I had problem with the 5.5mm bolts too. Stripped one out and had to actually drill holes into the old compressor to free the bracket. Went down to Lowes and found the M6 x 16mm allen head bolt. It worked perfectly and I replaced both of the new allen bolts in case I ever need to get them off again.

 

Question: When you drained the new compressor of oil. What port do I refill the compressor up with? Suction or discharge port? Does it matter?

 

Hey everyone, Noob question and situation here.
First of all, cnn, thank you for the awesome guide, I plan on using it to replace my compressor. But, before I do, let me tell you the symptoms, and maybe get some advice on if I'm going down the right track.
This is for our 2007 Odyssey, BTW. EX-L Trim.
About a few months ago (dead of winter), we started hearing whining coming from the engine upon start up. It would occur in the freezing cold. I know AC is used as part of the Defrost, and we certainly would power that up in the morning to help defrost the window. Anyway, the whining would go on for awhile, then cease. Well, that sound finally ceased.
As temperatures have risen, we finally hit a few days where the AC would have kept the cabin cool, but alas, nothing but lukewarm air coming out. That is with the AC fully on.

The troubleshooting began:
I have done AC work on my Subaru, and got a kit to check the pressure of the Low Pressure Port, and refill it, as I thought this might be the problem. When I hooked up the gauge, the pressure was over 300psi. When I turned on the AC in the van, it didn't drop at all. As I understand it, the pressure should equalize.
I then did something I didn't know I shouldn't do. Didn't realize 134a was bad stuff (thought it was CNC free, or whatever). I vented a ton of the stuff out of the low side port, bringing the pressure down to where the gauge said it should be. I now know this was totally the wrong thing to do, so sorry to the tree huggers out there. My bad.
After I had vented it down, I shut the engine down, let it rest, and then went to turn it back on. With the AC on the pressure was again in the 300+psi range. Strange stuff.
I have checked to make sure the clutch is engaging when the AC is on. It does. I can hear the relay click it, and see it spinning.
With the engine turned off, I have checked the clutch manually. It has been said that you should feel the resistance of a pump when turning it by hand. There is no resistance. I feel the resistance of the clutch itself (it doesn't spin like a flywheel or anything), but not the engaging of the pump.
I also have noticed that the cap for the low pressure side gets VERY hard to take off. I also noticed that there is a slight wheezing coming out of the low port. That is with the engine off. I'm thinking the slight leak in the low port is pressurizing the cap when it is on, and that is what makes it hard to take off.

So, with all of that said, it sounds like the compressor itself is bad. Would the low pressure port also be bad, or is that a symptom? I know the caps are designed to help "seal" the port, so is that normal behavior?

I just wanted verification that this is the case, and I can get the work done. My local Tunex shop will do recover for 20 bucks, and from what I've read and seen, I shouldn't have any problems doing the vacuum and recharge myself.

Thanks in advance for any advice and thoughts.

 

I have a 06 Odyssey EXL with 142k. The a/c compressor was not cycling on at all, I found that I had no power to the compressor, so I ordered and replaced the stator set, once I got the compressor running I check the pressures with my gauges, the low side was extremely high and the high side very low, which indicates that the compressor is bad. I have only had it for about 1 1/2 years. When I bought it from the individual he made a comment it me that the A/C had been worked on, what was done I do not know, I had just assumed it was serviced. I have not seen any leaks so I don't think the system has been exposed to the atmosphere any. After reading the info from this thread I have ordered Denso Compressor 471-1630 off amazon. My concern is with the high mileage, do I need to replace the Desiccant bag in the condenser, or any other parts? I live in AZ and there is not much moisture but with the failure of the compressor I am worried that I should flush the condenser & hoses, or if it's really that big of a deal?

 

Leaks can't always be seen so that's not really a valid test. What's the static system pressure on the gauges when the system is off?

With you not knowing then it would be a good idea flush the system. If you suspect the compressor is damaged then it's possible it has sent pieces into the condenser and the receiver dryer. This can turn into an expensive fix, unfortunately.

A couple of other things to check to possibly determine why the compressor failed would be the compressor relay. These like to stick closed and the compressor will stay on all the time, even with the key off. This can build very high pressures in the system when in use, along with draining the battery when they key is off.

Also, make sure the fans are running BOTH on low and high speed. It may be tricky to check high speed if the pressure in the system won't get to 221psi but it's important as without a fan running the system pressures will go very high at idle. The fan circuits are not simple either but it's important to make sure they're running properly both on low speed and high speed.

 

Quick question (my mechanic might be swindling me):

My A/C went out. I took my car to a mechanic to test for leaks, and he pointed out that the compressor was melted.

Now, the problem is that he said I need several parts -- receiver drier, expansion valve, and condensor -- along with the compressor, and only because he said that if the compressor goes bad then those parts are contaminated.

