air conditioner diagnosis/repair

[griffonks]

Sorry to bring this topic up again, I have searched but I didn't find what I need. I know little about AC, but some of you know a lot. I don't want a quick fix, I want to know how to make the system right. The AC has not worked in my 89 LX for years, I have no idea how or when it died. I think it has the Denso compressor.

Question 1) Can I locate any leaks and check the Compressor/Clutch without special equipment? Or do I need to take it to a shop?

Question 2) Should I bring it back to right for R12 or convert it to that Lousy R134?

I am about to replace the timing belt, tensioner, crank seal and water pump for the second time, I did it 65K miles ago. And thought while I was in there and greasy maybe I should replace the receiver drier and add a New Compressor and lines (if necessary), then have a shop fill and test it.

Thanks in advance!

[stephensimmons]

Sorry to bring this topic up again, I have searched but I didn't find what I need. I know little about AC, but some of you know a lot. I don't want a quick fix, I want to know how to make the system right. The AC has not worked in my 89 LX for years, I have no idea how or when it died. I think it has the Denso compressor.

Question 1) Can I locate any leaks and check the Compressor/Clutch without special equipment? Or do I need to take it to a shop?

Question 2) Should I bring it back to right for R12 or convert it to that Lousy R134?

I am about to replace the timing belt, tensioner, crank seal and water pump for the second time, I did it 65K miles ago. And thought while I was in there and greasy maybe I should replace the receiver drier and add a New Compressor and lines (if necessary), then have a shop fill and test it.

Thanks in advance!

I wouldnt knock 134a! If its done rite it will freeze you! Trust me I know, I Have white frost coming out of my vents and it will make you run it on low! Now as for leaks you can get the freon with dye it it or gat you a leak detector. As for freon I prefer 134a because you can get it easy BUT if you can get r12 in it you could do that an hope it dont leak out again an if it dose that you can still get it.

[Oldblueaccord]

On a budget down and dirty Id put new oil in the compressor and use 134a and a can of the leak stop. Mine runs on low,second speed and its been a real hot summer on otherwise original condenser and a junkyard compressor.

Freeze 12is another option.

They sell a Freon leak detector (sniffer) for under 100$.


wp

[DBMaster]

I just replaced my compressor a week ago and used Freeze 12. It's basically a blended refrigerant of R134a and just enough of, I think, R142 to carry the existing oil through the system. It's been over 100 here for the past 15 days or so and I would call the performance "acceptable." I have been measuring vent temps and it seems to be just a couple or three degrees warmer than the system was with R12, but as I said, the performance is acceptable given the much lower cost and similar head pressure with Freeze 12. As far as the "white frost" from the vents goes, that's a pretty normal phenomenon when the outside humidity is high and you are using the system on "FRESH." Actually, for years I have used the "fog" from the vents as an indication that I needed to add Freon to the system. It's not really an indicator of performance.

[Oldblueaccord]

Funny I have had that same frost out the vents and like clock work 3 days later I am adding a can of freon. My drain clogged again after a big cleaning last year and I got some nasty mold mushroom on my floor ,yuk, but mines been colder then ever had been in years.



wp

[Dr_Snooz]

When a system springs a leak, it blows freon and oil out the hole. A lot of times you can find the leak by looking for the oil smear. If it's on a rubber hose, then it's a safe bet you just need a hose. If it's on a joint, then you may only need an oring. Sometimes you can't see the leak and then it might be worth taking it to a shop, or buying a sniffer. I've had absolutely zero luck finding leaks with UV dye. The next time I have a tough leak, I'll be buying a sniffer.

To work on the system, you will need a gauge set (~$80) and a vacuum pump ($80-150 or so). Unlike a lot of jobs, where you can buy tools and learn as you go, you need some training before tackling the AC. If you don't know what you are doing when you charge it, you can blow up the freon bottle and seriously injure yourself.

It sounds like you've already made up your mind about 134 and there is a lot of R12 snobbery on this board. Here's the deal though. You probably won't notice the difference unless you are the kind who drives around with a thermometer in the vent or takes careful records of head pressures. If the system has never worked, then it doesn't matter because you don't have a basis for comparison. You're just going to be happy that cold air blows out the vents and cools the car (and it will cool the car well). In my own experience, I didn't notice a difference between R12 and 134 on the 3g and on the 4g Accord, 134 has worked a LOT better than R12 ever did.

So the difference between the two is not that great. What is a big difference is how easy 134 is to get and work with. If you are absolutely committed to R12, then you can drive/call/browse around and try to find someone to sell it to you. Then you can pay a lot of money to have the system charged and hope you got all the leaks (which you probably didn't, so double whatever it costs to fill it because you'll be doing it twice...or more). If you ever take it to anyone to have it serviced, they will want to convert it for you. If you go with Freeze 12, it's basically the same story. R134 is readily available from every store, everywhere. It's only $7/can from every WalMart. I just don't see R12 being so much better as to justify the extra bother.

