ND-8 (PAG-46) oil capacity for entire r134 AC system?

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NBender

NBender

10 Year 15 Year
Joined
Apr 24, 2010
Threads
9
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57
Location
North Bend, WA
I'm in the process of replacing the compressor, condenser, dryer and expansion valve in my AC system.

The FSM states to add the following amounts of ND-8 oil or equivalent to the system when replacing the following components.

Evaporator: 40 cc (1.4 fl.oz.)
Receiver: 10 cc (0.35 fl.oz.)
Condenser: 40 cc (1.4 fl.oz.)

I can't find any info in the FSM, on MUD, or online about the amount of oil to add to the compressor itself or what the total system oil capacity is.

My new compressor has about 90cc of oil in it now. I lost about 10cc when pouring it into the graduated cylinder so it likely shipped with ~100cc in it.

Some of my research online indicates that the compressor holds about 50% of the oil of the entire system so I'm tempted to follow the FSM and add the amounts of oil listed above directly to the components that I'm replacing and call it good for a total system amount of around 180cc.

However, the following link indicates that the total system capacity for AC systems with a nippondenso 10PA compressor is 8 fl. oz (~236.6 cc), about 60cc less than the 180cc I was thinking about adding.

http://www.johnsens.com/uploads/files/regulatory_lubricantguide4.pdf

Does anybody know what the official oil capacity for the entire r134 AC system in our cruisers is supposed to be?

Thanks,
Dave
 
Thanks Rex. I kind of felt guilty not buying my parts from Coolstream AC...until I read your sig line. When I poured the oil out of the new compressor to measure the volume, per the instructions, I only got about 100cc out of it. That would only equate to about 3.5 oz of oil, less than half of the total system capacity of 7.6 oz that you mentioned. I suppose I'll try to remeasure the oil volume and hand turn the clutch to make sure there isn't additional oil that I failed to measure last time but if I wind up getting the same amount out of it, then I'll add enough to bring the total system amount to around 7 oz. I'd rather be on the low side and add if needed rather than putting too much in.

On a side note, did Denso change the design of their expansion valves? The replacement I bought (475-0505) looks different than the one I had in their. Specifically, the old one has a a large sensing bulb on the top of it ,the internal pin looks beefier and it has 447500-0031 printed on it. The old one has no sensing bulb on top, the internal pin is thinner and it has 447500-9052 printed on the side. Unfortunately I can't upload pictures of the actual valves I have in hand right now but I pulled these images off the web as an example of what I'm talking about.

Old one looks like this:
TX0030.jpg


New one looks like this:
475-0505
 
I just pulled out a 475-0505 and it looks like the last pic, no extra tail on top. I'd guess that Denso has made a design change. Typically the most common failure on an expansion valve is that the sensing bulb looses its charge. Perhaps the new design will promote longevity?
In regards to the oil, it's pretty common to not be able to extract more than a few ounces of oil from the compressor. As long as you end up at about 7 ozs you should be fine.
 
So should I just assume that the compressor shipped with 7.6 oz of oil, extract some from it and add it to the individual components (i.e. 40cc into evaporator, 40cc into condenser, and 10 cc into drier)? BTW, I decided to replace the evap core too because I found some rotted fins towards the bottom and didn't want to risk it having a leak or failing soon after replacing everything else.
 
I'm assuming it's a Denso compressor. Since you're replacing everything but the condenser and hoses, I'd take the 40cc that would go into the condenser, out of the compressor. I'd leave all the rest in the compressor. Once you have everything buttoned up, rotate the hub of the compressor clutch a couple dozen turns to distribute the oil in the compressor and you should be good to go.
 
I'm actually replacing everything but the hoses, all Denso. I started by thinking I'd just do the condenser, expansion valve, o-rings and drier. Convinced myself I should do the compressor while I was at it and decided to do the evaporator core once I saw what it looked like. :worms:

Here's my previous thread about my AC woes a couple of years ago to refresh your memory.

https://forum.ih8mud.com/threads/1800-quote-to-fix-ac.598448/page-2#post-7673240

So I'll keep everything in the compressor, button up the system, and take it to a shop to evac and recharge. Thanks for your input.
 
I contacted DENSO to confirm that they put 7.6 oz of oil in their compressors when they ship them. The tech's reply is below.

Inquiry Type: Technical / Warranty
Questions/Comments: How much ND-8 oil is in a brand new 471-1166 compressor
when it is shipped to a customer?

Hello David,

Thank you for contacting DENSO. The a/c compressor 471-1166 has 224 cc's of oil in it.

Please let me know if you have any other questions.

Looks like Rex's memory served him correctly as 224cc = 7.6 fl oz. Interestingly, I was only able to extract ~100cc from the compressor when I poured it out to measure it per the instructions but I'm certain there was still oil in the compressor that did not pour out.
 