Is that mechanic telling the truth, or can I get away with just replacing the compressor?

 

Your mechanic knows his stuff. When the compressor suffers internal damage the pieces of the compressor will get lodged in the condenser. In older cars you could flush out the condenser but in newer cars, like our Ody's, the condenser coil tubes are so tiny inside that the flush will not remove the pieces and contaminants.

It only takes one very tiny piece of contaminant to get through the condenser and lodged in the expansion valve to make the expansion valve not work. The expansion valve is a very small orifice that keeps high pressure on one side and creates a low pressure on the other side. That's what causes the evaporator to remove heat from the air and blow cold air into the car. It's the pressure differential created by the expansion valve. It's a very tiny orifice inside the expansion valve.

The receiver/dryer is basically a desiccant bag for removing moisture (much like those found in the box with new electronics) from the system. That receiver dryer should be replaced when the system is opened and especially if there is any chance that there are contaminants in it.

So, if the compressor has a meltdown it is highly recommended to replace the receiver/dryer, condenser, and expansion valve. They'll probably flush the evaporator (the coil inside the car that gets cold) and then replace the rest of it. If this is not done then it only takes one small piece of contaminant to plug the system, cause the pressures to go extremely high, and ruin your new compressor.

So, no, your mechanic is not taking you for a ride. He is fixing your system the correct way so you don't come back with the same problem in a week.

 

Quick Question:

I've taken everything apart -- compressor and condenser/dryer are out of the car.

Should I get my hoses and system cleaned/vacuumed before attaching the new compressor and condenser/dryer? Or will a shop be able to clean out the contaminants in such a way that won't contaminate the new parts?

Mainly I'm wondering if I should attach my new parts first ... OR ... take the van to a shop with the parts disconnected.

Is there a way I can clean the hoses myself before re-attaching them?

There were contaminants through the system (thanks to the bad compressor), the hoses are good and I don't want to get new ones.

 

 

How to remove 2005 Honda Odyssey AC compressor:

I couldn't fit my compressor through the wheel well; instead, I disconnected the radiator hoses (just the two large hoses) and moved the radiator out of the way. I kept the oil lines attached, so all I did was move it out of the way; I didn't remove it from the car. Actually, my wife held it up while I unbolted the compressor. And since I had already remove the condenser, removing the radiator seemed like the logical next step.

I did have to drain the coolant (and will have to replace it afterwards), but the compressor was SO EASY to get to after that. I had almost a clear shot to ever bolt, and detaching the AC hoses and removing the compressor from the car was easy.

 

For the hoses, I've been looking into a solvent flush. However, I think the system would cost more than simply buying new hoses.

 

$17 at AutoZone, this is the best solution for cleaning hoses (instead of replacing them). But this is just for the hoses, not the complete system.

Now, keep in mind that I've already removed the compressor and condenser and the hoses that attach to those --

Here is my plan:
- Clean the hoses that I've detached with this fancy can of spray
- Follow that with compressed air to make sure hoses are clear
- Install my new compressor
- Install my new condenser (and dryer)
- Attach cleaned hoses to new components (new o-rings w/ a dab of PAG oil), but leave them detached to the rest of the system
- Take care down to a shop that will properly flush the rest of the system, attach my hoses, and install refrigerant.

 

The only things I would point out are that the receiver/dryer absorbs moisture so you don't want to leave the system open with the new dryer installed.

If you already have everything removed from the vehicle and are replacing the condenser,dryer, and the compressor, and then flushing the hoses, that only leaves the evaporator and expansion valve to be flushed and cleaned. Would it not be easier to flush and clean that before putting it back together? Then once the evaporator is clean, put it all back together, vacuum it down and then add a fresh charge. Make sure you properly charge the system with oil. You basically have a dry system with exception of whatever comes in the compressor.

 

Excellent point. I mean, why not? I figured it would be too difficult to flush the entire system; however, now that I look at it, I see that it's doable. Thanks for the encouragement.

I've since found this video that demonstrates it all --

 

Quick question: Does it matter which hole you pour the oil into?

 

I just drained and filled the oil in a 2002 Mustang GT AC compressor and it seemed to go in one port better than the other. Just pour it into whichever one will accept the amount you need to put in. I put some in each port.

