yuviscorp

How To Recharge Ac System?

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Hey PPl, I have 2000 Mazda 626 2.5l V6 engine LX. I am running low on Freon, it was good AC was working good few days back, Now it just blows hot air.

I get it tested from local mechanic, he said a minor leak, which he can put a dye and and recharge the system. but he is asking $250 for this stuff. I have seen many ac freon/sealer bottles in walmart/autozone available in 20-30$ with gauges. I am thinking of doing it myself. Dont want to spend too much money on this. But i am worried more than confused. I can see too ports 1 is covered with blue cap and other covered with black cap? how to identify which one is low pressure port?

I have seen may videos on youtube. but havent yet got much confidence about it.

Please help me guys.These days temp is so high and my ac is not working.

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The one you will be filling in should be up near the passenger side tire. I dont remember what color the cap was... Its easy to do. you have to have your car running, and your A/C on. You can get one of the cans with sealant. But you have to make sure that you fill with the same kind of stuff next time. Because different types dont mix. There are synthetic ones and something else.. Sorry, Did mine a WHILE ago.. Need to redo it. I got one of the large 20Oz Cans at walmart with the gauge for like 20$. If you need pictures, I could take some. Lemme know how it works. -DaneC

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Hey Bro, Thanks for d information, Actually I did it and AC is working fine.

Thanks for your answer, It seems mostly I followed all steps you mentioned

I just wanna ask, I kept pressure bet 35-40 means the filled range, but the temp in that range was 24 degrees, Is it OK?

seems car cools now easily, But not as much colder, when it was cooling before.

I used Artic refrigerant, bought a 22 oz bottle and extra 8 Oz of the same brand , and normal sealant(red dye) from walmart.

guide me on pressure range.

and one more thing, my rear speakers are off now, what are the specs for rear speakers? Please let me know.

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The temp in that range should be fine. I used arctic refrigerated as well. If you look underneath your hood, there should be a sticker on the left hand side that should tell you what pressure range to use for the A/C system. I think the max you want to go is somewhere around 50-55psi. But I could be wrong, so you want to check. after you fill it and run the a/c system, you will most likely notice that the pressure will drop from what pressure you put in there, so you will have to add more refrigerant.

As for the car cooling more easily, your car will take some time to get the new refrigerant through the system. it may take a couple starts of the A/C system to get it iced.

As for the specs on the Rear speakers? I'm not entirely sure on that. Might have to search the forum for speaker specs. lol. img-302677-1-tongue.gif

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Id be careful using sealant, when i took my ac class at school, my teacher was telling us that allot of shops wont work on the ac system if it has sealant in it. Atleast they wont do anything where they have to recover the freon.

And on the couple starts thing, if you hold the can upside i think when you're putting the freon in it will freeze, if you hold it right side up it should cool almost right away. (Im pretty sure this is what my teacher told us)

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Not sure about the upside down/right side up deal. But I do know that you are supposed to shake the can while loading the freon in there.

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1995 Mazda 626 2.0L AC Recharge/Refill.

Directions are on the can you can pick up from most auto parts stores. You can periodically and lightly shake the can. Recommend getting the $30 kit that includes the pressure gauge. Took less than 5 minutes to do a partial recharge on 3 cars that needed recharging (still half the can left over). Lowest was 40 PSI. Recommend 50-55 PSI on my 1995 A-Spec 626.

Refrigerant required and correct PSI for your car is usually on the underside of the hood on the left most sticker so make sure you check that before doing anything as it might change depending on applicable state and country laws.

Run the car for a couple minutes with A/C on high, plug it in, check the pressure, then charge to 50-55 PSI. It's kind of like filling your tires with air. You have to fill then check, fill then check. Unlike filling your tires with air you don't have to take the hose off the port. You only have to wait a bit between charges for the pressure gauge to register the correct PSI again.

If the gauge is reading above redline while it's connected it's probably because you aren't running your car with full A/C on. That's definitely a requirement to get correct PSI readings.