TX Cruiser - No, I did not see them put the 7.6 oz in. But then again do I think there are actually people physically adding 224cc to each one of the thousands of DENSO compressors being produced? No. It is more than likely an automated process with a low failure rate. With that said, I'm open to any suggestions you may have as to how to completely drain the compressor. I've tried, twice, and each time only got about 100cc out and there was clearly some left in the compressor.

Do you have first hand experience with DENSO compressors being shipped with less than the specified amount?

Thanks.
 
Hey Bender, I just received my parts for my compressor changeout. I bought compressor, evap coil, exp valve, drier, schrader kit, and a seal kit.
I'll be following your lead sir, so make it easy for me please.

I haven't opened my compressor other than to look inside the box. I saw the service valve installation section on page 3, but it doesn't do much more than tell you it must be drained and measured, they use "mandatory". The picture shows the oil just running out, ha!

I don't have a decent measuring cup yet, so I'm waiting. Any good suggestions for a decent measuring "beaker"?
 
blkprj80 said:
Hey Bender, I just received my parts for my compressor changeout. I bought compressor, evap coil, exp valve, drier, schrader kit, and a seal kit.
I'll be following your lead sir, so make it easy for me please.

I haven't opened my compressor other than to look inside the box. I saw the service valve installation section on page 3, but it doesn't do much more than tell you it must be drained and measured, they use "mandatory". The picture shows the oil just running out, ha!

I don't have a decent measuring cup yet, so I'm waiting. Any good suggestions for a decent measuring "beaker"?
Click to expand...

A Santech MT1184 will do the trick, or "borrow" one from the kitchen...
 
I used graduated cylinder that I borrowed from work but as 1972FJ55 said a kitchen measuring cup should work just fine. Please post how much oil you were able to extract from your compressor. I'm curious if my results are typical. Are you going to flush your old condenser and reuse it?
 
@NBender this might be a silly question but did you turn the ac clutch while you were draining it? If not, try that. Keep turning it and the rest should come out after doing that.


...via IH8MUD app
 
NBender said:
I used graduated cylinder that I borrowed from work but as 1972FJ55 said a kitchen measuring cup should work just fine. Please post how much oil you were able to extract from your compressor. I'm curious if my results are typical. Are you going to flush your old condenser and reuse it?
Click to expand...

Based on what Rex (1972FJ55) said, if there isn't any crud, don't flush. I hope not to find crud... I hope I don't regret not changing the condenser. My compressor is still working, but I figure it is nearing the end.

When I get started, I will post back here with how much oil comes out.

Is yours the Denso 471-1166 compressor?
 
The timing of this thread is spot on for me.

My system is open, unfortunately and so i'm going to replace the compressor and the dryer.

I wasn't able to follow the FSM's instructions to run the AC before removing the compressor because mine didn't work, i assume it's to help push the oil back through the system into the compressor....

Regardless, the FSM says to pour out and measure the oil from the old compressor and measure against what is in the new compressor. When i did this, the amount of oil that came out of the old compressor was almost zero. Very little oil. I am assuming it's up in the system.

I also do not have a new expansion valve, and flushing through the expansion valve is a bad idea. So, i'm going to flush from the front H line that goes from the compressor through the condenser and let it empty out from the dryer location. I hope to get a significant amount of oil out.

I hope that putting the entire amount of oil that came in the new compressor into the system is the right thing to do. I can only hope that the other half of the system that i'm not able to flush doesn't contain any large amount of oil.

Is my thinking correct?
 
Results are in.

I drained 120cc (120ml) from my brand new out of box Denso 471-1166 compressor. I had it fully inverted, held in a vise upside down and let it drip for a half hour. I rotated the compressor shaft in several different orientations too

Then, I drained my original compressor, and only got maybe 25cc out of it.

WTFO?

The booklet that came with the compressor says to drain both, subtract the excess, and put in new oil.
The FSM says to add 120cc with a new compressor, doesn't say s*** about draining the old and comparing.

I have no idea of the history of my truck, other than I'm pretty sure Mr. T didn't put a "made in china" pos evaporator core in originally. Somebody's been messing with this before me. The old oil looks more yellow than the new oil, but it was clear.

I'm changing:
-Receiver / Drier (FSM says to add 10cc)
-Evaporator (FSM says to add 40cc)
-Compressor (FSM says to add 120cc) <- exactly what I drained

That's 170cc of oil I should be adding.

I only drained 25cc out of my old compressor.
I didn't drain my pos made in china evaporator.
I tried to drain my receiver, but only saw a few drops when left fully inverted for one day.

I did put in 10cc of oil into the drier as I installed it. The drier seemed like it could hold that much.

WHAT SHOULD I DO? I have the system capped with plastic caps so I can inject oil when somebody tells me how much. Then I'll reattach the lines to the compressor and spin it over by hand a couple dozen times, vac it and fill it.

So, how much oil should I add?

Thanks!
 
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