The only downside of 134 is the conversion. You do have to flush the system of all the old oil and replace all the orings in the system. That's an afternoon of extra work (if you burned up a compressor, then you'll be doing all this anyway), but it's not prohibitively expensive and makes all future service a breeze. You can charge the system cheaply and take it anywhere to have it serviced. You can't say the same about R12 or Freeze 12. For me, the convenience of 134 is far more valuable than any theoretical superiority of R12.

Others will have different opinions, so you'll have to make up your own mind.

I wouldn't open the system until you are ready to fix it entirely. You don't want it to sit open and get dirt in it. Replace the drier last because it absorbs moisture from the air when the system is open and then you will need to replace it.

[nswst8]

Colorado, R134a would probaly work just fine. It did well for me in Florida and Connecticut. I converted it back to R12 in 2009 in San antonio, TX. Just to damn hot for R134a. They were using Freeze12 there as a conversion alternative.

I went to R12 because I could afford it, although it really wasn't that expensive. $12-$15 a can through Ebay. After I challenged the EPA MV609 $24.95 and 25 questions open book. Easy day.

Replace all O-rings
Flush all lines with denatured alcohol
replace receiver/dryer
evacuate & charge

Check your compressor if it is a Keihin replace it, chances of it being any good are slim given the time of being down.

These systems are easy to work on and I mean "EASY"!

[griffonks]

I think my father put away some R-12, like a dozen cans, and all his vehicles are too new to need it now. Like I said I know little about AC,and I caught the attitude on R134 from reading posts here.

So, I guess I take a look at the window and see if anything is left, follow the lines and look for grease smudges, then start the engine and have someone kick the system on to see what the compressor is doing, check for voltage etc... If I can't find the problem/s take her to a shop and pay the $100 for diagnosis. Then decide what to do as far as parts. If I replace the compressor I'll make sure it's compatible with R134-

The AC is the only broken thing in her, and though I usually drive the 3g in snow storms I want her right. If I make some $ this fall I'm gonna get her painted.

[LX-incredible]

R134a doesn't quite cut it here on our AC systems. You'd probably be fine in CO though. Another thing to remember is 134 molecules are smaller and will find their way out of a small leak faster. In cooler climates or lower fan speeds the system will cycle frequently with 134, due to the R12 expansion valve. Even "If its done rite" R134 will NEVER provide better better performance than R12

As far as price being an issue, a virgin 30 lb jug of R12 can be had for the same or less than R134. You will spend some money on the 12-16 oz cans though...

[DBMaster]

That's why I am hanging onto my last three cans of R12. If I find that the Freeze 12 needs frequent topping off, or if I don't like the performance over time I will redo with R12. That just won't leave me with anything left for top offs. I got six cans several years ago from a contact who makes frequent trips into Mexico. The stuff was $2.50 a can there. I have heard rumors that some of this "R12" can turn out to be propane, but I did at least check the stuff to see if it was flammable before I put it into my system. LOL.

[ecogabriel]

I went through the posts and you have pretty much got all the info you may need. The car's service manual should have extra info on how to troubleshoot your A/C.

NAPA has an online guide on A/C capacities -oil and refrigerant,

http://www.napabeltshose.com/news/index.cfm?location_id=1078&id=1517&show=newsitem


I would add one little detail: whatever work you have to do with your A/C,
1) REPLACE YOUR PORT VALVES
2) Make sure the PORT CAPS are installed, tightened, and that they seal properly.

My civic A/C leaked through those little bastards. I replaced them; however, don't count on perfect tight seal even when new. One of them had a tiny little bit of a leak after charging the A/C. That is why you need good valve caps.

My 3G also leaked through the valves but in that case a good set of caps has held the system together just fine. Some idiot had recharged it and forgot to replace the caps.

[Oldblueaccord]

I just stuck with the original ports. I made my own hose with a r12 end and the r134 fill end. I never really liked the adapters.


Id like link to where you can get R12 cheaper then 134a because I could make some money off that deal in a heart beat.




wp

[LX-incredible]

Id like link to where you can get R12 cheaper then 134a because I could make some money off that deal in a heart beat.

http://www.craigslist.org/

[griffonks]

Thanks LX-incredible- I just spent $300 for engine and chassis manuals for my 84 FJ60 Land Cruiser or I'd go get those tools. If I get paid (I'm on commission) before the tools are gone I will get them.

[griffonks]

I went through the posts and you have pretty much got all the info you may need. The car's service manual should have extra info on how to troubleshoot your A/C.

