[mainbearing]

Rockauto catalog is a bit different from FCP's, and says:

DENSO 4711529 w/ Clutch; 7SEU17C Style Info
From 03/2007

DENSO 4711532 w/ Clutch; 7SEU17C Style Info
To 03/2007

https://www.densoautoparts.com/part-...%5D%5B%5D=7212

Denso's e-catalog agrees with Rock's (crossover in 3/2007), so looks like lowd239's 2009 and Nando_e90's 2006 both got the correct compressors.

[Nando_e90]

Great!
Thanks for the info.

[Nando_e90]

So I already installed the new compressor a couple of days ago. I removed the oil from the new one and approximately 130ml came out, and from the old one barely 20ml came out. I added back 100ml of new oil to the new compressor. I vacuumed the system for 15 minutes and added 500g of freon by weight. The air comes out of the vents cold, but maybe 2 or 3 degrees (Celsius) higher than it was when I replaced the condenser and dryers, which was the day when the A/C system performed the best.

My question is: is 15 minutes of vacuum enough, or should I repeat the process and do a full 60-minute vacuum? That is what I was planning to do, but a friend of mine who is a mechanic advised me to do only a 15-minute vacuum, or the pump (1 stage 3.5 cfm) could bend some of the pipes or damage some O-rings. What do you guys think?

[lowrydr310]

Originally Posted by Nando_e90

So I already installed the new compressor a couple of days ago. I removed the oil from the new one and approximately 130ml came out, and from the old one barely 20ml came out. I added back 100ml of new oil to the new compressor. I vacuumed the system for 15 minutes and added 500g of freon by weight. The air comes out of the vents cold, but maybe 2 or 3 degrees (Celsius) higher than it was when I replaced the condenser and dryers, which was the day when the A/C system performed the best.

My question is: is 15 minutes of vacuum enough, or should I repeat the process and do a full 60-minute vacuum? That is what I was planning to do, but a friend of mine who is a mechanic advised me to do only a 15-minute vacuum, or the pump (1 stage 3.5 cfm) could bend some of the pipes or damage some O-rings. What do you guys think?

Is 500g the right amount of refrigerant? My N54 needs 590g, I don't recall what the N51/52 needs.

As for oil, ISTA says to add what you drained from the old compressor but at least 50ml. So if you drained 20ml from your old compressor, you're supposed to drain the new compressor and add 50ml of fresh oil. I'm not enough of a AC expert to say if it's OK for the 50ml extra you added, but my understanding is that too much oil can cause weak performance, however 50ml isn't too much relative to the total system oil recommendation.

I don't remember the ISTA instructions for how long to vacuum but I ran mine for 60 minutes, let it sit for 12 hours to confirm it held vacuum, then ran it another hour before adding refrigerant. The idea is to draw a lot of vacuum and hold it there for any moisture remaining in the system to boil off and get removed from the system. If your system was open longer than 25 hours you're supposed to replace the drier, otherwise just draw a long vacuum.

Did you confirm you had a good working vacuum pump? I did the auto parts loaner tools and went through two sets of gauges before I found one that didn't leak, and three vacuum pumps before finding one that worked. These pumps use oil which get contaminated and reduce oerformance. I had one that had a cracked cap on the second port and wouldn't draw vacuum at all.

[Nando_e90]

Originally Posted by lowrydr310

Is 500g the right amount of refrigerant? My N54 needs 590g, I don't recall what the N51/52 needs.

As for oil, ISTA says to add what you drained from the old compressor but at least 50ml. So if you drained 20ml from your old compressor, you're supposed to drain the new compressor and add 50ml of fresh oil. I'm not enough of a AC expert to say if it's OK for the 50ml extra you added, but my understanding is that too much oil can cause weak performance, however 50ml isn't too much relative to the total system oil recommendation.

I don't remember the ISTA instructions for how long to vacuum but I ran mine for 60 minutes, let it sit for 12 hours to confirm it held vacuum, then ran it another hour before adding refrigerant. The idea is to draw a lot of vacuum and hold it there for any moisture remaining in the system to boil off and get removed from the system. If your system was open longer than 25 hours you're supposed to replace the drier, otherwise just draw a long vacuum.

Did you confirm you had a good working vacuum pump? I did the auto parts loaner tools and went through two sets of gauges before I found one that didn't leak, and three vacuum pumps before finding one that worked. These pumps use oil which get contaminated and reduce oerformance. I had one that had a cracked cap on the second port and wouldn't draw vacuum at all.

Yes, 500g is what it says on the badge under the hood. Pic is a kind of low quality but is readable:


As for the oil, I don’t have ISTA so I didn’t know the exact amount from a reliable source, so I went with what the AI recommended 😅. The logic behind it was that the total system uses approx. 135–150ml, and without the compressor, the amount of oil remaining in the other components is approx. 35–50ml, so I added 100ml. But I will go deeper into that.

The vacuum pump is brand new; I got it from Amazon. I would say it’s working fine. At the beginning, it wasn’t doing the vacuum as expected, but that was because one of the hoses wasn’t tightened properly. After that, it worked well. I think I will evacuate the system, do a better vacuum, and then add the freon.
I haven’t had enough time to do a full diagnosis reading EVAP temp with INPA under different exterior conditions, but I will after that. Right now it cools, but I just don’t feel it’s enough.

[Nando_e90]

So today I did a 60-minute vacuum on the system, then tested it for 20 minutes — it was holding — so I went ahead and started recharging the system with 500g.
So far, I think it made a difference. At 8:30 PM with 27°C (81°F) outside and no rain, after 20 minutes of driving with the blower at medium speed, the air coming out of the vents was at almost 0°C (32°F). I’ll test it at noon under the sun, but I’m pretty sure the longer vacuum was what was needed.