Another R4 bites the dust... - PeachParts Mercedes-Benz Forum

1980sd · #1 08-02-2011, 07:06 PM

Was fooling with one of my cars steering today and figured I'd check out the AC. The compressor seemed quiet, had about 30 psi low side at idle (I don't have a full gauge set yet.) The condenser was warm, aux fan came on...

I took off down the road for a test. 50 deg vent temps with 90's outside. Looked promising.

It ***** the bed

The clutch bearing went out and probably destroyed it.

What a POS. Good riddance to bad rubbish...

panZZer · #2 08-02-2011, 07:07 PM

Quote:

Originally Posted by 1980sd

Was fooling with one of my cars steering today and figured I'd check out the AC. The compressor seemed quiet, had about 30 psi low side at idle (I don't have a full gauge set yet.) The condenser was warm, aux fan came on...

I took off down the road for a test. 50 deg vent temps with 90's outside. Looked promising.

It ***** the bed

The clutch bearing went out and probably destroyed it.

What a POS. Good riddance to bad rubbish...

So Uhh, Can I intrest you in another

..........

leathermang · #3 08-02-2011, 10:46 PM

You must have wanted it to go out....so you have an excuse to put in a Sanden type.....

1980sd · #4 08-04-2011, 12:21 AM

Quote:

Originally Posted by leathermang

You must have wanted it to go out....so you have an excuse to put in a Sanden type.....

I may do that... Use a 508 instead of a 709...

79Mercy · #5 08-04-2011, 12:28 AM

I'm crossing my fingers on the R4 in my 1985 300D. Its a old Harrison compressor with a R12 sticker on it. System has R134 in it, and to be honest it does pretty good in the FL heat, compressor doesn't make any noise at all currently, however I have put less than 2K on it since I about it about a month ago.

1980sd · #6 08-04-2011, 09:56 AM

Quote:

Originally Posted by 79Mercy

I'm crossing my fingers on the R4 in my 1985 300D. Its a old Harrison compressor with a R12 sticker on it. System has R134 in it, and to be honest it does pretty good in the FL heat, compressor doesn't make any noise at all currently, however I have put less than 2K on it since I about it about a month ago.

On both of mine it was the pulley bearing that went out not the compressor itself. I had no complaints when my main SD AC was working. I think the bearing grease gets dry/crusty with age and causes heat which screws the whole thing up. You can get the bearing for about $20 but if the old one goes it wrecks things fast

JamesDean · #7 08-04-2011, 01:10 PM

I came across this in a forum while looking up stuff on R4's and converting to Sanden types..

Quote:

A word of advice on buying a replacement compressor: Any one you get that does NOT come from Mercedes will have the front bearing cover installed UPSIDE DOWN. Look at the cover on the front behind the clutch. It will have 4 bolts. Between 2 of the bolts will be an embossed X. This is the position of the oil hole to lube the front bearing. The R4
compressor was originally designed for GM cars with the compressor mounted
on top of the engine. The X and the inlet/outlet port is UP. Mercedes used
the compressor but rotated it 180 degrees and mounted it under the engine.
This put the ports DOWN. Then they rotated the front cover so the X is UP.
Oil does NOT flow uphill. If you use an aftermarket compressor with the X
down, you will starve the front bearing of oil. It may last a week, a month,
6 months.... depends on the quality of the bearing they put in