rahjah

I have a leak somewhere in my a/c system. I charged it last summer and added some leak sealer and it worked all summer. It is not working now and I have decided to replace all of the orings in the system and have it charged professionaly at a shop. I have a factory service manual but I did not see a section that specifically deals with replacing the orings. I have a friend that is a mechanic that will be helping me and we have most of the tools that any average car enthusiast would have access to. My question is, has anyone here done this before? If so, is there anything special that I need to know? Any information is greatly appreciated.

Mikester

Yes- I have done it. Once when I did the digital climate control, and again putting it back together with the SR swap.

Here is what you need to know-

Make sure the system is completely depressurized before doing ANYTHING- just because the AC doesn't work does not mean there is zero pressure... Just not enough to allow the compressor clutch to engage.

Once you have depressurized the system... At either of your pressure ports (one by exhaust manifold, one in front of condenser), you can pressurize the system with compressed air, then use some kind of leak-detector (soap bubbles) to isolate your leak.

If you have never messed with any of your connections, I'd wager your leak is somewhere in the condenser- in which case it will need to be replaced.

1. Replace the filter/drier (little canister by battery tray with pressure switch in it)- it comes with new O-rings. **Always do this anytime you break the system open!!!)

2. While old the filter/drier is completely out, run ac system solvent thru both sides of the system (comes in a can, available at any auto parts store), then blast the whole system out with compressed air to completely clear & dry it out... You will be shocked at the amount of 'crap' that will come out of your 20yr old lines- ESPECIALLY since you polluted them with stop-leak on top of everything else!

3. Drain the compressor of all the old oil- there is a drain plug on it.

4. Service the compressor with either Ester or PAG oil (Available at auto parts store, they should tell you which you need)... The quantity you need to put in is available online.

5. Get an o-ring kit from O'Reilly, Vatozone, Rock auto etc if you want to do the rest of O-rings the system... They are cheap; and you should definitely do this if replacing the condenser.

6. Connect everything up. Remember- O-RINGS MAKE THE SEAL- CONNECTIONS DO NOT HAVE TO BE GORILLA-TIGHT... JUST TIGHT. If you want to be ate-up, I am sure the torque values are in the FSM somewhere. And use backup wrenches when tightening as well.

7. Leak check the system again.

8. If all goes well- have the system charged. After a fresh purge/clean/servicing... your AC will smell fresh; and probably be 10-times colder than you ever could imagine in an S13...

Hope this helps...

Anyone else, if I forgot something, please chime in.

Mike

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TailHappy13

What do you typically do with the oil (as far as disposal goes) once you've removed it from the system?

rahjah

Mike, thanks for the info, it was very thorough. And that is a good question about the crap that is going to come out of the system.

rahjah

Also Mike, as far as pressurizing that system with compressed air is there any special adapter that you would use to do that? I ask because I do like the idea of determining where the leak is before I start replacing parts.


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Mikester

It's oil. Dispose of it like any other. I usually just dump it in with my motor oil. It's usually only a cup or so that comes out.

You can always take it to the AC shop you want to charge the system to do that. What they will do before charging is put a complete vacuum on the system using an adapter & vacuum pump. If it holds a vacuum; it will hold pressure. The reason they do this is to ensure the system has a good seal... and to ensure there is no actual AIR in the system due to air having completely different properties than the refrigerant. They will tell you real quick if it's leaking.

The key just like any other thing is DON'T SKIMP. If it leaks, don't use stop leak- fix the leak

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rahjah

That makes sense, thank you.

