Automotive Air Conditioning Information Forum

I've read the Evacuate and Charging procedure here.

I have a Nissan Leaf S electic vehicle (no heat pump). All the R134a has escaped.

I'm replacing the condenser (it has built in dryer) which had supposedly developed a crack but I have my doubts (but the system has been open to atmosphere for long enough that I expect the dryer needs replacing).

I'm also replacing the high pressure pipe which has definitely cracked.

I've flushed all the hoses and also flushed the evaporator (behind headwall). I have new R134a and the correct ND11 electric compressor oil.

The procedure from the service manual is listed below.

There is also a formula in the manual for how much oil to add based on what components are being replaced. The manual just says to do the math to determine amount of "Lubricant amount to be added to A/C system" and then "Install compressor and check the operation."

Since I had no idea how much oil remained I removed and drained the compressor. This means the entire system should be empty of oil. So I will need to add 150ml of ND11 which is the stated total system capacity (and 0.425kg of 134a)

My plan was to follow step 3 below, pull a vacuum and verify I don't have any leaks.

I've seen a video online discussing compressor (plus other component replacement) and they poured the 150ml of oil into the compressor assembly before reconnecting all the hoses but I'm not sure if it is safe to do this? Step 4 below implies to me that I should perform the initial leak vacuum test with the system totally empty, no oil, no R134a. Then add the oil.

I've seen videos where top off oil was poured into the yellow charging line before the R134a can was connected and the R134a basically blows the oil into the system. Should I use this same procedure to add the full capacity of oil or is there a different method?

Thanks!

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Nissan service manual procedure.


1. Connect manifold gauge (for HFC-134a) to the service valve.
2. Connect vacuum pump to manifold gauge and operate the pump. Apply vacuum to the cooler cycle for approximately 25 minutes or longer.
CAUTION:
Evacuate air for 15 minutes or more if the parts are replaced.
3. Check the airtightness of A/C system for 25 minutes or more. If pressure raises more than the specified level, charge A/C system with approximately 200 g (0.4 lb) refrigerant and check that there is no refrigerant leakage. Refer to HA-26, "Check Refrigerant Leakage".
CAUTION:
Check the airtightness for 15 minutes or more if the parts are replaced.
4. If parts other than compressor were replaced, add compressor oil according to parts that were replaced. Refer to HA-29, "Lubricant Adjusting Procedure for Components Replacement Except Compressor".
5. Charge the A/C system from a service can with the specified amount of refrigerant.
6. Check that A/C system operates normally.
7. Disconnect manifold gauge.
8. Install A/C service valve cap.
9. Refrigerant charge is complete.

Everything you are doing sounds right to me.

I would do as you've suggested, check for leaks with no oil, I'd do it with nitrogen, R1-34a is second choice, but you have to keep the charge low enough to remain all vapor. If you google R-134a Pressure-Temperature Chart you can see the saturation pressure corresponding to whatever ambient you are working in, keep your leak checking pressure below this saturation pressure => only vapor will be in the system and a leak will show as a pressure drop. My last choice would be trying to detect a leak with vacuum, unless you have a micron vacuum gauge, you just can't see a leak on standard manifold gauges unless it's a huge leak. If I had to do it with vacuum, I'd vacuum for a long time or else air coming out of the residual oil will look like a leak, and leave it for a long time maybe all day or else you will not see small leaks. It sounds like your system will be in fairly new condition, it's a judgement call about how hard to check for leaks, if everything is well trusted and finding a leak later isn't a big deal you should use judgement.

I would pour a portion of the oil in the compressor, maybe 1/3 but it doesn't matter that much. The rest pour elsewhere wherever it's feasible, maybe there is a discharge hose that nicely points up, maybe into the condenser. If you pour into the suction line, it'll be almost instantly flushed right into the compressor so the suction line is in reality the same place as the compressor.

