Properly recharging AC system

[Ingvar]

Hi Eric and everyone else.

I have 2008 Mazdaspeed that needs to have AC system recharged.
I had to replace compressor as clutch seized during trip 9 hrs away, shredded engine belt, and due to pulleys configuration, installing a non-ac belt was not an option. Vehicle was towed back home.
I had new comp installed last Saturday. It’s comp from ebay, by some outfit called Frigette. Claimed to be new and was direct match on all fitments and pullet to our OEM Matsushita comp.
Couple things I did NOT do:
– I forgot to jump clutch to check if it works;
– I didn’t replace o-rings on OEM lines to comp. Was told it’s a must.
But I DID ad 150ml of comp oil to it, hand spinning before install and after mounted and lines connected.

Anyhow, I tried quick and dirty – a large can of freon from parts store, with gauge and quick coupler. Of course, it didn’t suck almost any in at loss of about $43. Maybe not full loss, can is mostly full. I amy finish it.
But here’s situation. Normally what we did before, we’d jump pressure switch, to kick in comp so that comp sucks freon it.
This car either does not have one or I have no idea where to find it. I am NOT messing with ac relay, don’t want to blow something.
I have 2 assumptions: either there is air trapped inside the lines that prevents charge, or clutch is not engaging (yes, it’s ebay comp)hence I can not recharge it.
System is rated for 1.1kg of freon. $$ to keep tossing at it.
As of 2 days ago I do have vac pump and manifold gauge.
I am planning to tackling this Saturday morning, but want to be prepared.
I did watch your video, Eric, yet still have questions.
Question 1: will vacuum pump suck oil out of comp?
Question 2: when you started charging system, you opened only BLUE manifold valve for the freon to flow into the L line. OK, then how does H line gauge show pressure, if it’s closed? Or, it’s opened at the line coupling, but closed at the manifold? And then pressure gets as far as manometer only and shows it?
Question 3: how do I mate manifold freon charge line with cheapest freon cans available? White 134 cans? Yellow hose with T handle and piercing pin is supposed to have proper coupling, or I need to buy or rig something else? Sorry for being cheap, but this car was a money pit so far and is up for sale.

I shall jump clutch before doing all this, and will replace o-rings, I have lift and it’s easy access. System is empty anyway, so it’s 15 minute job.

Clarification is appreciated.

Topic

[Its me]

#1… Did you vacuum the system and check for leaks before you tried to add the refrigerant? If not, you need to start over by vacuuming the system (30 mins) and ensure it holds for 15-30 minutes (ensure there are no leaks)… If so, the leak has to be found and repaired…

#2… Did you replace the receiver/dryer or Accumulator (depending on what type of system it is), You should replace the dryer or accumulator anytime you replace a compressor… (most A/C compressors companies will not warranty a compressor without replacement/proof that a dryer/accumulator was purchased at the same time or installed..

#3… Condition of the condenser… You say it was just a clutch seizing… Chances are the compressor went bad internally and seized up and burned up the belt because the clutch was still engaged and the compressor was not moving internally…. If the compressor went bad internally, a new condenser should be installed (very few manufacturers recommend flushing condensers after this type of damage has occured)… Just better to get a new one… Also, ALL the lines in the system should be removed and manually flushed with a special tool and cleaner… When you do this, it is good to replace all the O-rings and ensure you lube them with your recommended oil…

If you do not clean out the system properly after catastrophic compressor damage, then small metal bits left over in the system will get into the new compressor… this translates to the new compressor working anywhere from a few days to a few months before it goes bad as well… A clean system is a happy system… It can be time consuming, but has to be done right…

#4… I don’t know if this system uses a TXV (Thermal expansion valve) or an orifice tube… If it has an orifice tube, then it should be replaced as well… If you have an accumulator, then you should have an orifice tube…

To answer questions….

Vacuum will not suck out oil…

You should only charge on the low side (blue) and when hooked to a manifold you shut the high side off at the manifold… (Yes you can charge the high side if you have pulled vacuum on the system and the car isn’t running, but I do not recommend that technique for beginners)…

The gauges will read pressures as long as they are hooked up and the valves (the blue and red ones that attach to the car’s lines) are open… The top valves on the manifold open to allow flow from the lines going into the manifold to the Yellow service line)….