Here's a pic of my brother recharging mine. He did a great job. You can see the low side maintenance port. It has a blue cap near the passenger front tire.

img-314655-1-P3300087.jpg

Some recharge cans come with a push button on top (like the one pictured) and others come with a trigger.

Unlike the air in your tires you really want to avoid having to bleed off excess refrigerant by adding too much pressure, so go slow. As long as you don't get distracted and fill to 70+ you'll be fine. The more pressure you put into the lines the more likely you could burst a hose/pipe so don't get over zealous with it. Anywhere between 50 to 55 PSI is perfect.

img-314655-2-P3300088.jpg

Can highly recommend the DIY recharge kits w/pressure gauge.

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I'd like to add my 2.4 cents here.

As I have stated before, I do not like the hose-on-a-can things. They do not show you the whole picture.

That said, it is usually cheaper to buy a can of that and take a leap of faith, than to take the vehicle to a shop where a trained and certified technician can properly diagnose and remedy any problems leading to the symptom (not cooling). You can also add can after can of refrigerant, where we are required by the EPA to fix substantial leaks found. (I am well aware that most shops today won't even open the hood of your car without charging you $100. I'm not a fan of that either, but it is what it is.)

Perhaps just as important, especially if you plan to keep the car for long, a more expensive problem that can occur if you just keep adding refrigerant to a leaky system is that as the refrigerant leaks out, so does some oil. The compressor needs oil in it, just as your engine needs oil circulating through it. If your leak is bad enough for enough oil to leak out, the compressor will seize up, and spread contaminants through the rest of the system, requiring complete flushing (which on some cars is a real PITA because the dash will have to be taken out to get around the expansion valve). You can buy "oil charges" where a small amount of oil is forced into the partially charged system. Again, it's a bandage, but probably better than not adding any oil. You do have to be careful not to add so much oil that it diminishes the refrigerant capacity of the system so much that it no longer cools. You can find out how much oil is required to be in the system and avoid going over that much "added", but you'll never know for sure how much already remains in the system.

Be aware that if your system has leaked all of the refrigerant out so that there is no residual pressure remaining, the system should be completely evacuated and recharged. At this point, you may as well have the leaks fixed so that you aren't going through this again soon. By not evacuating the system completely (pulling a vacuum), you risk having moisture in the system. That moisture leads to an acidic mix in the system which will corrode the lines, compressor, and other components from the inside, again leading to even more expensive repairs.

If you decide to go ahead and get the hose/can combo, I would suggest placing a good fan in front of the condenser, and a meat thermometer in the center vent. Monitor the vent temperature and if it starts going up, you are most likely starting to over charge the system. Please note that it can take a few minutes for everything to stabilize after adding refrigerant, so go slow. Though it does not apply to cars with fixed orifice systems, expansion valve systems can be trickier to charge using the single hose method, as the expansion valve is an active component trying to keep the "right" amount of flow through the system. In doing its job, it causes the pressures to change to maintain that flow. (It's actually monitoring super-heat, but flow is easier to understand by most.)

The best way to charge an a/c system is by measuring the amount of refrigerant. That, of course, requires starting with an empty, evacuated system, which is beyond the ability of most DIYers. An accurate charge can also be made by measuring the sub-cooling or the super-heating of the refrigerant at a couple of places in a system, but that is beyond the ability and equipment of most DIYers.

I am not a fan of the "It worked for me, so it must be right." mentality. But, again, it is often the cheaper way out, and will probably get things working over half the time.

Sorry I can't be more enthusiastic about the DIY A/C maintenance. I have just seen too many systems brought to me for repair where the owner says, "I added a couple of cans and it still doesn't work!" Better to fix it right, than to cut corners here. Cutting corners can lead to pretty expensive repair bills. As a good example, a friend just brought a car over a couple of weeks ago. Even at a discounted labor rate, it cost her over $500 for me to replace the compressor, accumulator and orifice tube.

Dave

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Refridgerant does need to be recharged over time. It's not just because of a leak. I only needed to put in about 10 PSI into my system to recharge it. Used about 3/4 of a can recharging 3 vehicles. Took me 15 minutes.

