Getting Hot.. Time to fix AC - PeachParts Mercedes-Benz Forum

300SD81 · #1 03-14-2007, 05:18 PM

I have way too much going on already, but heres another project... The 2 metal tabs that the wires connect to on my AC clutch are broken off. I believe the system is charged and should be functional. I cannot figure out how to remove the clutch. I believe I got 12V on the wires that should connect when I checked before the winter. Are there hidden screws somewhere on the clutch, or do I have to remove the whole compressor?

rrgrassi · #2 03-14-2007, 05:19 PM

What compressor is on it?

300SD81 · #3 03-14-2007, 05:20 PM

I don't know. How do I identify it? The cars a 81' 300SD

rrgrassi · #4 03-14-2007, 05:24 PM

Well, a stubby round one is the POS GM R4. It is usually mounted on the lower left hand side of the engine. The York is boxy and looks similiar to an older air compressor, and was typically mounted on the upper right hand side.

300SD81 · #5 03-14-2007, 05:34 PM

Definitely the R4. The compressor dosen't seem to be siezed, and I have pressure in the system. Only problem seems to be the broken clutch power connectors.

rrgrassi · #6 03-14-2007, 05:42 PM

Yes, you can replace the clutch. IIRC, it is assembled with the belt pully.

The clutch assembly is not cheap, so I usually just replace the compressor, and drier.

You should be able to do the job on the car, but you will need to pull the fan shroud to give more room, and then get a piece of 1/4 in ply wood and place it by the radiator, where the shroud was, to protect it from errant wrench slips, etc. Same goes for the oil cooler. I do not remember if the clutch has to be pulled off with a puller or not. There is a center bolt that has to come out. It is a standard, not metric.

300SD81 · #7 03-14-2007, 05:57 PM

I'd prefer not to have to open the system since it appears to be charged. Should be able to get a clutch for almost nothing at the junk yard...

Edit: Just checked, $11 for clutch, $14 for compressor, will probably pull the whole thing just in case...

300SD81 · #8 03-14-2007, 06:24 PM

Do you know what size the nut is? I've slipped every size of socket I have that would fit into the center of the clutch, and found no nut... Maybe the PO removed it... What kind of puller do I need to get it off?

jbaj007 · #9 03-14-2007, 07:40 PM

The nut was discontinued on the R4 compressor. I can't tell you what year, but it was long ago. Therefore, you'll see some with a retaining nut (needs a thin wall socket) and most without the nut. Doesn't need one.

This shows you a start:http://trotliner.tripod.com/ac.html

300SD81 · #10 03-14-2007, 10:41 PM

Almost impossible to get in there without removing either the compressor or the oil cooler

If I open the system, I'm looking at at least $150 for the receiver/drier, expansion valve, o-rings, ac flush, oil, and refrigerant... My bank balance: $39.46, income: $0. Looks like another hot summer...

jbach36 · #11 03-15-2007, 01:24 AM

Do it before summer's here man, you won't get anyone to work on your car when it's hot out.

jeff

bgkast · #12 03-15-2007, 01:30 AM

Quote:

Originally Posted by rrgrassi

Well, a stubby round one is the POS GM R4.

I have one of these POSes for sale in the parts section.

300SD81 · #13 03-15-2007, 06:27 PM

Noone working on the car when its hot outs fine, I don't plan on hireing anyone... I'd just soak myself with the hose and get to work

Went to AutoZone to rent their clutch puller tool, but its ment for Ford compressors and dosen't fit on the GM... Cheapest I can find the GM puller is $40