My Better Half is very calm and peaceful and says that you dont need AC in the summer, the whole trick is to be tranquil and to think cool. In the summer she does garden work in white clothes and never gets them dirty. However I sweat like a Pig and Dirt follows me like a magnet. Until I mellow, I need AC!
In that respect:
My 87 300D Turbo (newly purchased) has a very weak AC system. I suspect the compressor must be replaced. I have a few questions to those of you with experience on these systems:

(1) Who sells the AC Compressor? Are any of you still using the original model? I suspect that this is the primary leakage area since most compressors last about 15 yrs before the seals go..

(2) Any comments on the High Pressure Hose

(3) Is this a Lost Cause due to the Suspect Evaporator on the 87's?

(4) Have any of you done this also. Here in New Jersey its very very humid and hard to endure without AC

Thanks!!
Advice on Rebuilding my 87 300D Turbo Air Conditioning System..

From the Zen Master:
If you THINK you need AC, then you DO.

Why have you jumped directly to ' weak' compressor ?
What other things have you checked ?
Which type compressor does your car have ?

From my experience with cars, the AC Compressor seals start to leak if the compressor is more than 13 to 14 yrs old, so if you recharge them, the new charge only makes the seal worse--and then you lose everything~~
I assume the compressor is a Nippendenso, I've only had the car a few weeks, and quite frankly, though its an 87, I am embarrased to drive it because I feel like some guy who just won the Lottery--I've never had such a clean white glossy car before...

It'd be helpful if you didn't post 3 topics about this in 2 different forums.

Regards,

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Brian Toscano

Yes, it is the Nippondenso that is weak and has Teflon coated pistons leading to "black death" when it fails.

My advice is to first determine whether the evaporator is leaking by charging it a using a sniffer. Then you'll know what you're getting into.

If you're going to replace the compressor, use a new one only. And yes, they are horribly expensive. Like Larry always says: flush, flush, and flush again. Then when you think you're all done, do some more flushing.

Use only R12 - the Nippondenso doesn't like R134a and will self-destruct from the higher pressures.

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Rick Miley
2014 Tesla Model S
2018 Tesla Model 3
2017 Nissan LEAF
Former MB: 99 E300, 86 190E 2.3, 87 300E, 80 240D, 82 204D Euro
Chain Elongation References

I think Rick meant to charge the system (it doesn't need a full charge to sniff) and THEN sniff out the system. Larry Bible feels UV dye is the better way to determine whether the evaporator leaks.

Your entire system needs to be evaluated BEFORE you start replacing parts. Its really throwing money down the drain if you replace parts piece meal on an a/c system.

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84 300DT Puke Yellow. Totalled after 438,000
84 300DT Orient Red. 169,000 (actual mileage may vary)
2002 Explorer EB (wife's)

If the evaporator is leaking I don't think you are going to find the problem using UV dye, at least not without disassembling the dash so that you can see the evaporator.

It sounds like your A/C is not working too well. There are about 6 million posts in the archives about A/C problems, have you done any searching/reading?

Do you have any A/C service tools? Without a leak detector, pressure guages, evacuator pump you are not going to be able to fix whatever is wrong even if we magically diagnose the problem over the internet.

I have a vacuum pump, guages, sniffer~~~

Being a little young and stupid, sometimes I just say "%^&" it I will Tear it Down and REBUILD IT before I troubleshoot--so I have great rebuilding skills, terrible troubleshooting skills..

70% of the time its usually the best thing for long term success...I know that sounds very stupid and arrogant, I apologize. But if u think about it, its true. Regardless, the compressor cant last that much longer, nor can the Hi side hose (dry rot)--
Every summer I do mini overhauls--brake calipers, timing chains, cylinder head jobs, engines, because in the winter, when I need the car, i wont have the time/ weather to do it...

Since none of my cars has over cost >2000 dollars, I guess the cost in the long trem is not that bad..

I guess why ZEN wise thats why I need AC

The rebuilding approach is more suited to the W123 and earlier cars than the W124 because of the cost of parts. When a compressor goes for about $800, you think twice.

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Rick Miley
2014 Tesla Model S
2018 Tesla Model 3
2017 Nissan LEAF
Former MB: 99 E300, 86 190E 2.3, 87 300E, 80 240D, 82 204D Euro
Chain Elongation References

I guess you all are correct--Anyway, patience wins in the end..

Like ZEN says, all things are done, by doing nothing...if I kind of just wait, and be patient and shuffle along, everything falls into place, but if I run around wild taking things apart, I will just cause myself and others a lot of trouble~~~~

I am going to slowly and thoughtfully fix the System, there is no real rush...

Most of the advice above is correct. I'd start by charging it with some R-12, which should only cost ~$50 for a can or two. See how long it takes to leak. If the system works at all now (the compressor turns, right?), you do NOT have a bad leak. A recharge might make it work fine for the rest of the summer. If it's weak again next spring, then worry about fixing it. If it only lasts a few weeks this year, then yeah you need to use a sniffer and/or UV dye to diagnose.

The compressor should be FINE as long as it is quiet. When they fail (or are failing), you'll probably know it. I wouldn't replace it outright unless you're made of money. Do not convert to R-134a. Stick with R-12. Yes it's still available. No it's not that expensive. The condenser failure is not terribly common but not rare either, let's hope you don't need to go there.

Oh yeah - make sure all the vacuum pods that actuate the ACC duct flaps work. Pull the glovebox, test all 7 lines with a MityVac. That alone can have a pretty significant effect on A/C operation. It's a good 8-10 hour job to pull the dash and replace ALL the pods (don't just change the bad ones) if it's your first time. Lots of photos on my website for this.

Another thing- make sure the condenser & radiator fins are very clean - poor airflow means poor cooling. And make sure the auxiliary fan works. If you discharge the system, replace the "green" pressure switch with a "red" switch, which triggers at a lower pressure, runs the fan more often, and keeps you cooler inside.

Finally, consider installing window tint that blocks UV and infrared thermal energy. There are clear films available of you don't want dark windows, and the clear stuff works great on the windshield too. I plan on installing the V-Kool or Huber Optik stuff this summer on most of my cars. More details on that are here:
http://www.500ecstasy.com/forums/showthread.php?goto=newpost&t=432

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Dave
Boise, ID
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