Juantwo3

Before you start throwing parts at it do this first


1. Check all your fuses related to the ac

2. check to see if your ac compressor is getting power and ground

3. with the car off stick your hand down there and make sure your ac compressor insnt seized the pulley and the clutch spin freely should be a little hard but not completely seized

4. hook up a/c gauges check your high and low pressure (if you have gauges)

5. open both high and low pressure lines and hook up a vacuum pump until the system is completely empty then close both high and low pressure valves (on the gauge) grab the end of the line that was connected to the vacume pump and go to autozone and buy some a/c oil/dye ad just a little bit open the blue valve for one quick second then close it to allow it to suck in the oil/dye then hook up that same line to a Freon tank or whatever your gona use that has free on and charge it. Open only the blue valve and leave the RED ONE CLOSED. turn on the car accelerate and let it get cold.

now drive the car until there is no more cold air then grab a black light flash light and some neon yellow glasses and SOURCE the leak!!!!!!!!
(fallow all the lines related to the a/c ,to the compressor,condenser, and drier. even far back into the fire wall)
if you cant find a leak there is a good chance your drier is clogged up given that you just told us you added some stop leak micky mouse stuff.

i apologize in advance if i didnt make any sense im not very good at explaining stuff im more of a hands on person


anyone else let me know if i left something out

Zeratul

Page HA-38 in the FSM has a diagram of all the o-rings, wrench sizes and torque specs for the A/C system.

feito

pressurize your system (with as much pressure as u can) like that guy said earlier and check all your connections with soapy water. If your a/c condenser is leaking you should be able to get it fixed at a radiator shop, should run you under 50 bucks for the repair pressured tested and all, i wouldnt replace it unless you buy a nissan one cuz most aftermarket ones suck. But im betting it's going to be your compressor, check it with the soapy water, spray all of it and check for leaks right in the middle where it bolts together, then come back and let us know what u found.
gl

rahjah

I was able to get my hands on a vacuum pump and a set of manifold gauges. The a/c system was already empty so I installed the high side r134a adapter and vacuumed the system. I let the pump run for about 45 minutes and afterwards it held vacuum for aproximately 1 hour. I proceeded to charge the system. According to the r12 to r134a conversion table that I found online, I needed aproximately 25 ounces of r134a. I used a 20 ounce can which was more that enough to kick the compressor on. I ran the a/c for 15 minutes with a themometer in the center vent but did not get a drop in temprature. The next morning I evacuated the system again, pulled a vacuum and this time it only held for about 10 minutes. I have decided to begin repairs and have already removed the receiver drier and will replce it and all of the orings in the lines and at the compressor and condenser. The receiver drier had some nasty black chunks of what I assume to be all of the stop leak that I pumped the system full of last year. I will replace these parts and report back.

Mikester

^^Those nasty black chunks are bits of the 'crap' I told you will come out of the lines when you clean/purge the system... When you do this, you will also need to drain/re-service the compressor with PAG oil. If the system only held pressure for 10 minutes or so, you need to isolate the leak before even attempting to recharge it.

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reeskm

Hey Mikester (or anybody). Out of curiosity do you know if:

- a RHD 180SX would have come with the A/C electric fan by the condenser? Mine is a 91 RPS13 and does not have one. I can't see any evidence of it being removed but I thought s13s come with an extra A/C fan...
- what refrigerant to use? would a JDM car use exact same system as USDM?
- can the car be upgraded to new refrigerant, or do you need to use the old stuff?

Normally here in Canada the weather is cold enough to not need A/C, but in the summer it can get very hot and A/C would be lovely. I really want to get my A/C working again!

Mikester

IIRC, the 180sx has a very small condenser fan on the fwd side of the condenser, USDM cars have a condenser fan bolted between the radiator and the clutch fan in the engine bay.

Given what you are doing, you can do a full clean/purge & go with R134a.

Since I swapped my SR in, I bought a new condenser; and am using a 12" mishimoto electric fan as the condenser fan:



Not the best pic, but you can see it mounted to the radiator inside the shroud.

If you need a spare 180SX compressor, PM me- you can have it for the price of shipping. Since I put everything into a USDM car, I only needed Cody Ace's adapter setup to make the USDM stuff work.

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reeskm

Thanks! Well I have a good mechanic that's an A/C wizard so I'll just trust him. He said he checked my car out and it won't be any issue to charge it up. Naturally tho I'm worried that I'll be seeing him again in one year! LOL
So that's why i'm super interested in this thread.