dorkshoei wrote: ↑Fri May 27, 2022 12:21 am I have a Nissan Leaf S electic vehicle (no heat pump). All the R134a has escaped.
I'm replacing the condenser (it has built in dryer) which had supposedly developed a crack but I have my doubts (but the system has been open to atmosphere for long enough that I expect the dryer needs replacing).
I'm also replacing the high pressure pipe which has definitely cracked.
I've flushed all the hoses and also flushed the evaporator (behind headwall). I have new R134a and the correct ND11 electric compressor oil.
The procedure from the service manual is listed below.
There is also a formula in the manual for how much oil to add based on what components are being replaced. The manual just says to do the math to determine amount of "Lubricant amount to be added to A/C system" and then "Install compressor and check the operation."
Since I had no idea how much oil remained I removed and drained the compressor. This means the entire system should be empty of oil. So I will need to add 150ml of ND11 which is the stated total system capacity (and 0.425kg of 134a)
My plan was to follow step 3 below, pull a vacuum and verify I don't have any leaks.
I've seen a video online discussing compressor (plus other component replacement) and they poured the 150ml of oil into the compressor assembly before reconnecting all the hoses but I'm not sure if it is safe to do this? Step 4 below implies to me that I should perform the initial leak vacuum test with the system totally empty, no oil, no R134a. Then add the oil.
I've seen videos where top off oil was poured into the yellow charging line before the R134a can was connected and the R134a basically blows the oil into the system. Should I use this same procedure to add the full capacity of oil or is there a different method?

Sorry, DetroitAC. Posting at the same time.

Many components and procedures are essentially the same for gasoline and diesel vehicles as they are for EV's. And presuming you have all the leaks covered, let's proceed from there.

Your main concern looks to be the oil and how to install the proper amount into a completely empty system. I happen to know that ND-11 is a special POE (ester) oil for use in electrically driven scroll compressors. So you do have the correct oil for it.

Forget trying to get all 150ml (5 fluid ounces) of oil into the system through the yellow hose because it will be quite difficult and take a very long time. Pouring all 5 ounces into the empty compressor is safe and also a much better plan, and it's probably the way the factory did it on the assembly line. But if you do it this way (and before running the system for the first time), rotate the compressor mainshaft (if you can access it...maybe not) 10 or 12 revolutions by hand to distribute the oil so the compressor doesn't "slug" on initial start-up. The refrigerant will circulate the oil throughout the system, so there's no need for oil balancing, unless you choose to do so.

If you prefer the latter method, put one ounce of oil into both the evaporator and condenser, 1/2 ounce into the new receiver/dryer (Yes, I would replace the R/D with a new desiccant element.), and 2-1/2 ounces into the compressor. IMHO, there's really no need for complex mathematical calculations because the refrigerant will carry the oil throughout the system anyway, as mentioned.

Install the oil before evacuating the system. That way, you can proceed to charging without evacuating it a second time.

Thanks for the help.

Yes I was concerned about the ability to add all the oil in via the yellow charge hose. It seemed impractical/messy etc.

When I had the compressor removed I don't recall seeing any way to turn the compressor by hand but I will recheck. To remove it the right front wheel has to come off and I needed to borrow a floor jack to do this which I've since returned.

I don't have any nitrogen or any kind of leak detector. Just the manifold gauges.

There are only 4 hoses and I have them all disconnected (and have flushed them). I have all new o-rings (R134a safe) and plan to install new rings everywhere. Three hoses will be used but appear good and the fourth (metal high pressure) is new OEM.

The condenser is aftermarket. The first I bought mail order didn't fit despite claiming fitment. I should get a correct fitting one today (the one I first ordered arrived Wednesday but it was badly bent). I had the local shop order me two different styles which are supposed to arrive today.

Ideally I want to put all the new oil in (distributing it into different places is fine) before I re-torque everything with the new o-rings. I don't want to have to take anything apart after this point. I just was not sure if it was safe to pull a vacuum with only oil in the lines?

What happened is we took the car into the independent shop. They used an electric compressor safe fluorescent die and said the condenser had a crack. They then started dragging their feet on the repair and had no clue when it would be ready. Eventually I took the car back unrepaired. We drove it all winter as-is. I came to look at it and quickly found the high pressure pipe was cracked. Ordered a replacement from Nissan. I can't see signs of a crack in the condenser. Maybe it also is. Regardless after driving it all winter with it open to atmosphere I figure I should replace the condenser due to the integrated dryer.

So that's the story. Advice welcomed. I guess I do have faith that it will hold pressure, so the vacuum test with just oil before charging is more peace of mind and following the Nissan directions.

dorkshoei wrote: ↑Fri May 27, 2022 11:17 am When I had the compressor removed I don't recall seeing any way to turn the compressor by hand but I will recheck.