If your car is well below what you would expect then perhaps a leak is present and it's best to take Dave's advice and have a shop look at it. Recharging is for minor adjustments only. If you have close to no refridgerant in your system think twice about wasting a can. They are between $15-$30. That's a lot of money to throw away on a leak.

EDIT:

I can confirm that applerule's image is correct. The low pressure fitting is a black cap on the accumulator near the passenger strut mount. Usually the cap is blue but for whatever reason it's black on the 5th gens.

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Sorry, but I have to disagree! If the refrigerant does not leak out, where does it go?

Your refrigerator or home A/C seldom, if ever need to be recharged because they are a sealed system that uses hard lines and soldered fittings for connections. The compressor is hermetically sealed, so there is no shaft seal to worry about. And there are no extreme thermal stresses to deal with either.

That type of system would not work in your car due to vibration and would be impractical because of maintenance. In your car, all of these things must be considered, so hoses are used, which over time become degraded and permeable. Shaft seals lose their ability to seal effectively. Fittings all have O-rings, which become deformed. Evaps and condensors erode from the inside from refrigerant that has become contaminated with moisture. In other words, the system leaks. The leaks may be miniscule and the refrigerant may take years to leak out enough for it to become a concern, but the system leaks, nonetheless.

Dave

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I'm certainly not going to disagree with Dave. He's what I would consider an expert and he would be happy to take me to school. I'd listen to gold_1999_626. :)

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So... I think I overcharged it or I have a wiring problem, or both.

I have a 2000 2.0L 626 automatic, but the guy that owned it before did some crazy stuff to the engine and I have already had to fix two wiring problems, I'm hoping this is just another wire problem.....

I charged it like you guys were saying and how the instructions stated, however now every 5 seconds (with the engine running, a/c and vent on high, charger hooked up but only for pressure gauging) it makes a sound similar to the sound a car makes when it's trying to get the engine started. Does that make sense? Here's what I have noticed:

- The pressure builds up over 5-7 seconds to 50psi (10 over what it says it should be on the can), does this noise for about 3 seconds while it drops below 30psi and then stops and starts all over again.

- If you are facing the engine, the fan on the right now spins (it wasn't before) but the fan on the left still doesn't spin.

- The two belts are spinning fine

- The noise sounds like it is coming from between the alternator and center of the engine

- It still doesn't blow cold air

I observed this for about 15 minutes trying to see if I could narrow it down. The fan not spinning makes me think it may be a wiring problem, but I don't know. Any help?

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That's probably going to be your A/C condenser or clutch. A recharge is only a band-aid. If your car doesn't respond positively to a recharge then it's time to seek the service of a professional A/C technician.

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Forgive my noob reply... would an automatic have a clutch? Is it internal?

Is the A/C condenser easy to replace? I am mild-moderately experienced with repairs (starters, wiring, suspension, brakes, etc.)

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It does have a clutch of sorts. It's an automatic clutch system which uses hydraulic fluid pressure instead. It's nothing like the way a manual car does it. It's more complicated so that shifting is much smoother.

For the A/C condenser I would say no. Take it to a specialist A/C garage unless you have professional tools such as a vacuum evacuator pump.

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I did some a/c work on my dad's s10 several months ago. He had a leak causing the refrigerant to leak out in 2-3 weeks. He took it to a shop and they recommended new compressor and condenser along with the inline filter.

He asked if I could fix it and I told him I could only replace the parts because of the vacuum required to refill the system. The job was simple and done in less than an 2 hours saving my dad a couple hundred dollars in labor. He had the shop recharge it a couple days later and it's still working.

That being said, if you need a cheaper but more effective fix than the can/guage combo, you should be perfectly fine changing the parts on your own. Just don't try the diy can after changing parts.

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If you have a compressor, you can buy a vacuum for the A/C for < $20 at Harbor Freight. It uses the venturi effect to suck the system down.

