'02 300M A/C overhaul

I'm about to tackle the replacement of the evaporator, heater core and receiver-drier on our '02 300M.
Questions:
1. The service manual says to drain the cooling system, but could I get away with simply clamping the heater hoses shut before I disconnect them from the heater core?
2. Other than the 1oz. of oil in the receiver-drier and 2oz. that is (or should be) still in the evaporator, do I need to replace any additional oil that might have been lost when it went "Pffft!" and stopped cooling? Is there any alternative to removing and draining the compressor, then calculating the amount of new oil I need to add?
Perce
Reply to
Percival P. Cassidy
"Percival P. Cassidy" writes:
Probably not. You really want the coolant out of the heater core and heater core lines before you take that apart, unless you really like the idea of taking a bath in what spills while you're working on it -- and when did you last change the coolant, in any case? Whenever I do a job that calls for draining and refilling the coolant I figure it's a good time to change it.
I've never seen a good way to estimate this....
Reply to
Joe Pfeiffer
I'm pretty sure I had the coolant changed when I had the timing belt, idler pulley, tensioner and water pump replaces (approx. 100K miles, and the car still has only 118K miles, so I don't think it's due for a coolant change for a good while yet.
You mean that even the method described in the service manual isn't reliable? I know it's not possible to have a dip stick in the compressor, but wouldn't it have been possible to have a sight glass?
The table of component capacities in the service manual has an item "Line Blown" with a capacity of 1.5oz.; is it safe to assume that that 1.5oz. is still there? Is simply adding 3oz. (1oz. for the receiver-drier and 2oz. for the evaporator) as good a guess as any?
Perce
Reply to
Percival P. Cassidy
Did you ever download the sections of the factor service manual that I posted links to back in April?
Could get messy. You can drain the system and save the coolant to pour back in if it's not too old.
No idea.
I've not had to deal with any of those issues with my '00 300m. AC still works great - but I don't use it that much. Over the course of a year, I probably use the defrost setting more often than the A/C (in the summer I tend to like having the windows open, even if it's hot outside. I do mostly short trips - not much long distance highway driving where I would have the windows shut and the A/C on).
Are you the one with the 300m that has really low milage - or am I thinking of someone else here?
Reply to
MoPar Man
Yes, I did, and I'm sorry I didn't thank you at the time. But the '02 manual I had already is, understandably, more in conformity with my car.
So far I am managing without AllData or Mitchell, but I did find one point at which the official manual had one particular step in an impossible place: to remove a screw that was not accessible until several steps later.
I'm all set to remove the instrument panel next, but it's very hot, so I came in to cool off.
Replaced about 20K miles ago.
I tolerate the heat much better than SWMBO does, but it was definitely a nuisance not having demisting/defrosting in the winter.
Now at 118K miles. Not a huge mileage, but I've read that Chrysler evaporators frequently develop leaks.
Perce
Reply to
Percival P. Cassidy
Perhaps me? Original owner of a 2000 3ooM with 35,000 miles on the odometer. Only problem I've had with mine is the foam surrounds detaching from the baskets on the 6 1/2 inch front door speakers.
Steve
Reply to
Steve Stone
I have at last got everything apart and have almost all that I need to restore it to normal operation,
Removing screws, nut, bolts and air-circulation pipes, and disconnecting electrical connectors to remove the whole instrument panel/dashboard was tedious but comparatively straightforward, except that not all the connectors' "latches" worked the same way: some were press-to-release, whereas others had to be pried outward to release the connector.
The real nightmare was disconnecting the heater hoses at the firewall: the spring hose clamps were extremely difficult to release with the tools I had and not easy to release even with the special tool I bought. Even after moving the clamps out of the way, getting the hoses off was not easy. I ended up slitting the heater-to-block hose and buying a new one, but I persevered with the other one because of the difficulty of getting at the other end to remove the clamp. The service manual said to replace the clamps by new ones of the same kind, but nobody seems to sell that size, and even the Chrysler dealer said they just discard them and use regular screw hose clamps because the fancy spring clamps fail too often; it's a good job I happened to have a stash of the right size regular clamps, because they are very difficult to find just now as a result of the lawn-sprinkler maintenance being performed during our heatwave.
The heater core I had bought from Advance Auto Parts too long ago to return fits but has a pathetically small surface area compared to the original; maybe it would be fine in a climate where the winters are not as severe. I now have from NAPA one that looks identical to the original.
The evaporator core I had bought from Advance too long ago to return turned out to have a different style of connector from the original, and at the NAPA Web site I discovered that there had been a change during the model year and that I needed one that was specified for the '03 model.
I guess I can sell the other heater and evaporator cores on eBay.
The one thing I have not been able to buy is the Styrofoam insert that goes under the evaporator. The original was in a real mess as a result of the leaking PAG lubricant, and the only way to buy it was, the Chrysler dealer told me, as part of an HVAC installation kit that had to be ordered specially (US$103), but when it arrived it did not include that item; it turned out that the parts guy did not know what Styrofoam was and was thinking of the soft foam that is used in various places in the HVAC system. They eventually found out that it comes with the genuine Chrysler evaporator (US$416) and is not available otherwise, so I'm going to make do with the original one, crappy though it may now be -- perhaps with a layer of duct tape over it.
In addition, once I removed the air cleaner I could see that a clamp holding the suction tube/hose in place was almost totally eaten away and that there was white corrosion on the tube at that point; that most likely explains the gradual deterioration of the cooling function before it finally died with a hiss. I got a replacement from Advance, who messed up the expedited shipping I requested but ended up by refunding the whole of the shipping charge. NAPA and Autozone list only the discharge hose, not the suction hose.
The receiver-drier I had bought from Advance appears to be fine.
Perce
Reply to
Percival P. Cassidy
wrote:
Once you get it all back together and working you'll feel like you just completed a moon landing. I always feared working on AC due to some unpleasant experiences years ago but recently have finally gotten the hang of it. And saving $1500 in the process is not a bad reward either.
Reply to
Ashton Crusher
Would a salvage yard have the styrofoam? I am able to find many parts at my local "you pull it" salvage yard for very little. But then again, maybe they would not have been in any better condition than the one you already have.
KM
Reply to
greybuck
It turned out that the suction hose I had purchased from Advance Auto Parts did not fit, thanks to the mid-year engineering change. I was able to return it to one of the local stores, but the only '03-style suction hose I could track down was a genuine Mopar one with a list price of $122, but I discovered "We R" Mopar" (wermopar.com), which shares a physical address with Taylor Chrysler Dodge Jeep in Bourbonnais, IL) and sells the genuine article for only $80.03. I told the customer service person the VIN of my vehicle and he was able to tell me the exact part number I needed, although I still had to order it on their Web site.
I had thought originally that I would put everything together at least to the point of being able to drive the car to an a/c specialist to evacuate and recharge the system, but I realized that if a leak were discovered at that point a great deal of disassembly might be necessary to remedy it, so I got an el-cheapo vacuum pump and gauge set at Harbor Fright (and was able to use some coupons as well, to lower the price still further) and was able to do everything myself.
Perce
Reply to
Percival P. Cassidy
I forget the actual pressures now (I actually finished the job about ten days ago), but when I checked they were in line with the table in the service manual.
Perce
Reply to
Percival P. Cassidy

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