AC compressor seized?
 

Was on the highway tonight when I heard an awful sound coming from engine bay. I felt the car losing power, so threw it in neutral and coasted to the shoulder. I was smoking pretty good at this point. Eventually the engine died, and would not turn over again. The source? Ye old Delco compressor.

I cut the belt off and continued on my way.

I did not know this could happen!

Wasn’t using AC, though have been experiencing an electrical issue on that fuse circuit (may not be related)

I’m assuming my compressor is toast?

yep

Had the same thing happen to me a few years ago at 2 AM in the morning. I only drove about a half a mile until I could pull over but the compressor pulley shaft was starting to glow red already..... Not fun.

Happened to me also maybe 10 years ago but barely made it home with lots of noise.

Bet you were glad it wasn't anything too serious. Those spin even when the clutch isn't engaged (as you know) so I guess eventually they can fail.

Mine did the same thing a few weeks ago, except I didn't notice any noise or power loss, just loss of AC. about 400 miles later I got home, and discovered the compressor is totally kaput, if there was plastic around the wires going to the clutch, there isn't anymore.

Get in touch with ROLLGUY about one of his sanden brackets, ditch the ancient R4 while you have the perfect opportunity!

Lol… My mind immediately went to clutch/hydraulic system. Never knew how happy I could be to find a smoking AC compressor.


Bracket + compressor right?
What are people typically paying for these?

I had smoke coming from under the hood of my 1985 CA 300D as I pulled into the driveway on a 105 F day after a 16 mile drive home from work. It was coming from the AC compressor clutch. My guess is the refrigerant pressure just got too high, which caused the clutch to slip and all downhill from there as it heats up quick. Same thing happened to our 2002 Chrysler on a 108 F day. My 300D's have only a low-pressure AC pressure switch, so I swapped to a compatible high/low "binary" switch in both. I think my Chrysler has a binary switch, but I installed a little $8 pressure relief valve (~290 psig pop) in a plugged port on the compressor to be safe. Normally, would be illegal to vent refrigerant (R-134A is bad greenhouse gas), but OK for me since I use HC refrigerant in all my vehicles so no worse than a cow fart (actually a major environmental concern).

If the compressor jams, but the clutch bearings are still OK, you can simply pull the clutch relay out to drive home. It is under the black cover on the L inner fender top in my 1984 300D. Not labelled. The other relay is for the radiator fan. In my 1985 CA 300D, you can pull out the Klima relay or unplug the clutch (down in the grub zone).

AC Upgrade Time
 

Shern ;

Did you like the AC before it failed ? .

I like my SANDEN upgrade but it's not yet perfect .

I replaced the condenser too, this makes the system shed more heat .

Honestly, I had no issues with it. Well, other than the electrical issue I had yet to solve.
After the sort of spectacular failure I experienced, I wouldn’t be comfortable installing another delco…

Sanded will def be my next move. Unlikely I’ll upgrade the condenser though.

AC Service
 

If you can, remain with the R12 .

R134a works at a lower pressure so mind whomever fills the system don't dump in the amount on the label under the hood .

The system was actually converted to 134 before I bought it.
One of the few dealer records I could find…

R134a
 

I hope it mentions how much charge they used ? .

Many here diss the R4 reliability. I think Chevy owners have more problems since their R4 is mounted up high where it gets less oil. I had a Sanden compressor on my 1985 300D for several years, but then found I couldn't tighten the belt enough because the bracket had cracked (Rollguy's 1st design). I had a spare R4, so installed that and been fine for ~5 years and it gets to 110 F here. I didn't notice the Sanden doing any better, though I used the smallest H13 Sanden (for Honda Civics). Put it in my 1964 Plymouth Valiant since. I have bought new R4's for $50 on ebay, shopping in the winter (hint) and have another on the shelf.

The main concern with R4's is getting well oiled, since no sump. The best oil for any refrigerant is probably PAO68, which you can buy on ebay (or Duracool's "Oil Chill"). Consider using a HC refrigerant like Duracool or Envirosafe, since cools even better than R-12. Ignore the internet rants about "explosive" from gomers and writers who know nothing about combustion (I've taken graduate courses). Never a fire from HC refrigerant in many millions of cars using it for several decades, plus used in home refrigerators in Europe.

Thanks for this Bill. The thought has crossed my mind.

I came across what seemed like a reasonably priced Sanden paired with one of Rich's brackets but said deal has since evaporated. TBH I was perfectly satisfied with my AC experience up until the point it detonated.

I've read enough about HC refrigerants to be a convert. Thinking a new R4 and envirosafe might be the way forward.

Are there any specific compressors you've had a good experience with?