When charging, you should monitor the high side pressure (ensure the valve is closed on the manifold, and open on the line attaching to the High side fitting)…. A rule of thumb is the High pressure should be 2.5 to 3 times the ambient air temperature…(in Fahrenheit)

The clutch will start running when proper pressure is in the system… It can take several minutes to suck the refrigerant into the system…

While charging, the engine should not be at idle… Manufacturers can differ, but the rpms should be anywhere from 1500 to 2000…

There is a can tap to screw into the refrigerant can (and pierces it) which has a fitting that attaches to the yellow service line… If you want to do through a manifold, then you need this piece…

An easy way for a DIYer to do it is to add the proper amount of refrigerant directly with one of those attachments with a pressure gauge and ambient air temperature dial that you buy for re-charging your system…

A/C should be charged by weight… Its good you know exactly how much refrigerant your system takes… Most cans come in 12 ounce versions… If your A/C takes 38 ounces, then you just add three whole cans and two ounces more…

Here is a link which shows exactly how much refrigerant and oil to add for others who may want to follow..

http://www.techchoiceparts.com/refrigerant-and-oil-capacities

-Karl

[Ingvar]

Thank you.
No, didn’t vacuum system. Will now. Now that I have all the tools.
No, I am not going to replace any more parts on this car. It’s lame, but it took so much of our money in such a short period of time, that I am tired of tossing $$ at her.
Only clutch went bad, long story. There should be no metal shards in dryer.

I got it about manifolds. Matter of fact, out of curiosity, I just stepped out and put gauges onto the system.

Surprise. Somehow, there is ton of pressure in it, that’s after comp was removed and system was open for over a week, while we were waiting for comp to come in.

With engine NOT WORKING, L side showed 60 and H side showed 32. Clutch never kicked in after comp re-install. Where the pressure is from I don’t know.

[Its me]

With the engine off, the pressure should equalize…. If there is pressure after you opened the system, you have blockage…

Good luck making it work…

-Karl

[Joe]

is there pressure in the gauge set by chance? If the system was open then there should be 0 pressure in the lines.

TBH you should replace the receiver/dryer like karl said. They’re like $30 and will save your $3-400 compressor you just bought. You also left the system open for a couple of days. I’m willing to bet there’s a ton of moisture buildup in the receiver/dryer.

In my experience the clutch usually goes bad because the bearings in the compressor were going bad. You should ALWAYS replace the receiver/dryer when you replace the compressor. you should also replace the orifice tube (like $2). Especially on fords where the o-rings tend to come apart and get caught up in the tube.

[Its me]

I will close out with this… A/C systems are not something that can be done half hearted or halfway… Either do them right the right way, or you are seriously, seriously just flushing your money away..

I know money can always be an issue, and frustration sets in… I really think you need more than just a compressor and believe that if you go the way you are planning, you will not have any Air conditioning and will have wasted money on refrigerant..

You may find condensers that are reasonably affordable (under $100) online and as stated, an Acumulator or dryer may be $30 or so….an orifice tube, maybe $5… If your system has been open for more than a few hours, the desiccant is probably shot…

Not trying to be D#@#hole, but just giving the facts based on experience….

Eric does not even suggest doing this (A/C repairs as DIY)…. (as I am sure he will add later)… I will give advice if asked, but it has to be followed to a T or else much time, effort and money is for naught… The fact that this system still has pressure after it has been opened and the compressor not cycled is a big red flag…

I wish you good luck, but really recommend you do this right or don’t bother wasting your time…

-Karl

[Tom]

Just want to back up what the others have said here. I am NOT a technician, nor am I trained in any way on AC service or repair, but I’ve done a ton of research on A/C systems in order to be able to properly service my own. Any time the system is open for any period of time, the receiver / dryer needs to be replaced, no questions about it. If the clutch “seized up” it would simply constantly turn the compressor. This in and of it’s self would not cause any damage to your belt. The belt doesn’t get damaged until the compressor then seizes up, and stops spinning, which in turn keeps the pulley from spinning, and that is what tears the belt apart.