If it's an all-in-one unit, the electric motor that drives the compressor is housed within the same case, which means that you won't find an external shaft or flange to rotate as you would on a clutch-type compressor. The former is what I thought it might be.

dorkshoei wrote: ↑Fri May 27, 2022 11:17 am I don't have any nitrogen or any kind of leak detector. Just the manifold gauges.

In that case, add the appropriate type and amount of UV dye to the system yourself (it's a special dye for use only with electric compressors, as you mentioned) and use that for leak checking purposes after the system has run a while.

dorkshoei wrote: ↑Fri May 27, 2022 11:17 am Ideally I want to put all the new oil in (distributing it into different places is fine) before I re-torque everything with the new o-rings. I don't want to have to take anything apart after this point. I just was not sure if it was safe to pull a vacuum with only oil in the lines?

It's safe to evacuate the system with the full 5 fluid ounces of oil in it because the evacuation process won't pull out the oil.

dorkshoei wrote: ↑Fri May 27, 2022 11:17 am Regardless after driving it all winter with it open to atmosphere I figure I should replace the condenser due to the integrated dryer.

Smart idea, especially since it had been open to the atmosphere for quite some time. Evacuate it for at least one hour and preferably longer, down to 29.9 inches of mercury (InHg) or better, to ensure you remove any air and moisture from the system. Be aware that any system might hold a vacuum indefinitely, yet leak under pressure, and vice-versa. So give it a careful going over, looking for any traces of the UV dye, after you've run the system for a week or so. You'll need a pair of UV glasses and a UV flashlight to detect the dye should any leak out.

JohnHere wrote: ↑Fri May 27, 2022 3:25 pm If it's an all-in-one unit, the electric motor that drives the compressor is housed within the same case, which means that you won't find an external shaft or flange to rotate as you would on a clutch-type compressor. The former is what I thought it might be.

No worries. I appreciate the suggestion. Since it doesn't appear I can rotate I assume pouring all 150ml of oil into the compressor is a bad idea (slug). So I should distribute the oil into various parts. Compressor, condenser, hose leading to evaporator etc per previous advice.

JohnHere wrote: ↑Fri May 27, 2022 3:25 pm In that case, add the appropriate type and amount of UV dye to the system yourself (it's a special dye for use only with electric compressors, as you mentioned) and use that for leak checking purposes after the system has run a while.

Tracer TP-9811 is what the shop used. It's also not in-stock available and I would also need the application kit TP9812-BX ($200 retail, cheaper on eBay) Plus light and glasses (Harbor Freight probably) https://tracerproducts.com/hybrid-vehic ... artridges/

I understand; do a job properly or don't do it at all. I'm sure I can resell on the rest of the kit as it comes with 3 cartridges.

When I first posted I was hoping the vacuum check (per the Nissan instructions) would be sufficient to detect any leak but I was being optimistic as reading again the referenced HA-26 "Check Refrigerant Leakage" says to use an electric detection probe.

Based on what you write I should be able to order the Tracer kit mail order and in parallel add oil, seal up, follow procedure here and drive. Working off the assumption a leak is unlikely. When the mail order dye kit arrives, add and check carefully for any small leaks. It's the wife's car and she was not expecting it to be in pieces for a week (due to the incorrect fitment of the first aftermarket condenser) and she is starting to express displeasure

Thank you. I'm a bit shocked at the level of attention to detail you've put into your replies, I'm not used to it on forums and I really appreciate it!!

dorkshoei wrote: ↑Sat May 28, 2022 9:57 am Since it doesn't appear I can rotate I assume pouring all 150ml of oil into the compressor is a bad idea (slug).

Presuming that the factory does it that way on the assembly line, it might not be a bad idea. If it works for the factory, ... .

dorkshoei wrote: ↑Sat May 28, 2022 9:57 am So I should distribute the oil into various parts. Compressor, condenser, hose leading to evaporator etc per previous advice.

I would feel more comfortable doing it that way because there would be only 2-1/2 ounces of oil in the compressor instead of the full 5 ounces, which arguably might lessen the chance of slugging. I wouldn't worry about trying to add oil to the lines. I'd just add a small amount to the major components and call it done: 1 ounce each in the condenser and evaporator, 1/2 ounce in the R/D, and 2-1/2 ounces in the compressor.

dorkshoei wrote: ↑Sat May 28, 2022 9:57 am Tracer TP-9811 is what the shop used.