 

Old thread resurrection. This DIY worked great on an 07 Pilot for me last week. Fubar'd clutch and stator, apparently due to leaking PAG oil from the shaft seal. I have a gage set anyways, so I only paid a shop for the evacuation. Old system still held 10 oz that they were able to recover.
One trick I used not discussed here was that instead of paying a shop to recharge, I used my manual MightyVac to pull decent vacuum after assembly (-25). I then left the system under vacuum all night both to check for leaks and make sure ANY condensed water that might have gotten into the system would be vaporized. Next evening I verified it was still under vacuum, pulled it down as far as my hand pump could take it, then hooked up to charge.
First you pierce the can to pressurize the gage set with all the connectors attached and valves closed.
Next, vent a little of the gage system on the can side to purge the 134a / air mixture and make it 100% 134a in there.
Before you open the valve to the low pressure side of the car system, use a precise kitchen scale to weigh the 134a can AFTER the air purge. This is your net start weight.
Now start the car and turn the AC on max. Compressor won't trigger right away if the line pressure sensor is working right.
Open the low pressure side valve on the gage manifold set and let the can empty into the system. If it's a cool day, a hair dryer will help the 134a in the can vaporize.
Once the can is empty (a good shake will tell you), record the empty weight and subtract it from your net start weight. The difference is how much you put in.
Repeat with following cans as necessary until you achieve the specified system 134a weight. (26.5 oz in the Pilot).
Pep Boys only charged me $33 to evac the system, but would have charge me another $60 to refill. 3@12oz cans at Walmart were $16.

 

Wow. I would NOT recommend you do it this way (the hand vacuum pump.) The thing to remember is that the vacuum does more than just allow you to put the refrigerant in. Pulling the vacuum down to 29" boils off any moisture in the system. If you don't pull it down that far you can be left with moisture in the system that will lead to premature failure. Since your system was open for a while during repair you have moisture in there from the air.

Everything else is good info. One tip, and it's what I do, is to get two refrigerant can taps. No matter how you do it (using the 12oz cans from Walmart) you will be left with a partial can. So, since the first can is the easiest to get into the system simply put a partial can in first. So, for example, if you need 26.5 oz in the system, just put in 2.5 oz from the first can. Then close it up and put on a new can with your other can tap. Then add the full second and third cans until they're empty. No more measuring required. Be sure to purge each time.

The last system I did was on a cool day. I was able to get the full charge into the system by using a bucket of hot water to put the can in. I didn't even have to start the engine and run the compressor. Since the system was cool and the refrigerant was warm it all went in.

Again, though, that initial vacuum down to 29" is really important. Running it that way for 30 mins or so boils all the moisture out of the system. Letting it sit for another 30 mins tells you whether the system has any leaks.

 

Yes, as John said 25 is not a good vacuum. At 25 inHg, the boiling temp of water is still over 130 deg F, meaning that you aren't evaporating the water. At 29 it is near room temp, and 29.9 inHg it is sub zero, so you can get more evap at that level.

 

The hand pump pulls the vacuum down to that point but doesn't continue venting the moisture that was in there so the moisture evaporated but stayed in the system. There's a high chance you'll have moisture-caused premature failure. If it was only $60 to have it filled I'd sure pay that. Around here it's $150 for a service.

All that said, you can rent (for free) an AC system vacuum pump from Autozone. I did it a few times before I finally bought my own from Harbor Freight.

 

Ah, Mr. Clark. We meet again. I'm still waiting for my "must replace" bolts in my timing belt job to bust too since I scorned replacing them. I appreciate meticulous, but I maintain that some folks overdo it.

It's true that water doesn't boil at -25. But I didn't submerge the stupid truck for crying out loud. The system was exposed to atmosphere for all of 2 hours during the job (the failure didn't vent the system) - and that was in an electrically heated garage. I didn't NEED to make any liquid water boil. 24 hours at -25 is plenty to allow mere evaporation to work fine. Any minute liquid water that was in there at the beginning was vaporized after that amount of time and the final pump job I did before recharge would address 90% of that. The dessicant pack (system never before opened) is plenty for the couple milligrams of moisture possibly left in the system. Not worth jacking up the cost of the job by 15% to improve on minutely. I'll fess up if it goes bad, but I highly doubt it.
Potentially good tip about the free tools at Autozone though. I forgot about that. My past experience with them has been that 80% of those loaner tools are worn out, but YMMV.

 

As you can tell, I obviously don't hold a grudge and my memory is good but short. Apparently the same can't be said for you. Thanks for calling me out...it's always appreciated. /Sarcasm.

As for the timing belt bolts that are recommended to be replaced, I didn't make it up. It's written in the service manual. I don't know that I ever said they would break if you didn't replace them, but whatever. They are relatively low torque so I don't think the issue is breakage but probably more whatever the thread locker is that they put on them. Admittedly, that's speculation since the service manual doesn't say why...it just says "replace." You can do as you like. I'm betting most people don't replace them.

