2005 AC Condenser Replacement

Hey all,

Am planning to replace the AC condenser in my '05 and wanted to see if anyone had any comments / advice. AC has been out for about 2.5 years, which has been a bit of a struggle here in Phoenix Cost has been the primary reason for not fixing, dealer quoted about $1000 back when it originally failed. Decided to just bite the bullet and do it myself, really need to get it working before facing another summer. The problem was originally diagnosed at the dealer, who found a hole in the condenser where a rock or piece of road debris had been kicked up into it. It was fairly clear where the hole was from the accumulation of "gunk" in the area. Assuming this was AC oil collecting at the location of a slowish leak. It didn't just quit all at once, it got gradually less effective over a number of months.

Given how long its been inoperable, I'm a bit concerned about figuring out how much oil (if any) may be left in the system. Also hoping the the compressor is still ok, would appreciate any thoughts on how to check its health before repairing / recharging.

Given the threads / documents I've read do far, here is my preliminary plan:

- purchase Mini VCI (planning to get this anyway) to check for codes related to compressor or?
- purchase techinfo subscription for access to manuals
- purchase dual gauge set from Harbor Freight for $50
AC Gauges - Save on this AC Manifold Gauge Set
- purchase venturi vacuum pump from Harbor Freight to use with air compressor for $16
Vacuum Pump - AC Vacuum Pump w/ R134A & R12 Connectors
- purchase Interdynamics HYB-2 R-134a charge cans with hybrid oil ($61 for 12, hoping to find individual cans somewhere.

- purchase replacement o-rings for lines in and out of condenser, and for drier / modulator cap (need to identify part numbers)
- already purchased a replacement condenser through ebay for about $75

- replace condenser per manual, swapping over cooler drier from old condenser and replacing o-rings
- vacuum down system, check that it holds vacuum (overnight?)
- charge system

Any thoughts / guidance would be appreciated, while I'm moderately handy and have done a variety of auto maintenance / repairs in the past this will be my first time working on the business end of an AC system.

Many thanks,
Rob

 

Yeah, it hasn't been much fun, for me or my HV battery. But that's another story for another time

 

Thanks, I have come across a number of his posts and they are very informative. Still have more reading to do. I realize I'm taking some risks with non-oem condenser and oil. Will definitely share what I learn, even (particularly) if it just turns out to be "don't do what I did"

 

So... after more reading it seems like I've really got two choices on the oil front.

1) Make a guess as to how much oil needs to be added. Without disassembling the whole system it doesn't seem like there is an accurate way to estimate how much oil was lost. The repair manual specifies 1.4 oz of oil should be added when replacing the condenser, so that's probably the baseline. It will be interesting to see if there seems to be anything like that amount in the old one once its pulled, though I'm uncertain as to how easy it will be to drain/measure whats in there. If it seems much less than that, I would take that as a sign that more than the base 1.4oz needs to be added to account for loss.

2) Flush the whole system repeatedly with an appropriate solvent and work on the assumption that all of the oil is removed and therefore needs to be replaced. I've read some concerns about the expansion valve state during flush, but assuming I don't have any evidence of compressor damage my primary goal is to flush the oil out of the compressor without having to remove it. Sound feasible? I was looking at using something like this attached to my compressor:
Interdynamics FK1 - A/C System Flush Kit | O'Reilly Auto Parts
Still need to read up on the best choice of solvent.

Best I can tell complete replacement seems to be about 5oz of oil, ~3.4-3.8 oz when replacing the compressor and 1.4oz when replacing the condenser.

I will also likely replace the drier sock, and have verified its in stock locally. Sourcing the oil seems like the long lead item currently.

Also, I did check last night and it does not appear that the compressor is running. I'm assuming this is due to low pressure, but will wait and see what the mini VCI says when I get it. Assuming it confirms the compressor is disabled due to low pressure, I may go ahead and try the test procedure shorting pins 1-4 on the pressure switch plug momentarily just to verify signs of life from the compressor before starting to tear things apart.

 

Update:

Got my mini-VCI up and running last night, what a cool tool!

I did verify that the AC ECU is reporting a B1423 pressure switch DTC, so that would confirm that the AC compressor should be locked out and not running. Also got a B1421 solar circuit reported, not sure yet if that's real or just because it was dark outside

Hopefully will get to work on things this weekend, will try the test procedure to briefly short the pressure sensor to see if the compressor comes on. No errors were reported or in history related to the compressor, so hoping it will turn out to be ok.

Since I've now tracked down local sources for all tools and materials (local NAPA carries hybrid compressor oil in stock) I'll plan to wait and see what the oil situation (quantity, color, and presence of particles) looks like when I pull the condenser before deciding how to proceed re flushing or just replacing and adding oil.

Rob

 

Replacing condenser seemed to go well, but having trouble with the recharge. Had 2 12 oz cans, expected to put in one whole can and a bit of the other to get to the recommended ~16oz. First can started loading fine, got nice and frosty. After pressure switch closed, started running the compressor to circulate. Toward the end of the first can it stopped feeling cold, indicating it was no longer charging and the pressures were no longer rising although it felt like there was still fluid in the can. To be sure I swapped in the second fresh can, and it never seemed to get cold / charge any more at all.


Pressures are about 15 psi low, 125 psi high. Can see bubbles in the sight glass, and vent temps are about 44 deg on max cold / medium, about 52 max cold / high with outdoor temp around 72.

Any thoughts as to why it would stop accepting charge only part way through like that?

Rob

 

Interestingly I hooked it back up this morning and it continued to fill. Not sure what was going on there, but think I'm getting close..

 

Update: Looking promising! Sight glass cleared at about 200 psi on the high side. Continued charging about 5min more, ending up at 25 psi low, 215psi high. This is with the doors open, fan temp max cool and tech stream used to manually set compressor at 6400 rpm. Tech stream reporting evap temp at 36.5 deg, thermometer showing 39.7 deg at the center vent. Outside conditions are about 80 degrees and overcast, humidity sensor showing 25%.

May still need some more charge, but decided to stop there for the moment. Not sure exactly how the ac controller sets compressor rpm, but starting to think it modulates rpm to maintain evap sensor at about 40 degrees?

Last night with charge still low it was running compressor at 6200-6400 rpm when set to high fan max cold. With current charge it runs closer to 3600 rpm with same settings. In this state the pressures are reading 32 psi low, 165 psi high. Evap temp sensor reporting 39.7 degrees, center vent thermometer at 42.9 degrees. Site glass is still clear.

This would seem to be the test conditions specified in the TIS documentation, which would indicate the pressures are still a bit low. Given the operating temperatures I'm hesitant to add more refrigerant and risk over charging though.

 

Only things replaced were the condenser (with drier), o-rings, refrigerant and oil.

Based on the temperatures currently being reported by the evaporator temp sensor I'm assuming this is ok now. You could be right about that being the problem last night. Although it was blowing coolish with a partial charge, I'm fairly sure that the evap temp sensor never reported anything much below ambient until this morning.

To answer Patrick's question, the vacuum on the system before charging was probably not great. Was using the cheap "pump" linked above, which either wasn't working very well or was too much for my little compressor. It would only pump down for ~60s, then I would have to close the valve and disconnect the pump to let the compressor pressure recover. I was only able to maintain it at about -0.75 bar, probably about a 30% duty cycle over about 30-40 minutes.

Will keep an eye on things, but hopefully it's fixed for now