Yes, that dye is compatible with your electric compressor. The Forum sponsor, ACKits.com, probably also has it. Check with Tim for that and any other parts you still need.

dorkshoei wrote: ↑Sat May 28, 2022 9:57 am When I first posted I was hoping the vacuum check (per the Nissan instructions) would be sufficient to detect any leak but I was being optimistic as reading again the referenced HA-26 "Check Refrigerant Leakage" says to use an electric detection probe.

An electronic "sniffer" is the preferred way to check for leaks in many pro shops, but purchasing the device will cost more than the dye.

dorkshoei wrote: ↑Sat May 28, 2022 9:57 am Based on what you write I should be able to order the Tracer kit mail order and in parallel add oil, seal up, follow procedure here and drive. Working off the assumption a leak is unlikely. When the mail order dye kit arrives, add and check carefully for any small leaks. It's the wife's car and she was not expecting it to be in pieces for a week (due to the incorrect fitment of the first aftermarket condenser) and she is starting to express displeasure

Right...presuming you now have the full 5 ounces of oil installed, assemble the system, pour in the dye in the proper amount and in a convenient place (like into a hose end, then reconnect same), evacuate the system well, verify that it holds vacuum, then charge it to specs, check pressures and center vent temps, and give her the car back so that she can drive it as she normally does. Another leak is unlikely, as you mentioned, but always possible. However, if you don't find any traces of the dye on or around the system components and connection points in a week or two, and it doesn't lose any refrigerant, then consider it fixed. She'll forget about the slight inconvenience once she's driving again in cool comfort.

dorkshoei wrote: ↑Sat May 28, 2022 9:57 am Thank you. I'm a bit shocked at the level of attention to detail you've put into your replies, I'm not used to it on forums and I really appreciate it!!

You're welcome. We're all volunteers, donating our time and expertise to help you "get it right." Come back and see us should you have any additional questions.

JohnHere wrote: ↑Sat May 28, 2022 10:32 pm Right...presuming you now have the full 5 ounces of oil installed, assemble the system, pour in the dye in the proper amount and in a convenient place (like into a hose end, then reconnect same), evacuate the system well, verify that it holds vacuum, then charge it to specs, check pressures and center vent temps, and give her the car back so that she can drive it as she normally does. Another leak is unlikely, as you mentioned, but always possible. However, if you don't find any traces of the dye on or around the system components and connection points in a week or two, and it doesn't lose any refrigerant, then consider it fixed. She'll forget about the slight inconvenience once she's driving again in cool comfort.

You're misunderstanding. The dye is at least 5-6 days out mail order. Noone stocks locally. I doubt they will ship till Tuesday.

Car needs to be driveable by Tuesday. I'll have to put it back together and let her drive it. Add the dye later once it arrives. Obviously if it fails the initial vacuum test (pre adding R134a) or other indications of a large leak I'll have to wait.

The dye comes in small bottles, 3 bottles to a pack. If I could find anyone who stocked just the dye locally today/tomorrow I guess I could add it before connecting up the system. But I can't. Maybe a local a/c shop would sell me just 1 bottle, maybe, but sounds like a lot of calling around and again won't be done before Tuesday.

It appears the injector kit (image below) is designed to inject the dye via the low pressure access port. Obviously there is a risk to doing it this way but I'm working off the basis that with new o-rings and everything torqued to spec, I won't have a leak and so the dye will just confirm all is good, aka I can delay adding it.

I just mail ordered the kit below. If doing it the above way is a terrible idea and instead I really should add the dye before reconnecting everything I'm listening ....

I originally thought that you could get the dye in before putting the car back in service. But since you won't have the kit for several days yet, injecting the dye later through the low-side port is fine.

JohnHere wrote: ↑Sat May 28, 2022 10:32 pm

Presuming that the factory does it that way on the assembly line, it might not be a bad idea. If it works for the factory, ... .
[/quote]

They do almost always ship the compressor filled with the required oil amount for the full system. But 1st startup in the assembly plant is usually very special, takes place with the ECM being controlled at end of line tester, and they start the compressor with a sequence that gently, slowly pumps the oil out. I'd never fill one up for servicing.