I actually have 2 spare compressors from guys that recently threw them away because of their track cars. People rarely keep a/c here when it fails. I'm gonna try them first and if they don't work, I'll definitely take you up on that compressor!

Cheers,
Rees

rahjah

So my oring kit and my receiver drier came in today and I will be installing them this weekend. I will ensure that the system holds vacuum before I recharg it this time and I have another question. When using manifold gauges I am comfortable with the vacuuming portion but when recharging I can not find a good answer on whether or not you add refrigerant with the low side open only. If anyone has good information on this I would appreciate the help like always. Again, my question is when charging, do both the high and low side valves on the gauges need to be open or just the low side? Thank you.

rahjah

I think I just found the answer to my question but if anyone still has any input please feel free to leave it. Thanks.

Mikester

Charge it on the low side.

BTW MAKE SURE you purge/clean the lines out before adding new refrigerant- and drain/service the compressor. You will thank me for this

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rahjah

Mikester, I am glad you chimed in. I remember someone saying to drain the compressor before. Does this require removal of the compressor or does it have a drain plug?

Mikester

There is a drain plug near the bottom and a fill plug on the side or top. It's really easy to remove- and since you are changing out the o-rings, you could go ahead and remove it, knock out the servicing; and put a new belt on while you're at it.

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rahjah

10-4, thanks for the info!

rahjah

Ok, last question (until the next one) I swear. New oil for the crompressor? I can't find a good answer online and I have been told that PAG 100 is the medium viscosity oil suitable for most retrofits. Is this accurate? I also failed mention that I work for an auto parts retailer and should have easy access to whatever I need. Thanks again.

rahjah

I looked up a 96 model in our system at work and it calls for PAG46. Maybe I will use PAG46.

Mikester

^^IIRC, they all take the same type os oil for R134a

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rahjah

Mikester, I have removed my compressor and drained all of the old oil from it. Tonight, I will be installing all of my new o'rings and my new drier. I was wondering if you could tell me when putting the new oil in the compressor how do I fill it up? I feel like if I filled up the compressor on my workbench the oil would leak out during reinstallation. Is the correct way to fill it with new oil to reinstall it and then fill it with new oil through the drain plug using a hand pump? Thank you again for all of your help.


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racepar1

Why did you drain the oil from the compressor??? You don't have to change the compressor oil...

To re-fill it you pour the oil in through the holes for the A/C hoses. There is no dipstick or sight glass to tell when it's full. You need to look up the spec for how much oil is supposed to be in the compressor, measured in ounces, and add about that much oil. I wouldn't add quite as much as the spec says though. It's pretty impossible to drain ALL the oil out, so there's probably at least an ounce or two still in the compressor.

rahjah

Whoops, my bad. I was under the impression that the idea was to remove all of the old oil, refrigerant and contaminants from the system. After I reinstall the pump I will add the fluid through the holes were the lines hook up. Thank you.


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racepar1

Add the oil with the compressor un-installed. It will be a bitch once you put it in...

rahjah

I got everything put back together last night, vacuumed the system and went to bed. Six hours later, I got up and found that the gauges had not moved from last night. I guess the next step is charging.

Mikester

It's 20yr old refrigerant oil lmao... ABSOLUTELY good to remove it all & put fresh stuff in. Makes a HUGE difference in how the system operates.

I serviced mine w/the compressor out; and the way it goes in, it won't leak out during reinstallation (It's not really that much to where it will leak out). With the compressor out, you can drain/fill via the bolt on the side... or top...

Once he cleaned/purged the rest of the lines & replaced the filter/drier, the system definitely needed a fresh oil supply... Especially since once you clean/purge, there is no real way to tell how much residual oil was left in the compressor itself as the oil circulates along with the refrigerant. Best thing to do with a dry (or damned near dry) system is to put in a full supply. They system only takes a few ounces; so with a fully purged system & fresh F/D, there is prolly less than an ounce at best in the compressor once drained.

^^Exactly!!! Could not imagine trying to service it any other way... that would have to be a royal PITA lol

Sounds good man! GL!

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