NAPA has an online guide on A/C capacities -oil and refrigerant,

http://www.napabeltshose.com/news/index.cfm?location_id=1078&id=1517&show=newsitem


I would add one little detail: whatever work you have to do with your A/C,
1) REPLACE YOUR PORT VALVES
2) Make sure the PORT CAPS are installed, tightened, and that they seal properly.

My civic A/C leaked through those little bastards. I replaced them; however, don't count on perfect tight seal even when new. One of them had a tiny little bit of a leak after charging the A/C. That is why you need good valve caps.

My 3G also leaked through the valves but in that case a good set of caps has held the system together just fine. Some idiot had recharged it and forgot to replace the caps.

Thanks to all of you for the info like this!

[rc00netzero]

Another suggestion: Definitely get a GOOD gauge set, but - Autozone's tool loaner program includes a decent (although not pro level) vacuum pump which can be borrowed for a $200 deposit and returned when done. Worked great for me. This avoids investing in a tool that (if all goes well) you won't need again for years. The gauge set, however, can be used for both diagnosis and topping off the system occasionally ( assuming you don't find all the leaks - which happens ). If you get it right, that won't be too often. I found the rubber stoppers from Lowe's useful to keep trash/moisture out of the components while the system is open. Carefully check the condition of the discharge hose before reusing -it takes the most abuse (it goes from compressor to evaporator). Above all with AC - cleanliness is crucial! Any trash that gets in will mess something up.

[ecogabriel]

Another suggestion: Definitely get a GOOD gauge set, but - Autozone's tool loaner program includes a decent (although not pro level) vacuum pump which can be borrowed for a $200 deposit and returned when done. Worked great for me. This avoids investing in a tool that (if all goes well) you won't need again for years. The gauge set, however, can be used for both diagnosis and topping off the system occasionally ( assuming you don't find all the leaks - which happens ). If you get it right, that won't be too often. I found the rubber stoppers from Lowe's useful to keep trash/moisture out of the components while the system is open. Carefully check the condition of the discharge hose before reusing -it takes the most abuse (it goes from compressor to evaporator). Above all with AC - cleanliness is crucial! Any trash that gets in will mess something up.

I could not get my hands on one of those in my local Autozone. They don't even know what I'm talking about when asking for the pump... I got someone that does HVAC in the apartment complex I used to live to pull a vacuum fortunately... but it is good to know that they can be loaned somewhere

[88Accord-DX]

I'll add a few things I guess... IF you want to see what kind of leak you have, rent a vacuum gauge & A/C gauges from Autozone.. (work there p/t) Pull a vacuum for 30 minutes on it, to get -30 hg. on the gauges. Cut the pump off & watch your gauges. If the gauges drop less then -25 hg. in 5 to 10 minutes, you have a small leak. You can spend more money to find the leak, like shooting dye in the system & buying glasses & ultra-violet light to see it..(that is if it is large enough)
The more expensive route is a pricey sniffer... Cheap ones don't work well on real small leaks.... If your on a buget, you can shoot in some Super Seal & then push some FREEZE-12 behind it, so you don't clogg the service port.(need to a retro-fit to do that) FREEZE-12 is only sold at certain stores & runs around $16 for a 12 oz. a can & is sold at most Naps parts stores.

I have cleared all the oil out of a system before by running compressed air though the lines for a few minutes on a rubber tipped nozzle & then pulling a vacuum afterwards to get the moisture out.
If you run some A/C flush in the system, you can get away without replacing all the O-rings..GOOD A/C work can get expensive if done right by a shop!!(but replacing all the O-rings is the way to go) Also, anytime you retro-fit the system, you will need to get OUT all the old ester oil & flush all the lines out along with REPLACING the receiver/drier... You need to remove all the OLD Ester oil to convert to R-134A.. Both Ester & Pag oil do not mix well & can cause problems in time. Depending on how many parts you replace, make sure you put the right amount of oil in it. (not just for the compressor)
Injecting compressor oil requires another tool & is best after a vacuum, but can be done with a charged system, but requires the oil injector which is plugged into the low side port.

[LX-incredible]

I'll add a few things I guess... IF you want to see what kind of leak you have, rent a vacuum gauge & A/C gauges from Autozone.. (work there p/t) Pull a vacuum for 30 minutes on it, to get -30 hg. on the gauges. Cut the pump off & watch your gauges. If the gauges drop less then -25 hg. in 5 to 10 minutes, you have a small leak. You can spend more money to find the leak, like shooting dye in the system & buying glasses & ultra-violet light to see it..(that is if it is large enough)
The more expensive route is a pricey sniffer... Cheap ones don't work well on real small leaks.... If your on a buget, you can shoot in some Super Seal & then push some FREEZE-12 behind it, so you don't clogg the service port.(need to a retro-fit to do that) FREEZE-12 is only sold at certain stores & runs around $16 for a 12 oz. a can & is sold at most Naps parts stores.

