is empty, turn the low pressure valve at the manifold gauge to CLOSED position to close the system off to the middle/yellow hose.
Step 23: Twist your valve can tap to closed position so that outside air doesn't make its way into the middle hose when you swap cans.
Step 24: Take old can off and put new can on and turn can tap valve to on position. You may purge at the purge valve again if you wish but it should not be necessary unless somehow you got outside air into the middle hose.
Step 25: Turn the low pressure valve back on at the manifold for gas to flow into the system again.
Step 26: When the second can is empty, close the low pressure valve at the manifold to prepare for a new can. Follow the same steps as above.
Step 26: Follow the same steps as above to connect the 3 oz can.
Step 27: Add the 3 oz can to the system until empty.
Step 28: We started with a total of 27 oz, but we have lost a little R134a here and there as we purged the lines etc, so we should be left with somewhere between 25-27 oz added to the system. The system called for 25-27 oz so we should be good. Your AC should be blowing ice cold now.
Step 28: Closed all FOUR valves.
Step 29: Remove couplings from your service ports. MAKE SURE YOU CLOSED THE COUPLINGS BEFORE YOU REMOVE THEM OR YOU WILL PURGE R134A FROM YOUR SYSTEM TO THE OUTSIDE.
We are done.
Attached Files
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