I wouldn’t waste the money on a compressor if I didn’t intend to spend the money to replace the condenser and receiver dryer, and service the system right.

If you didn’t intend to spend that money, you could simply have bought a new clutch, or a junk yard compressor, bolted it in, and put the belt on it without hooking up the clutch, and it would essentially work like an idler pulley. You spent the money on a new compressor, why do things in such a way that they are pretty much guaranteed to ruin it?

[Ingvar]

Hi all.

I guess a bit of background will help. As this happens in every automotive forum to every new poster with a strange question.
No, I am no rookie to cars. Been working on my cars since 1990. My cars, pals, cars, just cars.
AC specific, I had recharged quite a few and did several compressor swaps. I did several clutches replacements. Every time successfully including DIY recharge.
This particular car went on a 9 hr trip one way, and about 45 minutes away from destination, started making grinding noise. Come to find, it was ac clutch. Driven by my son. Car, not clutch, of course.
Him and his buddy pulled clutch plate off to find bearing in basically pieces. Clutch bearing, not comp bearing. They found a matching bearing and replaced it. While doing this, and I have seen many Mazda 3 and Mazdaspeed owners do same, they warped the clutch plate. He took off home and Sunday, 2 hrs into drive, in Boise, he lost PS and muscled his car into Autozone parking lot. Lucky. Hired a mobil mech. Serpentine belt was ripped. Clutch plate was from what I can tell now, badly overheated. And it IS bent. Also, they found that idler bearing was in pieces too. Pulley configuration did not permit making car drivable with “no-ac” belt. Son rented U-Haul and towed car back to a total tune of close to $2000 for that trip.
This car in less than 2 yrs of ownership cost us close to $5000 in repairs. Much of it done by yours truly here. I AM TIRED of this vehicle. And I am NOT tossing any more money at it. It is up for sale, either with ac or “as is” and I don’t care if I were to lose some $$ on it.
FArthest I’ll go will be to get her back on the lift Saturday morning, jump clutch to make sure it works, if not – seller will pay me back, PayPal is good about this – will replace O-rings on comp, vacuum it completely, and try to recharge using manifold.
If it charges, it charges, if not, as is it is. I damn well KNOW what it will take to take her to ac shop. Will end up in a thousand or so bill, as they are minding their business, and will try to milk me for all kinds of replacements and repairs. And I have short fuse for this.
I have good guess why it has pressure on L side. As, likely, some freon stayed inside, then air got trapped, plus it took about half a large can of freon in, when I tried to recharge it “the simple way”.
But what really ticks me off is couple things:
1. fortunately, I DID DIY recharge systems before and successfully.
2. buddy across the fence is car flipper. He rebuilds cars and had dozens of them, with radiator and lines and everything disconnected or replaced after front end damage, recharged. 2 cans of freon, boom done. He never even vacuumed the systems. I started talking to him about vacuum, he looks at me like I am from space. And that is the guy who does this for living and for years.
So if you patiently read my rumble down to this line, let’s put it all on ice. Let me see what I can do, and I’ll post the final results. Yes, I am very well aware of all the cautions and hazards. I have not only done “research” but have hands on experience from multiple cars.
With that being said, I appreciate everyone’s input and suggestions. I do. Forums saved me lots of headaches, money and gave me a lot of education. This is where I go first thing with questions and I serve with my experience and advice in 6 of them. I simply never used manifold before and had some questions. Most of them answered, thank you.

All be well. Don’t get upset with me or think I’m a smart ars. I work on cars basically non stop, I feel, I am well entitled to some experience credit. But in this car case, there will be no another expensive “shop way”. She’s not worse it. It’s 2nd car in my life that really got on my nerve.