I have cleared all the oil out of a system before by running compressed air though the lines for a few minutes on a rubber tipped nozzle & then pulling a vacuum afterwards to get the moisture out.
If you run some A/C flush in the system, you can get away without replacing all the O-rings..GOOD A/C work can get expensive if done right by a shop!!(but replacing all the O-rings is the way to go) Also, anytime you retro-fit the system, you will need to get OUT all the old ester oil & flush all the lines out along with REPLACING the receiver/drier... You need to remove all the OLD Ester oil to convert to R-134A.. Both Ester & Pag oil do not mix well & can cause problems in time. Depending on how many parts you replace, make sure you put the right amount of oil in it. (not just for the compressor)
Injecting compressor oil requires another tool & is best after a vacuum, but can be done with a charged system, but requires the oil injector which is plugged into the low side port.


Mineral oil was what was used in all R12 systems. PAG and ester can be used with R134a. I only use double end capped PAG 46 on our systems. Works great with R12 as well.

Why go with freeze12 when you can easily get R12 for less? Most shops wont touch anything thats not R134a or R12. With most replacement blends, components will leak at a different rate, decreasing performance over time.

Adding stop leak is never a good idea.

[88Accord-DX]

Mineral oil was what was used in all R12 systems. PAG and ester can be used with R134a. I only use double end capped PAG 46 on our systems. Works great with R12 as well.

That's right, mineral oil is used on all R-12 systems...

If the compressor oils are mixed or one compressor oil is used in a system that requires the other, the refigerant will seperate from the compressor oil & not circulate within the system. This can damage the A/C compressor and cause abnormal A/C compressor vain noise. Mixing Pag oil with mineral oil or using PAG oil instead of mineral oil in an R-12 system can lower the durability of the Nitrile butadiene rubber & or Flourine rubber O-rings. If a NBR O-ring is used in a R-134A system, the R-134A will lower the durability of the O-ring. If a fluorine rubber O-ring is used in a R-134A system, the R-134A will disolve the O-ring and cause the refrigerant to leak.

[LX-incredible]

Not sure with the Keihin, but the Denso compressors on our cars are swash plate (no vanes).

Double end capped PAG can be used with R12 with no issues. PAG is carried just fine by the R12. The problem is it reacts with the chlorine. Double end capped doesn't. Standard PAG also absorbs moisture, making it retarded to use on any system anyway.

I always perform a complete system flush with any conversion or compressor failure. Oil mixing wont be an issue if the system is properly flushed.

[griffonks]

I'll add a few things I guess... IF you want to see what kind of leak you have, rent a vacuum gauge & A/C gauges from Autozone.. (work there p/t) Pull a vacuum for 30 minutes on it, to get -30 hg. on the gauges. Cut the pump off & watch your gauges. If the gauges drop less then -25 hg. in 5 to 10 minutes, you have a small leak. You can spend more money to find the leak, like shooting dye in the system & buying glasses & ultra-violet light to see it..(that is if it is large enough)
The more expensive route is a pricey sniffer... Cheap ones don't work well on real small leaks.... If your on a buget, you can shoot in some Super Seal & then push some FREEZE-12 behind it, so you don't clogg the service port.(need to a retro-fit to do that) FREEZE-12 is only sold at certain stores & runs around $16 for a 12 oz. a can & is sold at most Naps parts stores.

I have cleared all the oil out of a system before by running compressed air though the lines for a few minutes on a rubber tipped nozzle & then pulling a vacuum afterwards to get the moisture out.
If you run some A/C flush in the system, you can get away without replacing all the O-rings..GOOD A/C work can get expensive if done right by a shop!!(but replacing all the O-rings is the way to go) Also, anytime you retro-fit the system, you will need to get OUT all the old ester oil & flush all the lines out along with REPLACING the receiver/drier... You need to remove all the OLD Ester oil to convert to R-134A.. Both Ester & Pag oil do not mix well & can cause problems in time. Depending on how many parts you replace, make sure you put the right amount of oil in it. (not just for the compressor)
Injecting compressor oil requires another tool & is best after a vacuum, but can be done with a charged system, but requires the oil injector which is plugged into the low side port.

I appreciate all the info! not just from 88Accord DX but from all of you!

[ecogabriel]

If you are planning on doing the timing belt and seals don't forget the cam seal (you mentioned the crank seal only)

Since you'll be there anyway, why don't you get the seals for the oil pump and replace them? They are cheap even if you get OEM; I got mine from Rockauto and they were Honda originals down to the bags.

It's cheap insurance to keep the old faithful cars on the road. just my 0.02