Your "theory" on the moisture in the system, unfortunately for you, doesn't hold water (no pun intended.) If the system is sitting at -25" but is just closed off then where is the moisture going? It's evaporated but still in the system. It's just sitting in the system since you're not removing all of it. Most of the time the moisture in the system is all in the form of vapor to begin with but you can have condensed vapor in parts of the system that will not come out right away and will need to be "boiled" off. If it wasn't necessary to bring a system down to 29" or more, and let it run that way for 30 minutes, then nobody would do it as it takes a lot of time to do that.

I just didn't want anyone to follow your lead. It's a hack fix on your AC system and while you may get away with it, at least for a while, it's a good way to ruin an AC system.

 

Yes, a hack job description might be a bit strong. Yes, at least he got most of the air out. He might get lucky and it will last. In my opinion, the system is too costly for a shortcut like that. Having had to clean AC systems from destroyed compressors it's a job that is not very fun, especially for the DIY'er. Yes, it's worse to add that crap in a can but people should not think this is the right way to do an AC repair and expect it to last. As soon as you open it the system is exposed. Would I replace the receiver/dryer just for that quick exposure? Probably not. However, humidity in the air is usually around 50% or more in most places and warm air holds more moisture than cold air so the warmer it is, the more moisture there can be. I just wouldn't recommend anyone do it this way. You definitely want it pumped down to a strong vacuum, allowing any moisture to be pumped out, not just sitting in there under the vacuum. The only reason for letting a system sit under vacuum is to check for leaks. The sitting doesn't help with moisture removal.

 

It's been a rather long time since high school physics and gas law, but here's my answer.
If there is NO liquid water in the system, then once you reach a certain measurement of vacuum and the running pump is just holding that level, then it is not actually evacuating any mass. If it's not evacuating mass, then it's not removing any remaining water vapor. Basic conservation of mass.
Holding vacuum in a closed system over time CAN turn liquid water into vapor. In my case, that would have manifested as a drop in pressure. In the case of a motor pump holding constant gage vacuum, that extra water mass would be evacuated. Since my vacuum reading didn't drop any in 20 hours, it's reasonable to conclude that there was no liquid water in the system at the time I applied vacuum. So the difference between my vacuum pressure and the 'proper' one is limited. If we knew the total volume of the system and the humidity of the air in starting conditions we could calculate the actual water mass difference between -25 and -30. But I didn't bother because the answer is clearly: negligible and well within the desiccant capacity.

 

manualman,

From physics class you would know the relationship of pressure, volume and temperature on a gas. You would also know that air contains a lot of water. You can see the water condense on the can of refrigerant when it cools. The same thing happens to the inside of the system when you open it up. Evaporation cooling is how the system works, and it works well. The massive pressure reduction of opening the system has the offsetting relationship of reducing the temperature because pressure and temp are on opposite sides of the equation (and we can ignore volume because the size of the system is constant. The systems cools quickly, then as it warms back up air is drawn and water vapor condenses on all those cool surfaces. The air entering just the drier desiccant is usually enough to reduce a large capacity of the desiccant, which is why they want you to replace it when you open the system.

The reason that professionals use a good vacuum pump (one that can drawn down to very low levels) is because water only changes back to air at very low vacuum levels at room temperature. Very much lower vacuum levels than any hand pump can reach. The reason the vacuum remains the same is because no water is evaporated. If you evacuated the system and back filled with pure nitrogen and let the system stabilize slowly and keep purging pressure slowly until the system was at equilibrium with temp/pressure of the ambient air, you could possibly assume that little water vapor entered the system if you capped every part of the system as soon as it was opened, but there are still parts of the system that are open to the air, particularly the parts you replace. Generally only the HVAC pros purge with nitrogen on larger systems, and they still vacuum it down carefully afterwards.

In large vacuum chambers it is very hard to get enough vacuum to get all the water out, so they compromise by using a very cold hvac system system in one corner of the chamber to condense the water there and keep it controlled.

 

Why not rent a vacuum pump from autozone for free, buy three cans of refrigerant, and do it right? If you're DIY it's cheap. If I had a shop that would do that for me for $60 I'd gladly pay it. Around here an AC service is $150.

 

CNN, once again, you have saved me time and money. I'll be replacing the compressor this weekend.

My question is about the air gap. Is it necessary to adjust it down to 0.3mm? What will happen if I leave it at the factory standard? If it is necessary, how do I adjust it?

 

I'm doing a compressor replacement and found you article full of great info but I have a question. What is the torque used to fasten the 5.5mm bolts that hold the high pressure hose adapter?

 

Not sure, but those are crazy tight coming off. Make sure you have the right socket and soak them in penetrating oil. This may be the most risky part of the job. You can just snug them up when reinstalling. They are hard to strip out, but I commend you on trying to find the specs.

 

Does this procedure apply for 4th Gen Odys? (2011-2017)

I'm mainly concerned whether or not I can pull the compressor out through the passenger whell well or if I have to go through the bottom, after removing the frame brace.