[Ingvar]

Sold the car yesterday. As is. Buyer was clearly informed ac is not engaging.
Where it all stopped, was this:
1. replaced stems in L and H ports, just for the heck of it.
2. vacuumed system, shut down pump and went shopping. Came back, it was still at negative 31 on L side and whatever it was before I left on the H.
3. jumped clutch, it engages fine
4. Recharged system. Took in 1.5 300 g cans of ref-t. System is rated to 500 g of it, or 1.1 lb. Pressure on L side went all the way to around 100. Supposed to be 110 according to shop manual. Never moved on H and clutch won’t engage.
Considering it was Saturday, shops closed, and apparently beyond me on electrical (I did not want to jump clutch to force system) I simply lowered the price and adjusted ad, mentioning ac does what it does.
Sold her next day.
For what it is, it appears to be some sort of electrical malfunction. Maybe pressure switch, maybe relay. Who knows. I am decent mechanic, I am only basic knowledge electrician. I had Expo LRV with similar problem, and they found it was simply overcharged. Bled some freon out and it all worked fine. I have gut feeling, should they take car to ac shop, and actually have system fully evacuated+flushed+recharged, it’ll work just fine.
That’s where the odyssey stopped.
Thank you all for putting up with my stubbornness.

[Its me]

Can’t say this outcome surprised me…

A few last things to memorialize this thread…

If your neighbor across the fence does not know that you have to vacuum a system (which is A/C 101) shows that he really does not have a clue about how to properly work on Air conditioning systems… Yes, you can probably get them to work, but the reason you vacuum a system is to remove air and moisture from the system… Moisture is the enemy of an A/C system… What you do is reduce the life of the system… If he flips them, he probably doesn’t care. An open system also attracts moisture to the desiccant in the dryer.. when it is saturated, the A/C will not blow as cold… Hence why you replace the dryer when you replace the compressor and/or open the system for any extended time… The Dryer should be opened and installed last…

Also, if you do not vacuum, the A/C system will not work efficiently as it could (while the air may blow cold) it may be 55 degrees Fahrenheit, whereas a properly running A/C system should be 38-42 degrees Fahrenheit. Perhaps in the Northern climates this will work well enough to get you through a summer… But it won’t work well in Miami Florida..

Do you not use inHg and PSI on manifolds where you are?

The reason I ask is your readings… 31 inHg is physically impossible to achieve on the Planet Earth… 30 inHg is known as a perfect vacuum (only achievable in space)… 29.92 inHg is the best that can ever be achieved on Earth (at sea level).

Also, Low pressure should never be above 55 PSI…Low pressure should be 25-55 PSI… You say the book says it should be 110? This leads me to wonder if your gauge set was bad…or as you said, there is a pressure switch issue.. or you are doing this with different gauge measurements…. Ironically, Eric’s newest video shows him and his frustrations at having a bad A/C manifold set…

I can get stubbornness, but do not comprehend it when people are trying to assist…I hoped you would have learned something from this thread, the fact that you state that you believe just a flush, evacuation and re-charge would make this system work leaves me uneasy… Assuming your gauges are correct, it shows that there is blockage somewhere in the system… Flushes on modern car condensers are practically worthless (although GM still has it in their procedures)…
Without a doubt, you need a new dryer, and I can say with reasonable certainty that it probably needs a new condenser and the lines need to be removed and cleaned properly (with new O-rings installed)… Then evacuate and properly charge… As I stated earlier, there is no halfway doing Air conditioning systems… Do them right the first time, or you will get them back again… Sometimes in worse shape… I have done my share of fixing DIYers mistakes with Air Conditioning systems…

-Karl

[EricTheCarGuy]

I’ll start by saying that I do not recommend AC work for the inexperienced or untrained. You can get in over your head really quick. That said, sounds like the problem has been solved with the sale of the vehicle. One thing I might have missed, when you have a compressor failure, it’s normally good practice to flush the system and replace the expansion valve or in the case of a GM, the orifice tube. These things can get clogged with debris from a failed compressor. To mirror what ToyotaKarl said, you can’t go about this in a half hearted way. You need to be mindful of what you’re doing and use your tools properly or you could be injured and also damage the environment, not to mention make the situation worse and more expensive in the long run. More info on HVAC here.

http://www.ericthecarguy.com/faq/solving-automotive-hvac-problems

[Author]

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