However, I have never vacuumed out a system that had leaked out, and have never had a problem....only replaced a receiver/dryer once, and that's because on that particular car, that was the part that was leaking. The fact is your system would have to be wide open to the air for a significant period of time for any moisture to realistically accumulate, not some pinhole in an o-ring somewhere that only leaks when there's a 20 PSI differential (meaning, you wouldn't get significant air intrusion even if left that way for a year).

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Get a food thermometer and stick it in the air duct.  The autoparts store gauges are worthless.  Charge it on a warm sunny day, and put the A/C on recirculate and add/subtract refrigerant until the air coming out the air vents in the car is about 38 F.  (thats the lowest I've been able to get mine anyway).  I took mine to a shop one time and they got it to 40 F.  I took it home and took a little bit out and got it down to 38 F.

 

I still have a leak though.  I just cant seem to get the condensor fittings to seal.  I put new o-rings on them and they are still leaking.  What junk.

 

Also, I'm fixing on buying a full A/C gauge set from Harbor Freight.  Does anyone know what the Low Side and High Side Pressures are supposed to be exactly?

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So I bought the gauges and the 2.5 cfm vacuum pump (self-powered) and a little oz scale from walmart.  So now I can do it all myself and put the exact amount of refrigerant into the system.

 

However, I'm still having problems.

 

I pulled a vacuum down to -29 inHG in about 20 minutes, and then put a 2oz can of ac oil in and filled it up to the exact amount of freon required by the sticker under the hood - 750 g (or 1 lb 10 ozs).

 

Nevertheless even on Max A/C (recirculate) sitting still in the driveway, fan on full blast, the temperature coming out of the vents is only about 55 F.  (80 F outside)

 

This is sad, because I threw a random amount of freon into my wifes Pontiac G6 and it can cool down to 47 F sitting still in the driveway (and thats not even with the perfect amount of refrigerant).

 

What am I doing wrong???

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For one, you need to check the system pressures.  The fill amounts are approximate, and will vary from car to car, especially if you have aftermarket parts (like a receiver/dryer, condenser, etc.).  If the pressures look good, make sure your condenser and evap coils are clean and free of debris.

 

Another thing worth checking is the blend door/valve on the blower.  If the gasket is missing or the door isn't sealing shut, it may be drawing a small amount of air from the heater core.  Unlike some cars, the heater core on this car always has coolant flowing through it.  This makes it simpler and less leak prone, but that means you have a hot radiator sitting behind your dash all the time.

 

Also, don't assume the a/c in car A will perform the same as car B.

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Condenser, accumulator, and orifice tube are brand new (and thus aftermarket).

 

I just went out and turned it on and hooked the gauges up.  At MAX A/C (recirculate) with blower on full blast and 82 F outside, the pressures fluctuated a bit when I turned it on but they eventually settled at the low side pressure reading 39 and the high side reading 210.  The vent was still blowing air at 58 F even after 5-10 minutes!!!

 

This makes no sense to me.  No leaks are visible with an ultraviolet light in the engine compartment.  I guess I need to take the dash apart and bust into the blowing system???

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The "orifice tube" which on these cars should be a TX valve. I assume it really is a TX valve and has just been misnamed. Did you make sure you bonded the sensor tube to the where the old one was ?

 

TX valves regulate the pressure between high and low side and this is done via the sensor tube. Some do it directly with a refrigerant connection to the suction side. Some indirectly with a gas filled capilliary tube which is then bonded to the suction line out of the evaporator core. The colder the capilliary tube or the lower the sensor line pressure the more the valve opens to reduce the difference between high and low side pressures when less cooling is needed.

 

I don't think this is your problem though as the pressures seem ok. Are both the condenser fans running when you took the measurements ?

What refrigerant did you use ? The gauge pressures vary between R12 & R134A. If you are using R134A then 210 is a little low for 82F ambient.

 

If you are worried about the air mix door causing the problem un clip the clamp that joins the duct between the cooler box and heater box and put the temp probe in there. You can measure the air temp before the mix door. It should be possible to access this without removing the dash, just the cover under the blower and maybe remove the glove box for better vision on what you're doing.

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